Rapid Synthesis of Thiol-Co-Capped-CdTe/CdSe/ZnSe Core Shell-Shell Nanoparticles
- Daramola, Olamide, Siwe-Noundou, Xavier, Tseki, Potlaki, Krause, Rui W M
- Authors: Daramola, Olamide , Siwe-Noundou, Xavier , Tseki, Potlaki , Krause, Rui W M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191758 , vital:45161 , xlink:href="https://doi.org/10.3390/nano11051193"
- Description: CdTe QDs has been demonstrated in many studies to possess good outstanding optical and photo-physical properties. However, it has been established from literature that the toxic Cd2+ that tends to leak out into nearby solutions can be protected by less toxic ZnS or ZnSe shells leading to the synthesis of core-shells and multi-core-shells. Hence, this has allowed the synthesis of CdTe multi-core-shells to have gained much interest. The preparation of most CdTe multi-core-shells reported from various studies usually has a longer reaction time (6–24 h) in reaching their highest emission maxima. The synthesis of CdTe multi-core-shells in this study only took 35 min to obtain a highest emission maximum compared to what has been reported from the literature. CdTe multi-core-shells were synthesized by injecting 7, 14, and 21 mL each of Zn complex solution and Se ions into the reacting mixture containing CdTe core-shells (3 h) at 5 min intervals over a 35 min reaction time. The emission maxima of the MPA-TGA-CdTe multi-core-shells at 21 mL injection was recorded around 625 nm. Therefore, we are reporting the rapid synthesis of five different thiol co-capped CdTe/CdSe/ZnSe multi-core-shell QDs with the highest emission maxima obtained at 35 min reaction time.
- Full Text:
- Date Issued: 2021
- Authors: Daramola, Olamide , Siwe-Noundou, Xavier , Tseki, Potlaki , Krause, Rui W M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191758 , vital:45161 , xlink:href="https://doi.org/10.3390/nano11051193"
- Description: CdTe QDs has been demonstrated in many studies to possess good outstanding optical and photo-physical properties. However, it has been established from literature that the toxic Cd2+ that tends to leak out into nearby solutions can be protected by less toxic ZnS or ZnSe shells leading to the synthesis of core-shells and multi-core-shells. Hence, this has allowed the synthesis of CdTe multi-core-shells to have gained much interest. The preparation of most CdTe multi-core-shells reported from various studies usually has a longer reaction time (6–24 h) in reaching their highest emission maxima. The synthesis of CdTe multi-core-shells in this study only took 35 min to obtain a highest emission maximum compared to what has been reported from the literature. CdTe multi-core-shells were synthesized by injecting 7, 14, and 21 mL each of Zn complex solution and Se ions into the reacting mixture containing CdTe core-shells (3 h) at 5 min intervals over a 35 min reaction time. The emission maxima of the MPA-TGA-CdTe multi-core-shells at 21 mL injection was recorded around 625 nm. Therefore, we are reporting the rapid synthesis of five different thiol co-capped CdTe/CdSe/ZnSe multi-core-shell QDs with the highest emission maxima obtained at 35 min reaction time.
- Full Text:
- Date Issued: 2021
Compounds isolation and biological activities of Piptadeniastrum africanum (hook. f.) Brennan (Fabaceae) roots:
- Teinkela, Jean E M, Noundou, Xavier S, Mimba, Jeanne E Z, Meyer, Franck, Tabouguia, Octavie M, Nguedia, Jules C A, Hoppe, Heinrich C, Krause, Rui W M, Wintjens, René, Azebaze, Anatole G B
- Authors: Teinkela, Jean E M , Noundou, Xavier S , Mimba, Jeanne E Z , Meyer, Franck , Tabouguia, Octavie M , Nguedia, Jules C A , Hoppe, Heinrich C , Krause, Rui W M , Wintjens, René , Azebaze, Anatole G B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150084 , vital:38938 , https://doi.org/10.1016/j.jep.2020.112716
- Description: The dicotyledonous plant Piptadeniastrum africanum (hook.f.) Brennan (Fabaceae) is used in traditional medicine to treat various human complaints including bronchitis, coughing, urino-genital ailments, meningitis, abdominal pain, treatment of wounds, malaria and gastrointestinal ailments, and is used as a purgative and worm expeller. The present study describes the phytochemical investigation and the determination of the antimicrobial, antiplasmodial and antitrypanosomal activities of crude extract, fractions and compounds extracted from Piptadeniastrum africanum roots.
- Full Text:
- Date Issued: 2020
- Authors: Teinkela, Jean E M , Noundou, Xavier S , Mimba, Jeanne E Z , Meyer, Franck , Tabouguia, Octavie M , Nguedia, Jules C A , Hoppe, Heinrich C , Krause, Rui W M , Wintjens, René , Azebaze, Anatole G B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150084 , vital:38938 , https://doi.org/10.1016/j.jep.2020.112716
- Description: The dicotyledonous plant Piptadeniastrum africanum (hook.f.) Brennan (Fabaceae) is used in traditional medicine to treat various human complaints including bronchitis, coughing, urino-genital ailments, meningitis, abdominal pain, treatment of wounds, malaria and gastrointestinal ailments, and is used as a purgative and worm expeller. The present study describes the phytochemical investigation and the determination of the antimicrobial, antiplasmodial and antitrypanosomal activities of crude extract, fractions and compounds extracted from Piptadeniastrum africanum roots.
- Full Text:
- Date Issued: 2020
A novel dimeric exoglucanase (GH5_38): Biochemical and Structural Characterisation towards its Application in Alkyl Cellobioside Synthesis
- Mafa, Mpho S, Dirr, Heinrich, Malgas, Samkelo, Krause, Rui W M, Pletschke, Brett I
- Authors: Mafa, Mpho S , Dirr, Heinrich , Malgas, Samkelo , Krause, Rui W M , Pletschke, Brett I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193976 , vital:45412 , xlink:href="https://doi.org/10.3390/molecules25030746"
- Description: An exoglucanase (Exg-D) from the glycoside hydrolase family 5 subfamily 38 (GH5_38) was heterologously expressed and structurally and biochemically characterised at a molecular level for its application in alkyl glycoside synthesis. The purified Exg-D existed in both dimeric and monomeric forms in solution, which showed highest activity on mixed-linked β-glucan (88.0 and 86.7 U/mg protein, respectively) and lichenin (24.5 and 23.7 U/mg protein, respectively). They displayed a broad optimum pH range from 5.5 to 7 and a temperature optimum from 40 to 60 °C. Kinetic studies demonstrated that Exg-D had a higher affinity towards β-glucan, with a Km of 7.9 mg/mL and a kcat of 117.2 s−1, compared to lichenin which had a Km of 21.5 mg/mL and a kcat of 70.0 s−1. The circular dichroism profile of Exg-D showed that its secondary structure consisted of 11% α-helices, 36% β-strands and 53% coils. Exg-D performed transglycosylation using p-nitrophenyl cellobioside as a glycosyl donor and several primary alcohols as acceptors to produce methyl-, ethyl- and propyl-cellobiosides. These products were identified and quantified via thin-layer chromatography (TLC) and liquid chromatography–mass spectrometry (LC-MS). We concluded that Exg-D is a novel and promising oligomeric glycoside hydrolase for the one-step synthesis of alkyl glycosides with more than one monosaccharide unit.
- Full Text:
- Date Issued: 2020
- Authors: Mafa, Mpho S , Dirr, Heinrich , Malgas, Samkelo , Krause, Rui W M , Pletschke, Brett I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193976 , vital:45412 , xlink:href="https://doi.org/10.3390/molecules25030746"
- Description: An exoglucanase (Exg-D) from the glycoside hydrolase family 5 subfamily 38 (GH5_38) was heterologously expressed and structurally and biochemically characterised at a molecular level for its application in alkyl glycoside synthesis. The purified Exg-D existed in both dimeric and monomeric forms in solution, which showed highest activity on mixed-linked β-glucan (88.0 and 86.7 U/mg protein, respectively) and lichenin (24.5 and 23.7 U/mg protein, respectively). They displayed a broad optimum pH range from 5.5 to 7 and a temperature optimum from 40 to 60 °C. Kinetic studies demonstrated that Exg-D had a higher affinity towards β-glucan, with a Km of 7.9 mg/mL and a kcat of 117.2 s−1, compared to lichenin which had a Km of 21.5 mg/mL and a kcat of 70.0 s−1. The circular dichroism profile of Exg-D showed that its secondary structure consisted of 11% α-helices, 36% β-strands and 53% coils. Exg-D performed transglycosylation using p-nitrophenyl cellobioside as a glycosyl donor and several primary alcohols as acceptors to produce methyl-, ethyl- and propyl-cellobiosides. These products were identified and quantified via thin-layer chromatography (TLC) and liquid chromatography–mass spectrometry (LC-MS). We concluded that Exg-D is a novel and promising oligomeric glycoside hydrolase for the one-step synthesis of alkyl glycosides with more than one monosaccharide unit.
- Full Text:
- Date Issued: 2020
Terminaliamide, a new ceramide and other phytoconstituents from the roots of Terminalia mantaly H. Perrier and their biological activities
- Mbosso, Emmanuel, Siwe-Noundou, Xavier, Fannang, Simon, Song, Achille M, Assob, Jules C N, Hoppe, Heinrich, Krause, Rui W M
- Authors: Mbosso, Emmanuel , Siwe-Noundou, Xavier , Fannang, Simon , Song, Achille M , Assob, Jules C N , Hoppe, Heinrich , Krause, Rui W M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191779 , vital:45163 , xlink:href="https://doi.org/10.1080/14786419.2019.1647425"
- Description: Terminaliamide (1), a new ceramide was isolated from the roots of Terminalia mantaly H. Perrier (Combretaceae) along with 4 known compounds (2–5). The structures of the compounds were elucidated using 1D and 2D NMR spectroscopy analysis and mass spectrometry. Compound 1 exhibited moderated antibacterial activity towards Staphylococcus aureus with MIC value of 62.5 μg/mL. The crude MeOH extract (TMr) highly reduced Plasmodium falciparum growth with an IC50 value of 10.11 μg/mL, while hexane fraction (F1) highly reduced Trypanosoma brucei brucei growth with an IC50 value of 5.60 µg/mL. All tested samples presented little or no in vitro cytotoxicity on HeLa cell line. The present work confirms that T. mantaly is medicinally important and may be used effectively as an antimicrobial, an antiplasmodial and an antitrypanosomial with promising therapeutic index.
- Full Text:
- Date Issued: 2021
- Authors: Mbosso, Emmanuel , Siwe-Noundou, Xavier , Fannang, Simon , Song, Achille M , Assob, Jules C N , Hoppe, Heinrich , Krause, Rui W M
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191779 , vital:45163 , xlink:href="https://doi.org/10.1080/14786419.2019.1647425"
- Description: Terminaliamide (1), a new ceramide was isolated from the roots of Terminalia mantaly H. Perrier (Combretaceae) along with 4 known compounds (2–5). The structures of the compounds were elucidated using 1D and 2D NMR spectroscopy analysis and mass spectrometry. Compound 1 exhibited moderated antibacterial activity towards Staphylococcus aureus with MIC value of 62.5 μg/mL. The crude MeOH extract (TMr) highly reduced Plasmodium falciparum growth with an IC50 value of 10.11 μg/mL, while hexane fraction (F1) highly reduced Trypanosoma brucei brucei growth with an IC50 value of 5.60 µg/mL. All tested samples presented little or no in vitro cytotoxicity on HeLa cell line. The present work confirms that T. mantaly is medicinally important and may be used effectively as an antimicrobial, an antiplasmodial and an antitrypanosomial with promising therapeutic index.
- Full Text:
- Date Issued: 2021
Preparation and characterization of isoniazid-loaded crude soybean lecithin liposomes
- Nkanga, Christian I, Isaacs, Michelle, Noundou, Xavier S, Krause, Rui W M, Walker, Roderick B
- Authors: Nkanga, Christian I , Isaacs, Michelle , Noundou, Xavier S , Krause, Rui W M , Walker, Roderick B
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125654 , vital:35804 , https://doi.org/10.1016/j.ijpharm.2017.04.074
- Description: Unexpected substituent-dependent regioselectivty challenges in the synthesis of C-benzylated (N-arylcarbamoyl)phosphonate esters have been resolved. The C-benzylated N-furfurylcarbamoyl derivative showed low micromolar PfLDH inhibition, while one of the C-benzylated N-arylcarbamoyl analogues was active against Nagana Trypanosoma brucei parasites which are responsible for African trypanosomiasis in cattle.
- Full Text:
- Date Issued: 2017
- Authors: Nkanga, Christian I , Isaacs, Michelle , Noundou, Xavier S , Krause, Rui W M , Walker, Roderick B
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125654 , vital:35804 , https://doi.org/10.1016/j.ijpharm.2017.04.074
- Description: Unexpected substituent-dependent regioselectivty challenges in the synthesis of C-benzylated (N-arylcarbamoyl)phosphonate esters have been resolved. The C-benzylated N-furfurylcarbamoyl derivative showed low micromolar PfLDH inhibition, while one of the C-benzylated N-arylcarbamoyl analogues was active against Nagana Trypanosoma brucei parasites which are responsible for African trypanosomiasis in cattle.
- Full Text:
- Date Issued: 2017
Antiplasmodial Activity of the n-Hexane Extract from Pleurotus ostreatus (Jacq. ex. Fr) P. Kumm
- Afieroho, Ozadheoghene E, Siwe-Noundou, Xavier, Onyia, Chiazor P, Festus, Osamuyi H, Chukwu, Elizabeth C, Adedokun, Olutayo M, Isaacs, Michelle, Hoppe, Heinrich, Krause, Rui W M, Abo, Kio A
- Authors: Afieroho, Ozadheoghene E , Siwe-Noundou, Xavier , Onyia, Chiazor P , Festus, Osamuyi H , Chukwu, Elizabeth C , Adedokun, Olutayo M , Isaacs, Michelle , Hoppe, Heinrich , Krause, Rui W M , Abo, Kio A
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/194981 , vital:45516 , xlink:href="https://doi.org/10.4274/tjps.18894"
- Description: Objectives: Several mushrooms species have been reported to be nematophagous and antiprotozoan. This study reported the antiplasmodial and cytotoxic properties of the n-hexane extract from the edible mushroom Pleurotus ostreatus and the isolation of a sterol from the extract. Materials and Methods: Antiplasmodial and cytotoxicity assays were done in vitro using the plasmodium lactate dehydrogenase assay and human HeLa cervical cell lines, respectively. The structure of the isolated compound from the n-hexane extract was elucidated using spectroscopic techniques. Results: The n-hexane extract (yield: 0.93% w/w) showed dose dependent antiplasmodial activity with the trend in parasite inhibition of: chloroquine (IC50=0.016 μg/mL) > n-hexane extract (IC50=25.18 μg/mL). It also showed mild cytotoxicity (IC50>100 μg/mL; selectivity index >4) compared to the reference drug emetine (IC50=0.013 μg/mL). The known sterol, ergostan-5,7,22-trien-3-ol, was isolated and characterized from the extract. Conclusion: This study reporting for the first time the antiplasmodial activity of P. ostreatus revealed its nutraceutical potential in the management of malaria.
- Full Text:
- Date Issued: 2019
- Authors: Afieroho, Ozadheoghene E , Siwe-Noundou, Xavier , Onyia, Chiazor P , Festus, Osamuyi H , Chukwu, Elizabeth C , Adedokun, Olutayo M , Isaacs, Michelle , Hoppe, Heinrich , Krause, Rui W M , Abo, Kio A
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/194981 , vital:45516 , xlink:href="https://doi.org/10.4274/tjps.18894"
- Description: Objectives: Several mushrooms species have been reported to be nematophagous and antiprotozoan. This study reported the antiplasmodial and cytotoxic properties of the n-hexane extract from the edible mushroom Pleurotus ostreatus and the isolation of a sterol from the extract. Materials and Methods: Antiplasmodial and cytotoxicity assays were done in vitro using the plasmodium lactate dehydrogenase assay and human HeLa cervical cell lines, respectively. The structure of the isolated compound from the n-hexane extract was elucidated using spectroscopic techniques. Results: The n-hexane extract (yield: 0.93% w/w) showed dose dependent antiplasmodial activity with the trend in parasite inhibition of: chloroquine (IC50=0.016 μg/mL) > n-hexane extract (IC50=25.18 μg/mL). It also showed mild cytotoxicity (IC50>100 μg/mL; selectivity index >4) compared to the reference drug emetine (IC50=0.013 μg/mL). The known sterol, ergostan-5,7,22-trien-3-ol, was isolated and characterized from the extract. Conclusion: This study reporting for the first time the antiplasmodial activity of P. ostreatus revealed its nutraceutical potential in the management of malaria.
- Full Text:
- Date Issued: 2019
In vitro antimalarial, antitrypanosomal and HIV-1 integrase inhibitory activities of two Cameroonian medicinal plants
- Fouokeng, Yannick, Feumo Feusso, H M, Mbosso Teinkela, Jean E, Siwe-Noundou, Xavier, Wintjens, René T, Isaacs, Michelle, Hoppe, Heinrich, Krause, Rui W M, Azébazé, Anatole G B, Vardamides, Juliette C
- Authors: Fouokeng, Yannick , Feumo Feusso, H M , Mbosso Teinkela, Jean E , Siwe-Noundou, Xavier , Wintjens, René T , Isaacs, Michelle , Hoppe, Heinrich , Krause, Rui W M , Azébazé, Anatole G B , Vardamides, Juliette C
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/195014 , vital:45519 , xlink:href="https://doi.org/10.1016/j.sajb.2018.10.008"
- Description: Antiplasmodial, antitrypanosomal and anti-HIV-1 activities of crude extracts, fractions and some isolated compounds from two Cameroonian medicinal plants: Antrocaryon klaineanum Pierre (Anacardiaceae) and Diospyros conocarpa Gürke ex K. Schum. (Ebenaceae) were assessed. The phytochemical studies led to the isolation of eight compounds (1–8) from Diospyros conocarpa and six compounds (6, 9–13) from Antrocaryon klaineanum. These compounds were identified as mangiferolic acid (1), 3β, 22(S)-dihydroxycycloart-24E-en-26-oic acid (2), lupeol (3), aridanin (4), betulin (5), betulinic acid (6), bergenin (7), D-quercitol(8), entilin C(9), entilin A(10), antrocarine A(11), 7R,20(S)-dihydroxy-4,24(28)-ergostadien-3-one(12) and stigmasterol glucoside (13). The criteria for activity were set as follows: an IC50 value more than 10 μg/mL for crude extracts and more than 1 μg/mL for pure compounds. The hexane/ethyl acetate (1:1) fraction of A.klaineanum root bark (AKERF1) and the hexane/ethyl acetate (1:1) fraction of A.klaineanum trunk bark (AKETF1) presented the strongest antiplasmodial activities with IC50 values of 0.4 and 4.4 μg/mL, respectively. Aridanin (4) and antrocarine A(11), as well as the crude extract of D.conocarpa roots (EDCR), AKERF1 and AKETF1 showed moderate trypanocidal effects. The crude extract of A.klaineanum root bark (AKER) and AKETF1 exhibited attractive activities on HIV-1 integrase with IC50 values of 1.96 and 24.04 μg/mL, respectively. The results provide baseline information on the use of A.klaineanum and D.conocarpa extracts, as well as certain components, as sources of new antiplasmodial, antitrypanosomal and anti-HIV drugs.
- Full Text:
- Date Issued: 2019
- Authors: Fouokeng, Yannick , Feumo Feusso, H M , Mbosso Teinkela, Jean E , Siwe-Noundou, Xavier , Wintjens, René T , Isaacs, Michelle , Hoppe, Heinrich , Krause, Rui W M , Azébazé, Anatole G B , Vardamides, Juliette C
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/195014 , vital:45519 , xlink:href="https://doi.org/10.1016/j.sajb.2018.10.008"
- Description: Antiplasmodial, antitrypanosomal and anti-HIV-1 activities of crude extracts, fractions and some isolated compounds from two Cameroonian medicinal plants: Antrocaryon klaineanum Pierre (Anacardiaceae) and Diospyros conocarpa Gürke ex K. Schum. (Ebenaceae) were assessed. The phytochemical studies led to the isolation of eight compounds (1–8) from Diospyros conocarpa and six compounds (6, 9–13) from Antrocaryon klaineanum. These compounds were identified as mangiferolic acid (1), 3β, 22(S)-dihydroxycycloart-24E-en-26-oic acid (2), lupeol (3), aridanin (4), betulin (5), betulinic acid (6), bergenin (7), D-quercitol(8), entilin C(9), entilin A(10), antrocarine A(11), 7R,20(S)-dihydroxy-4,24(28)-ergostadien-3-one(12) and stigmasterol glucoside (13). The criteria for activity were set as follows: an IC50 value more than 10 μg/mL for crude extracts and more than 1 μg/mL for pure compounds. The hexane/ethyl acetate (1:1) fraction of A.klaineanum root bark (AKERF1) and the hexane/ethyl acetate (1:1) fraction of A.klaineanum trunk bark (AKETF1) presented the strongest antiplasmodial activities with IC50 values of 0.4 and 4.4 μg/mL, respectively. Aridanin (4) and antrocarine A(11), as well as the crude extract of D.conocarpa roots (EDCR), AKERF1 and AKETF1 showed moderate trypanocidal effects. The crude extract of A.klaineanum root bark (AKER) and AKETF1 exhibited attractive activities on HIV-1 integrase with IC50 values of 1.96 and 24.04 μg/mL, respectively. The results provide baseline information on the use of A.klaineanum and D.conocarpa extracts, as well as certain components, as sources of new antiplasmodial, antitrypanosomal and anti-HIV drugs.
- Full Text:
- Date Issued: 2019
Synthesis and biological evaluation of bis-N2, N2′-(4-hydroxycoumarin-3-yl) ethylidene]-2, 3-dihydroxysuccinodihydrazides
- Manyeruke, Meloddy H, Tshiwawa, Thendamudzimu, Hoppe, Heinrich, Isaacs, Michelle, Seldon, Ronnett, Warner, Digby F, Krause, Rui W M, Kaye, Perry T
- Authors: Manyeruke, Meloddy H , Tshiwawa, Thendamudzimu , Hoppe, Heinrich , Isaacs, Michelle , Seldon, Ronnett , Warner, Digby F , Krause, Rui W M , Kaye, Perry T
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193430 , vital:45331 , xlink:href="https://doi.org/10.1016/j.bmcl.2019.126911"
- Description: A series of N2,N2′-bis[4-hydroxycoumarin-3-yl)ethylidene]-2,3-dihydroxysuccino-hydrazides, containing 4-hydroxycoumarin, hydrazine and tartaric acid moieties, have been prepared and examined for possible biological activity. Several of these compounds exhibit promising HIV-1 integrase inhibition (IC50 = 3.5 μM), and anti-T. brucei (32% viability) and anti-mycobacterial (Visual MIC90 = 15.63 μM) activity.
- Full Text:
- Date Issued: 2020
- Authors: Manyeruke, Meloddy H , Tshiwawa, Thendamudzimu , Hoppe, Heinrich , Isaacs, Michelle , Seldon, Ronnett , Warner, Digby F , Krause, Rui W M , Kaye, Perry T
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193430 , vital:45331 , xlink:href="https://doi.org/10.1016/j.bmcl.2019.126911"
- Description: A series of N2,N2′-bis[4-hydroxycoumarin-3-yl)ethylidene]-2,3-dihydroxysuccino-hydrazides, containing 4-hydroxycoumarin, hydrazine and tartaric acid moieties, have been prepared and examined for possible biological activity. Several of these compounds exhibit promising HIV-1 integrase inhibition (IC50 = 3.5 μM), and anti-T. brucei (32% viability) and anti-mycobacterial (Visual MIC90 = 15.63 μM) activity.
- Full Text:
- Date Issued: 2020
Anti-cancer and anti-trypanosomal properties of alkaloids from the root bark of Zanthoxylum leprieurii Guill and Perr
- Eze, Fabian I, Siwe-Noundou, Xavier, Isaacs, Michelle, Patala, Srivinas, Osadebe, Patience O, Krause, Rui W M
- Authors: Eze, Fabian I , Siwe-Noundou, Xavier , Isaacs, Michelle , Patala, Srivinas , Osadebe, Patience O , Krause, Rui W M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193352 , vital:45324 , xlink:href="http://dx.doi.org/10.4314/tjpr.v19i11.19"
- Description: Purpose: To isolate the anti-cancer and anti-trypanosomal principles of Zanthoxylum leprieurii, a medicinally versatile wild tropical plant used for managing tumours, African trypanosomiasis, and inflammation in southeastern Nigeria. Methods: The pure compounds were isolated using chromatographic methods. The structural elucidation of the pure compounds was based on their NMR (1D and 2D) and mass spectral data as well as chemical test results. Structure-activity relationships were based on the structural differences among the compounds. The cytotoxicity of the extracts and compounds (1, 2, 3, and 4) was evaluated in HeLa (human cervix adenocarcinoma) cell line while the trypanocidal activities were evaluated on Trypanosoma brucei brucei. Results: Two acridone alkaloids, 1-hydroxy-3-methoxy-10-methylacridin-9 (10H)-one, named fabiocinine (1), and 1-hydroxy-2,3-dimethoxy-10-methylacridin-9 (10H)-one (arborinine, 2), together with a furoquinoline alkaloid, skimmianine (3), and a chelerythrine derivative, 6-acetonyl-5,6-dihydrochelerythrine (4) were isolated from the root bark of Zanthoxylum leprieurii. Skimmianine (3) exhibited cytotoxicity and anti-trypanosomal IC50 of 12.8 and 13.2 µg/mL respectively (p less than 0.05). Compound (1) and arborinine (2) were selectively cytotoxic to HeLa cells with cytotoxicity IC50 of 28.49 and 62.71 µg/mL, respectively, while (4) did not show significant activity (p less than 0.05). Conclusion: Zanthoxylum leprieurii root bark contains cytotoxic and trypanocidal compounds, and is thus a potential source of anti-cancer and anti-trypanosomal leads.
- Full Text:
- Date Issued: 2020
- Authors: Eze, Fabian I , Siwe-Noundou, Xavier , Isaacs, Michelle , Patala, Srivinas , Osadebe, Patience O , Krause, Rui W M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193352 , vital:45324 , xlink:href="http://dx.doi.org/10.4314/tjpr.v19i11.19"
- Description: Purpose: To isolate the anti-cancer and anti-trypanosomal principles of Zanthoxylum leprieurii, a medicinally versatile wild tropical plant used for managing tumours, African trypanosomiasis, and inflammation in southeastern Nigeria. Methods: The pure compounds were isolated using chromatographic methods. The structural elucidation of the pure compounds was based on their NMR (1D and 2D) and mass spectral data as well as chemical test results. Structure-activity relationships were based on the structural differences among the compounds. The cytotoxicity of the extracts and compounds (1, 2, 3, and 4) was evaluated in HeLa (human cervix adenocarcinoma) cell line while the trypanocidal activities were evaluated on Trypanosoma brucei brucei. Results: Two acridone alkaloids, 1-hydroxy-3-methoxy-10-methylacridin-9 (10H)-one, named fabiocinine (1), and 1-hydroxy-2,3-dimethoxy-10-methylacridin-9 (10H)-one (arborinine, 2), together with a furoquinoline alkaloid, skimmianine (3), and a chelerythrine derivative, 6-acetonyl-5,6-dihydrochelerythrine (4) were isolated from the root bark of Zanthoxylum leprieurii. Skimmianine (3) exhibited cytotoxicity and anti-trypanosomal IC50 of 12.8 and 13.2 µg/mL respectively (p less than 0.05). Compound (1) and arborinine (2) were selectively cytotoxic to HeLa cells with cytotoxicity IC50 of 28.49 and 62.71 µg/mL, respectively, while (4) did not show significant activity (p less than 0.05). Conclusion: Zanthoxylum leprieurii root bark contains cytotoxic and trypanocidal compounds, and is thus a potential source of anti-cancer and anti-trypanosomal leads.
- Full Text:
- Date Issued: 2020
Synthesis and anti-parasitic activity of C-benzylated (N-arylcarbamoyl) alkylphosphonate esters
- Adeyemi, Christiana Modupe, Isaacs, Michelle, Mnkandhla, Dumisani, Krause, Rui W M, Klein, Rosalyn, Hoppe, Heinrich C, Lobb, Kevin A, Kaye, Perry T
- Authors: Adeyemi, Christiana Modupe , Isaacs, Michelle , Mnkandhla, Dumisani , Krause, Rui W M , Klein, Rosalyn , Hoppe, Heinrich C , Lobb, Kevin A , Kaye, Perry T
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125641 , vital:35803 , https://doi.org/10.1016/j.tet.2017.01.045
- Description: Unexpected substituent-dependent regioselectivty challenges in the synthesis of C-benzylated (N-arylcarbamoyl)phosphonate esters have been resolved. The C-benzylated N-furfurylcarbamoyl derivative showed low micromolar PfLDH inhibition, while one of the C-benzylated N-arylcarbamoyl analogues was active against Nagana Trypanosoma brucei parasites which are responsible for African trypanosomiasis in cattle.
- Full Text:
- Date Issued: 2017
- Authors: Adeyemi, Christiana Modupe , Isaacs, Michelle , Mnkandhla, Dumisani , Krause, Rui W M , Klein, Rosalyn , Hoppe, Heinrich C , Lobb, Kevin A , Kaye, Perry T
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125641 , vital:35803 , https://doi.org/10.1016/j.tet.2017.01.045
- Description: Unexpected substituent-dependent regioselectivty challenges in the synthesis of C-benzylated (N-arylcarbamoyl)phosphonate esters have been resolved. The C-benzylated N-furfurylcarbamoyl derivative showed low micromolar PfLDH inhibition, while one of the C-benzylated N-arylcarbamoyl analogues was active against Nagana Trypanosoma brucei parasites which are responsible for African trypanosomiasis in cattle.
- Full Text:
- Date Issued: 2017
Synthesis, antiplasmodial and antitrypanosomal evaluation of a series of novel 2-oxoquinoline-based thiosemicarbazone derivatives
- Darrell, Oliver T, Hulushe, Siyabonga T, Mtshare, Thanduxolo Elihle, Beteck, Richard M, Isaacs, Michelle, Laming, Dustin, Khanye, Setshaba D, Hoppe, Heinrich C, Krause, Rui W M
- Authors: Darrell, Oliver T , Hulushe, Siyabonga T , Mtshare, Thanduxolo Elihle , Beteck, Richard M , Isaacs, Michelle , Laming, Dustin , Khanye, Setshaba D , Hoppe, Heinrich C , Krause, Rui W M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123117 , vital:35407 , https://doi.org/10.17159/0379-4350/2018/v71a25
- Description: Herein a series of novel thiosemicarbazones (TSCs) derived from 2-oxoquinoline scaffold is reported, and the target compounds have been successfully synthesized and characterized using standard spectroscopic techniques. The in vitro biological activities of synthesized molecules were evaluated against Plasmodium falciparum malaria parasites (strain 3D7), Trypanosoma brucei brucei parasites (strain 427) and HeLa cells. All the compounds displayed modest or no activity at a concentration of 20 μM and percentage viability of >50 % was often observed. Except for compound 9o, none of the final compounds exhibited cytotoxic effects against HeLa cells at 20 μM.
- Full Text:
- Date Issued: 2018
- Authors: Darrell, Oliver T , Hulushe, Siyabonga T , Mtshare, Thanduxolo Elihle , Beteck, Richard M , Isaacs, Michelle , Laming, Dustin , Khanye, Setshaba D , Hoppe, Heinrich C , Krause, Rui W M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123117 , vital:35407 , https://doi.org/10.17159/0379-4350/2018/v71a25
- Description: Herein a series of novel thiosemicarbazones (TSCs) derived from 2-oxoquinoline scaffold is reported, and the target compounds have been successfully synthesized and characterized using standard spectroscopic techniques. The in vitro biological activities of synthesized molecules were evaluated against Plasmodium falciparum malaria parasites (strain 3D7), Trypanosoma brucei brucei parasites (strain 427) and HeLa cells. All the compounds displayed modest or no activity at a concentration of 20 μM and percentage viability of >50 % was often observed. Except for compound 9o, none of the final compounds exhibited cytotoxic effects against HeLa cells at 20 μM.
- Full Text:
- Date Issued: 2018
In vitro antimalarial, antitrypanosomal and HIV-1 integrase inhibitory activities of two Cameroonian medicinal plants: Antrocaryon klaineanum (Anacardiaceae) and Diospyros conocarpa (Ebenaceae)
- Fouokeng, Y, Feusso, H M Feumo, Noundou, Xavier S, Krause, Rui W M, Teinkela, Jean E Mb, Wintjens, R, Hoppe, Heinrich C, Azebaze, Anatole G B, Vardamides, Juliette C, Isaacs, Michelle
- Authors: Fouokeng, Y , Feusso, H M Feumo , Noundou, Xavier S , Krause, Rui W M , Teinkela, Jean E Mb , Wintjens, R , Hoppe, Heinrich C , Azebaze, Anatole G B , Vardamides, Juliette C , Isaacs, Michelle
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126653 , vital:35908 , https://doi.org/10.1016/j.sajb.2018.10.008
- Description: Antiplasmodial, antitrypanosomal and anti-HIV-1 activities of crude extracts, fractions and some isolated compounds from two Cameroonian medicinal plants: Antrocaryon klaineanum Pierre (Anacardiaceae) and Diospyros conocarpa Gürke ex K. Schum. (Ebenaceae) were assessed. The phytochemical studies led to the isolation of eight compounds (1–8) from Diospyros conocarpa and six compounds (6, 9–13) from Antrocaryon klaineanum. These compounds were identified as mangiferolic acid (1), 3β, 22(S)-dihydroxycycloart-24E-en-26-oic acid (2), lupeol (3), aridanin (4), betulin (5), betulinic acid (6), bergenin (7), D-quercitol(8), entilin C(9), entilin A(10), antrocarine A(11), 7R,20(S)-dihydroxy-4,24(28)-ergostadien-3-one(12) and stigmasterol glucoside (13). The criteria for activity were set as follows: an IC50 value
- Full Text:
- Date Issued: 2018
- Authors: Fouokeng, Y , Feusso, H M Feumo , Noundou, Xavier S , Krause, Rui W M , Teinkela, Jean E Mb , Wintjens, R , Hoppe, Heinrich C , Azebaze, Anatole G B , Vardamides, Juliette C , Isaacs, Michelle
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126653 , vital:35908 , https://doi.org/10.1016/j.sajb.2018.10.008
- Description: Antiplasmodial, antitrypanosomal and anti-HIV-1 activities of crude extracts, fractions and some isolated compounds from two Cameroonian medicinal plants: Antrocaryon klaineanum Pierre (Anacardiaceae) and Diospyros conocarpa Gürke ex K. Schum. (Ebenaceae) were assessed. The phytochemical studies led to the isolation of eight compounds (1–8) from Diospyros conocarpa and six compounds (6, 9–13) from Antrocaryon klaineanum. These compounds were identified as mangiferolic acid (1), 3β, 22(S)-dihydroxycycloart-24E-en-26-oic acid (2), lupeol (3), aridanin (4), betulin (5), betulinic acid (6), bergenin (7), D-quercitol(8), entilin C(9), entilin A(10), antrocarine A(11), 7R,20(S)-dihydroxy-4,24(28)-ergostadien-3-one(12) and stigmasterol glucoside (13). The criteria for activity were set as follows: an IC50 value
- Full Text:
- Date Issued: 2018
Biological activities of plant extracts from Ficus elastica and Selaginella vogelli: an antimalarial, antitrypanosomal and cytotoxity evaluation
- Meyer, Franck, Isaacs, Michelle, Noundou, Xavier S, Krause, Rui W M, Teinkela, J E M, Hoppe, Heinrich C, Mpondo, Albert E M, Azebaze, Anatole G B, Nguemfo, Edwige L, Wintjens, Rene
- Authors: Meyer, Franck , Isaacs, Michelle , Noundou, Xavier S , Krause, Rui W M , Teinkela, J E M , Hoppe, Heinrich C , Mpondo, Albert E M , Azebaze, Anatole G B , Nguemfo, Edwige L , Wintjens, Rene
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126142 , vital:35853 , https://doi.org/10.1016/j.sjbs.2017.07.002
- Description: The cytotoxic, antiplasmodial, and antitrypanosomal activities of two medicinal plants traditionally used in Cameroon were evaluated. Wood of Ficus elastica Roxb. ex Hornem. aerial roots (Moraceae) and Selaginella vogelii Spring (Selaginellaceae) leaves were collected from two different sites in Cameroon. In vitro cell-growth inhibition activities were assessed on methanol extract of plant materials against Plasmodium falciparum strain 3D7 and Trypanosoma brucei brucei, as well as against HeLa human cervical carcinoma cells. Criteria for activity were an IC50 value 10 μg/mL. The extract of S. vogelii did not significantly reduce the viability of P. falciparum at a concentration of 25 μg/mL but dramatically affected the trypanosome growth with an IC50 of 2.4 μg/mL. In contrast, at the same concentration, the extract of F. elastica exhibited plasmodiacidal activity (IC50 value of 9.5 μg/mL) and trypanocidal (IC50 value of 0.9 μg/mL) activity. Both extracts presented low cytotoxic effects on HeLa cancer cell line. These results indicate that the selected medicinal plants could be further investigated for identifying compounds that may be responsible for the observed activities and that may represent new leads in parasitical drug discovery.
- Full Text:
- Date Issued: 2018
- Authors: Meyer, Franck , Isaacs, Michelle , Noundou, Xavier S , Krause, Rui W M , Teinkela, J E M , Hoppe, Heinrich C , Mpondo, Albert E M , Azebaze, Anatole G B , Nguemfo, Edwige L , Wintjens, Rene
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126142 , vital:35853 , https://doi.org/10.1016/j.sjbs.2017.07.002
- Description: The cytotoxic, antiplasmodial, and antitrypanosomal activities of two medicinal plants traditionally used in Cameroon were evaluated. Wood of Ficus elastica Roxb. ex Hornem. aerial roots (Moraceae) and Selaginella vogelii Spring (Selaginellaceae) leaves were collected from two different sites in Cameroon. In vitro cell-growth inhibition activities were assessed on methanol extract of plant materials against Plasmodium falciparum strain 3D7 and Trypanosoma brucei brucei, as well as against HeLa human cervical carcinoma cells. Criteria for activity were an IC50 value 10 μg/mL. The extract of S. vogelii did not significantly reduce the viability of P. falciparum at a concentration of 25 μg/mL but dramatically affected the trypanosome growth with an IC50 of 2.4 μg/mL. In contrast, at the same concentration, the extract of F. elastica exhibited plasmodiacidal activity (IC50 value of 9.5 μg/mL) and trypanocidal (IC50 value of 0.9 μg/mL) activity. Both extracts presented low cytotoxic effects on HeLa cancer cell line. These results indicate that the selected medicinal plants could be further investigated for identifying compounds that may be responsible for the observed activities and that may represent new leads in parasitical drug discovery.
- Full Text:
- Date Issued: 2018
Biological activity of plant extracts and isolated compounds from Alchornea laxiflora: Anti-HIV, antibacterial and cytotoxicity evaluation
- Ndinteh, Derek T, Olivier, D K, Noundou, Xavier S, Krause, Rui W M, Mnkandhla, D, Isaacs, Michelle, Hoppe, Heinrich C, Muganza, F M, Mbafor, J T, Van Vuuren, S F, Patnala, S
- Authors: Ndinteh, Derek T , Olivier, D K , Noundou, Xavier S , Krause, Rui W M , Mnkandhla, D , Isaacs, Michelle , Hoppe, Heinrich C , Muganza, F M , Mbafor, J T , Van Vuuren, S F , Patnala, S
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126634 , vital:35907 , https://doi.org/10.1016/j.sajb.2018.08.010
- Description: This study was designed to assess the cytotoxicity, anti-HIV and antibacterial efficacy of various solvent extracts of roots, stem and leaves of Alchornea laxiflora, as well as five compounds isolated from its methanolic stem extract viz.; ellagic acid (1); 3-O-methyl-ellagic acid (2), 3-O-β-d-glucopyranosyl-β-sitosterol (3), 3-O-acetyl-oleanolic acid (4) and 3-O-acetyl-ursolic acid (5). The tested crude extracts were prepared from several solvent polarities including: hexane (Hex), chloroform (CHCl3), ethyl acetate (EtOAc), ethanol (EtOH), methanol (MeOH) and water (H2O). The anti-HIV properties were assessed on HIV-1 subtype C integrase while the cytotoxicity was tested against Hela cells. The antibacterial activity was studied on a panel of pathogens including gastrointestinal, skin, respiratory and urinary-tract infection causing Gram positive bacteria viz.; Bacillus cereus (ATCC 11778), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 25923) and Staphylococcus saprophyticus (ATCC 15305)] and Gram-negative bacteria, i.e., Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13883), Moraxella catarrhalis (ATCC 23246). All the tested samples were determined to be non-toxic due to the low inhibitions observed. The most potent anti-HIV activity was observed for the methanolic extract of A. laxiflora root (ALR4) with an IC50 value of 0.21 ng/ml, which was more active than chicoric acid used as reference drug (6.82 nM). Roots, stem and leaves of A. laxiflora extracts exhibited antibacterial activities against most of the Gram-positive bacteria with the minimum inhibitory concentrations (MIC) ranging between 50 and 63 μg/ml. Compounds 1–5 displayed antibacterial activities against S. saprophyticus with MIC values as low as 4 μg/ml. The results inferred from this study demonstrate the potential of A. laxiflora root as a source for new anti-HIV drugs and scientifically validate the traditional use of A. laxiflora in the treatment of gastrointestinal, skin, respiratory and urinary tract related infections. These results reaffirm the ethnopharmacological significance of African traditional medicines.
- Full Text:
- Date Issued: 2018
- Authors: Ndinteh, Derek T , Olivier, D K , Noundou, Xavier S , Krause, Rui W M , Mnkandhla, D , Isaacs, Michelle , Hoppe, Heinrich C , Muganza, F M , Mbafor, J T , Van Vuuren, S F , Patnala, S
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126634 , vital:35907 , https://doi.org/10.1016/j.sajb.2018.08.010
- Description: This study was designed to assess the cytotoxicity, anti-HIV and antibacterial efficacy of various solvent extracts of roots, stem and leaves of Alchornea laxiflora, as well as five compounds isolated from its methanolic stem extract viz.; ellagic acid (1); 3-O-methyl-ellagic acid (2), 3-O-β-d-glucopyranosyl-β-sitosterol (3), 3-O-acetyl-oleanolic acid (4) and 3-O-acetyl-ursolic acid (5). The tested crude extracts were prepared from several solvent polarities including: hexane (Hex), chloroform (CHCl3), ethyl acetate (EtOAc), ethanol (EtOH), methanol (MeOH) and water (H2O). The anti-HIV properties were assessed on HIV-1 subtype C integrase while the cytotoxicity was tested against Hela cells. The antibacterial activity was studied on a panel of pathogens including gastrointestinal, skin, respiratory and urinary-tract infection causing Gram positive bacteria viz.; Bacillus cereus (ATCC 11778), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 25923) and Staphylococcus saprophyticus (ATCC 15305)] and Gram-negative bacteria, i.e., Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13883), Moraxella catarrhalis (ATCC 23246). All the tested samples were determined to be non-toxic due to the low inhibitions observed. The most potent anti-HIV activity was observed for the methanolic extract of A. laxiflora root (ALR4) with an IC50 value of 0.21 ng/ml, which was more active than chicoric acid used as reference drug (6.82 nM). Roots, stem and leaves of A. laxiflora extracts exhibited antibacterial activities against most of the Gram-positive bacteria with the minimum inhibitory concentrations (MIC) ranging between 50 and 63 μg/ml. Compounds 1–5 displayed antibacterial activities against S. saprophyticus with MIC values as low as 4 μg/ml. The results inferred from this study demonstrate the potential of A. laxiflora root as a source for new anti-HIV drugs and scientifically validate the traditional use of A. laxiflora in the treatment of gastrointestinal, skin, respiratory and urinary tract related infections. These results reaffirm the ethnopharmacological significance of African traditional medicines.
- Full Text:
- Date Issued: 2018
Anti-HIV-1 integrase potency of methylgallate from Alchornea cordifolia using in vitro and in silico approaches:
- Noundou, Xavier S, Musyoka, Thommas M, Moses, Vuyani, Ndinteh, Derek T, Mnkandhla, Dumisani, Hoppe, Heinrich C, Tastan Bishop, Özlem, Krause, Rui W M
- Authors: Noundou, Xavier S , Musyoka, Thommas M , Moses, Vuyani , Ndinteh, Derek T , Mnkandhla, Dumisani , Hoppe, Heinrich C , Tastan Bishop, Özlem , Krause, Rui W M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/162975 , vital:41001 , https://0-doi.org.wam.seals.ac.za/10.1038/s41598-019-41403-x
- Description: According to the 2018 report of the United Nations Programme on HIV/AIDS (UNAIDS), acquired immune deficiency syndrome (AIDS), a disease caused by the human immunodeficiency virus (HIV), remains a significant public health problem. The non-existence of a cure or effective vaccine for the disease and the associated emergence of resistant viral strains imply an urgent need for the discovery of novel anti-HIV drug candidates. The current study aimed to identify potential anti-retroviral compounds from Alchornea cordifolia.
- Full Text:
- Date Issued: 2019
- Authors: Noundou, Xavier S , Musyoka, Thommas M , Moses, Vuyani , Ndinteh, Derek T , Mnkandhla, Dumisani , Hoppe, Heinrich C , Tastan Bishop, Özlem , Krause, Rui W M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/162975 , vital:41001 , https://0-doi.org.wam.seals.ac.za/10.1038/s41598-019-41403-x
- Description: According to the 2018 report of the United Nations Programme on HIV/AIDS (UNAIDS), acquired immune deficiency syndrome (AIDS), a disease caused by the human immunodeficiency virus (HIV), remains a significant public health problem. The non-existence of a cure or effective vaccine for the disease and the associated emergence of resistant viral strains imply an urgent need for the discovery of novel anti-HIV drug candidates. The current study aimed to identify potential anti-retroviral compounds from Alchornea cordifolia.
- Full Text:
- Date Issued: 2019
Ethnobotanical survey, phytoconstituents and antibacterial investigation of Rapanea melanophloeos (L.) Mez. bark, fruit and leaf extracts
- Lukhele, Thabile, Olivier, Denise, Tata, Charlotte, Ikhile, Monisola I, Krause, Rui W M, van Vuuren, Sandy, Ndineh, Derek T
- Authors: Lukhele, Thabile , Olivier, Denise , Tata, Charlotte , Ikhile, Monisola I , Krause, Rui W M , van Vuuren, Sandy , Ndineh, Derek T
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191791 , vital:45164 , xlink:href="https://doi.org/10.1515/psr-2020-0143"
- Description: Rapanea melanophloeos is traditionally used in South Africa in the treatment of ailments of the skin, pulmonary and gastro intestinal tract. This study was aimed at giving an overview of these traditional uses and comparing the phytochemicals and antibacterial activities of various crude extracts of the leaves, fruits and bark in order to validate these uses. The three plant parts were extracted using petroleum ether (PE), ethyl acetate (EtOAc), methanol (MeOH) and water. Various phytochemicals were compared using TLC, while alcohol precipitable solids (APS), non-polar terpenes and amino acids were analysed by GC-MS. Antibacterial activity was determined against three Gram-positive and three Gram-negative strains by microdilution assays. Caryophyllene oxides, α-cadinol and (−)-spathulenol were identified in the PE extracts. All nine essential amino acids were present in fruit extracts in significantly higher levels than in the leaves and bark; 255.1, 23.4 and 21.3 mg/g respectively. Most of the extracts showed good antibacterial activity, especially against the Gram-positive pathogens (MIC of ≤1 mg/mL), the EtOAc extracts exhibited the best activity with the fruit having an MIC values of 0.1 ± 0.2 mg/mL against Staphylococcus epidermidis and Enterococcus faecalis, 0.05 mg/mL against Bacillus cereus. Results from this study validate the ethnomedicinal uses of R. melanophloeos extracts for ailments of bacterial etiology. The plant had a rich supply of secondary metabolites, APS and amino acids and TLC and antibacterial activities of the extracts showed slight variations in chemical composition due to geographic distribution.
- Full Text:
- Date Issued: 2021
- Authors: Lukhele, Thabile , Olivier, Denise , Tata, Charlotte , Ikhile, Monisola I , Krause, Rui W M , van Vuuren, Sandy , Ndineh, Derek T
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191791 , vital:45164 , xlink:href="https://doi.org/10.1515/psr-2020-0143"
- Description: Rapanea melanophloeos is traditionally used in South Africa in the treatment of ailments of the skin, pulmonary and gastro intestinal tract. This study was aimed at giving an overview of these traditional uses and comparing the phytochemicals and antibacterial activities of various crude extracts of the leaves, fruits and bark in order to validate these uses. The three plant parts were extracted using petroleum ether (PE), ethyl acetate (EtOAc), methanol (MeOH) and water. Various phytochemicals were compared using TLC, while alcohol precipitable solids (APS), non-polar terpenes and amino acids were analysed by GC-MS. Antibacterial activity was determined against three Gram-positive and three Gram-negative strains by microdilution assays. Caryophyllene oxides, α-cadinol and (−)-spathulenol were identified in the PE extracts. All nine essential amino acids were present in fruit extracts in significantly higher levels than in the leaves and bark; 255.1, 23.4 and 21.3 mg/g respectively. Most of the extracts showed good antibacterial activity, especially against the Gram-positive pathogens (MIC of ≤1 mg/mL), the EtOAc extracts exhibited the best activity with the fruit having an MIC values of 0.1 ± 0.2 mg/mL against Staphylococcus epidermidis and Enterococcus faecalis, 0.05 mg/mL against Bacillus cereus. Results from this study validate the ethnomedicinal uses of R. melanophloeos extracts for ailments of bacterial etiology. The plant had a rich supply of secondary metabolites, APS and amino acids and TLC and antibacterial activities of the extracts showed slight variations in chemical composition due to geographic distribution.
- Full Text:
- Date Issued: 2021
Review of the Traditional Uses, Phytochemistry, and Pharmacological Activities of Rhoicissus Species (Vitaceae)
- Dube, Nondumiso, Siwe-Noundou, Xavier, Krause, Rui W M, Kemboi, Douglas, Tembu, Vuyelwa J, Manicum, Amanda-Lee
- Authors: Dube, Nondumiso , Siwe-Noundou, Xavier , Krause, Rui W M , Kemboi, Douglas , Tembu, Vuyelwa J , Manicum, Amanda-Lee
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191769 , vital:45162 , xlink:href="https://doi.org/10.3390/molecules26082306"
- Description: Species within the genus Rhoicissus (Vitaceae) are commonly used in South African traditional medicine. The current review discusses the occurrence, distribution, traditional uses, phytochemistry, and pharmacological properties of Rhoicissus species covering the period 1981–2020. The data reported were systematically collected, read, and analysed from scientific electronic databases including Scopus, Scifinder, Pubmed, and Google Scholar. Reported evidence indicates that species in this genus are used for the treatment of gastrointestinal complaints, sexually transmitted infections (STIs), and infertility, as well as to tone the uterus during pregnancy and to facilitate delivery. Pharmacological studies have further shown that members of the Rhoicissus genus display antidiabetic, uterotonic, ascaricidal, hepatoprotective, antioxidant, antimicrobial, anticancer, and anti-inflammatory properties. They are linked to the presence of bioactive compounds isolated from the genus. Hence, Rhoicissus species can potentially be an alternative therapeutic strategy to treat diseases and develop safer and more potent drugs to combat diseases. Plant species of this genus have valuable medicinal benefits due to their significant pharmacological potential. However, scientific investigation and information of the therapeutic potential of Rhoicissus remain limited as most of the species in the genus have not been fully exploited. Therefore, there is a need for further investigations to exploit the therapeutic potential of the genus Rhoicissus. Future studies should evaluate the phytochemical, pharmacological, and toxicological activities, as well as the mode of action, of Rhoicissus crude extracts and secondary compounds isolated from the species.
- Full Text:
- Date Issued: 2021
- Authors: Dube, Nondumiso , Siwe-Noundou, Xavier , Krause, Rui W M , Kemboi, Douglas , Tembu, Vuyelwa J , Manicum, Amanda-Lee
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191769 , vital:45162 , xlink:href="https://doi.org/10.3390/molecules26082306"
- Description: Species within the genus Rhoicissus (Vitaceae) are commonly used in South African traditional medicine. The current review discusses the occurrence, distribution, traditional uses, phytochemistry, and pharmacological properties of Rhoicissus species covering the period 1981–2020. The data reported were systematically collected, read, and analysed from scientific electronic databases including Scopus, Scifinder, Pubmed, and Google Scholar. Reported evidence indicates that species in this genus are used for the treatment of gastrointestinal complaints, sexually transmitted infections (STIs), and infertility, as well as to tone the uterus during pregnancy and to facilitate delivery. Pharmacological studies have further shown that members of the Rhoicissus genus display antidiabetic, uterotonic, ascaricidal, hepatoprotective, antioxidant, antimicrobial, anticancer, and anti-inflammatory properties. They are linked to the presence of bioactive compounds isolated from the genus. Hence, Rhoicissus species can potentially be an alternative therapeutic strategy to treat diseases and develop safer and more potent drugs to combat diseases. Plant species of this genus have valuable medicinal benefits due to their significant pharmacological potential. However, scientific investigation and information of the therapeutic potential of Rhoicissus remain limited as most of the species in the genus have not been fully exploited. Therefore, there is a need for further investigations to exploit the therapeutic potential of the genus Rhoicissus. Future studies should evaluate the phytochemical, pharmacological, and toxicological activities, as well as the mode of action, of Rhoicissus crude extracts and secondary compounds isolated from the species.
- Full Text:
- Date Issued: 2021
Flavonoids from the Genus Euphorbia
- Magozwi, Douglas K, Dinala, Mmabatho, Mokwana, Nthabiseng, Siwe-Noundou, Xavier, Krause, Rui W M, Sonopo, Molahleli, McGaw, Lyndy J, Augustyn, Wilma A, Tembu, Vuyelwa J
- Authors: Magozwi, Douglas K , Dinala, Mmabatho , Mokwana, Nthabiseng , Siwe-Noundou, Xavier , Krause, Rui W M , Sonopo, Molahleli , McGaw, Lyndy J , Augustyn, Wilma A , Tembu, Vuyelwa J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191736 , vital:45159 , xlink:href="https://doi.org/10.3390/ph14050428"
- Description: Plants of the genus Euphorbia are widely distributed across temperate, tropical and subtropical regions of South America, Asia and Africa with established Ayurvedic, Chinese and Malay ethnomedical records. The present review reports the isolation, occurrence, phytochemistry, biological properties, therapeutic potential and structure–activity relationship of Euphorbia flavonoids for the period covering 2000–2020, while identifying potential areas for future studies aimed at development of new therapeutic agents from these plants. The findings suggest that the extracts and isolated flavonoids possess anticancer, antiproliferative, antimalarial, antibacterial, anti-venom, anti-inflammatory, anti-hepatitis and antioxidant properties and have different mechanisms of action against cancer cells. Of the investigated species, over 80 different types of flavonoids have been isolated to date. Most of the isolated flavonoids were flavonols and comprised simple O-substitution patterns, C-methylation and prenylation. Others had a glycoside, glycosidic linkages and a carbohydrate attached at either C-3 or C-7, and were designated as d-glucose, l-rhamnose or glucorhamnose. The structure–activity relationship studies showed that methylation of the hydroxyl groups on C-3 or C-7 reduces the activities while glycosylation loses the activity and that the parent skeletal structure is essential in retaining the activity. These constituents can therefore offer potential alternative scaffolds towards development of new Euphorbia-based therapeutic agents.
- Full Text:
- Date Issued: 2021
- Authors: Magozwi, Douglas K , Dinala, Mmabatho , Mokwana, Nthabiseng , Siwe-Noundou, Xavier , Krause, Rui W M , Sonopo, Molahleli , McGaw, Lyndy J , Augustyn, Wilma A , Tembu, Vuyelwa J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191736 , vital:45159 , xlink:href="https://doi.org/10.3390/ph14050428"
- Description: Plants of the genus Euphorbia are widely distributed across temperate, tropical and subtropical regions of South America, Asia and Africa with established Ayurvedic, Chinese and Malay ethnomedical records. The present review reports the isolation, occurrence, phytochemistry, biological properties, therapeutic potential and structure–activity relationship of Euphorbia flavonoids for the period covering 2000–2020, while identifying potential areas for future studies aimed at development of new therapeutic agents from these plants. The findings suggest that the extracts and isolated flavonoids possess anticancer, antiproliferative, antimalarial, antibacterial, anti-venom, anti-inflammatory, anti-hepatitis and antioxidant properties and have different mechanisms of action against cancer cells. Of the investigated species, over 80 different types of flavonoids have been isolated to date. Most of the isolated flavonoids were flavonols and comprised simple O-substitution patterns, C-methylation and prenylation. Others had a glycoside, glycosidic linkages and a carbohydrate attached at either C-3 or C-7, and were designated as d-glucose, l-rhamnose or glucorhamnose. The structure–activity relationship studies showed that methylation of the hydroxyl groups on C-3 or C-7 reduces the activities while glycosylation loses the activity and that the parent skeletal structure is essential in retaining the activity. These constituents can therefore offer potential alternative scaffolds towards development of new Euphorbia-based therapeutic agents.
- Full Text:
- Date Issued: 2021
5-Fu inclusion complex capped gold nanoparticles for breast cancer therapy
- Lakkakula, Jaya R, Krause, Rui W M, Divakaran, Deepika, Barage, Sagar, Srivastava, Rohit
- Authors: Lakkakula, Jaya R , Krause, Rui W M , Divakaran, Deepika , Barage, Sagar , Srivastava, Rohit
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191713 , vital:45150 , xlink:href="https://doi.org/10.1016/j.molliq.2021.117262"
- Description: We have attempted to prolong the circulation time and increase the solubility of 5-Fluorouracil by complexing it with cyclodextrin and then further conjugating onto the gold nanoparticle to form 5Fu ICAu. The 1H NMR and molecular docking studies suggested that 5-Fu was included within the 2HP-β-CD cavity and H-5 proton probably serves as the binding site for stabilization of the inclusion complex. The 5Fu-ICAu showed higher cell inhibition rate when studied on MDA-MB-231 and MCF-7 breast cancer cell lines due to the enhanced permeability and retention (EPR) effect by allowing the selective accumulation of nanoparticles at tumor site. This unique system can serve as a novel nanocarrier for delivery of hydrophobic drugs.
- Full Text:
- Date Issued: 2021
- Authors: Lakkakula, Jaya R , Krause, Rui W M , Divakaran, Deepika , Barage, Sagar , Srivastava, Rohit
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191713 , vital:45150 , xlink:href="https://doi.org/10.1016/j.molliq.2021.117262"
- Description: We have attempted to prolong the circulation time and increase the solubility of 5-Fluorouracil by complexing it with cyclodextrin and then further conjugating onto the gold nanoparticle to form 5Fu ICAu. The 1H NMR and molecular docking studies suggested that 5-Fu was included within the 2HP-β-CD cavity and H-5 proton probably serves as the binding site for stabilization of the inclusion complex. The 5Fu-ICAu showed higher cell inhibition rate when studied on MDA-MB-231 and MCF-7 breast cancer cell lines due to the enhanced permeability and retention (EPR) effect by allowing the selective accumulation of nanoparticles at tumor site. This unique system can serve as a novel nanocarrier for delivery of hydrophobic drugs.
- Full Text:
- Date Issued: 2021
In vitro cytotoxic effects of chemical constituents of Euphorbia grandicornis Blanc against breast cancer cells
- Kemboi, Douglas, Peter, Xolani, Langat, Moses K, Mhlanga, Richwell, Vukea, Nyeleti, de la Mare, Jo-Anne, Siwe-Noundou, Xavier, Krause, Rui W M, Tembu, Vuyelwa J
- Authors: Kemboi, Douglas , Peter, Xolani , Langat, Moses K , Mhlanga, Richwell , Vukea, Nyeleti , de la Mare, Jo-Anne , Siwe-Noundou, Xavier , Krause, Rui W M , Tembu, Vuyelwa J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191747 , vital:45160 , xlink:href="https://doi.org/10.1016/j.sciaf.2021.e01002"
- Description: Euphorbia grandicornis Blanc is widely utilized in traditional medicine for a variety of ailments including body pains associated with skin irritations, inflammation, and snake or scorpion bites. Compounds from E. grandicornis were characterized using spectroscopic techniques, NMR, IR, MS, and melting points and alongside the extracts were evaluated for in vitro anticancer activity against several cancer cell lines. The root extract afforded known, β-glutinol (1), β-amyrin (2), 24-methylenetirucalla-8-en-3β-ol (3), tirucalla-8,25-diene-3β,24R-diol (4), stigmasterol (5), sitosterol (6), and hexyl (E)-3-(4-hydroxy-3-methoxyphenyl)-2-propenoate (7) based on their NMR spectroscopic data for the first report in E. grandicornis. The extracts and isolated compounds were evaluated for anticancer activities against hormone receptor-positive breast cancer (MCF-7), triple-negative breast cancer (HCC70), and non-tumorigenic mammary epithelial (MCF-12A) cell lines. The CH2Cl2 extract exhibited potent, cytotoxicity against MCF-7, HCC70, and MCF-12A cells. The aerial extract exhibited IC50 values of 1.03, 0.301, and 1.68 µg/mL, and root extract displayed IC50 values of 0.83, 0.83 and 3.98 µg/mL against MCF-7, HCC70, and MCF-12A cells respectively. The root extract thus showed selectivity for the cancer cell lines over the non-cancerous control cell line (SI = 4.80). Hexyl (E)-3-(4-hydroxy-3-methoxyphenyl)-2-propenoate (7) showed significant activity with IC50 values of 23.41, 29.45 and 27.01 µM against MCF-7, HCC70 and MCF-12A cells respectively, suggesting non-specific cytotoxicity.
- Full Text:
- Date Issued: 2021
- Authors: Kemboi, Douglas , Peter, Xolani , Langat, Moses K , Mhlanga, Richwell , Vukea, Nyeleti , de la Mare, Jo-Anne , Siwe-Noundou, Xavier , Krause, Rui W M , Tembu, Vuyelwa J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/191747 , vital:45160 , xlink:href="https://doi.org/10.1016/j.sciaf.2021.e01002"
- Description: Euphorbia grandicornis Blanc is widely utilized in traditional medicine for a variety of ailments including body pains associated with skin irritations, inflammation, and snake or scorpion bites. Compounds from E. grandicornis were characterized using spectroscopic techniques, NMR, IR, MS, and melting points and alongside the extracts were evaluated for in vitro anticancer activity against several cancer cell lines. The root extract afforded known, β-glutinol (1), β-amyrin (2), 24-methylenetirucalla-8-en-3β-ol (3), tirucalla-8,25-diene-3β,24R-diol (4), stigmasterol (5), sitosterol (6), and hexyl (E)-3-(4-hydroxy-3-methoxyphenyl)-2-propenoate (7) based on their NMR spectroscopic data for the first report in E. grandicornis. The extracts and isolated compounds were evaluated for anticancer activities against hormone receptor-positive breast cancer (MCF-7), triple-negative breast cancer (HCC70), and non-tumorigenic mammary epithelial (MCF-12A) cell lines. The CH2Cl2 extract exhibited potent, cytotoxicity against MCF-7, HCC70, and MCF-12A cells. The aerial extract exhibited IC50 values of 1.03, 0.301, and 1.68 µg/mL, and root extract displayed IC50 values of 0.83, 0.83 and 3.98 µg/mL against MCF-7, HCC70, and MCF-12A cells respectively. The root extract thus showed selectivity for the cancer cell lines over the non-cancerous control cell line (SI = 4.80). Hexyl (E)-3-(4-hydroxy-3-methoxyphenyl)-2-propenoate (7) showed significant activity with IC50 values of 23.41, 29.45 and 27.01 µM against MCF-7, HCC70 and MCF-12A cells respectively, suggesting non-specific cytotoxicity.
- Full Text:
- Date Issued: 2021