@article{ChepkiruiOchiengSarkaretal.2020,
  author    = {Chepkirui, Carolyne and Ochieng, Purity J. and Sarkar, Biswajyoti and Hussain, Aabid and Pal, Chiranjib and Yang, Li Jun and Coghi, Paolo and Akala, Hoseah M. and Derese, Solomon and Ndakala, Albert and Heydenreich, Matthias and Wong, Vincent K. W. and Erdelyi, Mate and Yenesew, Abiy},
  title     = {Antiplasmodial and antileishmanial flavonoids from Mundulea sericea},
  series = {Fitoterapia},
  volume    = {149},
  journal   = {Fitoterapia},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0367-326X},
  doi       = {10.1016/j.fitote.2020.104796},
  pages     = {6},
  year      = {2020},
  abstract  = {Five known compounds (1-5) were isolated from the extract of Mundulea sericea leaves. Similar investigation of the roots of this plant afforded an additional three known compounds (6-8). The structures were elucidated using NMR spectroscopic and mass spectrometric analyses. The absolute configuration of 1 was established using ECD spectroscopy. In an antiplasmodial activity assay, compound 1 showed good activity with an IC50 of 2.0 mu M against chloroquine-resistant W2, and 6.6 mu M against the chloroquine-sensitive 3D7 strains of Plasmodium falciparum. Some of the compounds were also tested for antileishmanial activity. Dehydrolupinifolinol (2) and sericetin (5) were active against drug-sensitive Leishmania donovani (MHOM/IN/83/AG83) with IC50 values of 9.0 and 5.0 mu M, respectively. In a cytotoxicity assay, lupinifolin (3) showed significant activity on BEAS-2B (IC50 4.9 mu M) and HePG2 (IC50 10.8 mu M) human cell lines. All the other compounds showed low cytotoxicity (IC50 > 30 mu M) against human lung adenocarcinoma cells (A549), human liver cancer cells (HepG2), lung/bronchus cells (epithelial virus transformed) (BEAS-2B) and immortal human hepatocytes (LO2)},
  language  = {en}
}
@article{BuyinzaDereseNdakalaetal.2021,
  author    = {Buyinza, Daniel and Derese, Solomon and Ndakala, Albert and Heydenreich, Matthias and Yenesew, Abiy and Koch, Andreas and Oriko, Richard},
  title     = {A coumestan and a coumaronochromone from Millettia lasiantha},
  series = {Biochemical systematics and ecology},
  volume    = {97},
  journal   = {Biochemical systematics and ecology},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0305-1978},
  doi       = {10.1016/j.bse.2021.104277},
  pages     = {5},
  year      = {2021},
  abstract  = {The manuscript describes the phytochemical investigation of the roots, leaves and stem bark of Millettia lasiantha resulting in the isolation of twelve compounds including two new isomeric isoflavones lascoumestan and las-coumaronochromone. The structures of the new compounds were determined using different spectroscopic techniques.},
  language  = {en}
}
@article{AtilawHeydenreichNdakalaetal.2014,
  author    = {Atilaw, Yoseph and Heydenreich, Matthias and Ndakala, Albert and Akala, Hoseah M. and Kamau, Edwin and Yenesew, Abiy},
  title     = {3-Oxo-14 alpha, 15 alpha-epoxyschizozygine: A new schizozygane indoline alkaloid from Schizozygia coffaeoides},
  series = {Phytochemistry letters},
  volume    = {10},
  journal   = {Phytochemistry letters},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1874-3900},
  doi       = {10.1016/j.phytol.2014.07.003},
  pages     = {28 -- 31},
  year      = {2014},
  abstract  = {The stem bark extract of Schizozygia coffaeoides (Apocynaceae) showed moderate antiplasmodial activity (IC50 = 8-12 mu g/mL) against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the extract led to the isolation of a new schizozygane indoline alkaloid, named 3-oxo-14 alpha, 15 alpha-epoxyschizozygine. In addition, two dimeric anthraquinones, cassiamin A and cassiamin B, were identified for the first time in the family Apocynaceae. The structures of the isolated compounds were deduced on the basis of spectroscopic evidence. The schizozygane indole alkaloids showed good to moderate antiplasmodial activities (IC50 = 13-52 mu m). (C) 2014 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{AdemMbavengKueteetal.2019,
  author    = {Adem, Fozia A. and Mbaveng, Armelle T. and Kuete, Victor and Heydenreich, Matthias and Ndakala, Albert and Irungu, Beatrice and Yenesew, Abiy and Efferth, Thomas},
  title     = {Cytotoxicity of isoflavones and biflavonoids from Ormocarpum kirkii towards multi-factorial drug resistant cancer},
  series = {Phytomedicine : international journal of phytotherapy and phytopharmacology},
  volume    = {58},
  journal   = {Phytomedicine : international journal of phytotherapy and phytopharmacology},
  publisher = {Elsevier},
  address   = {M{\"u}nchen},
  issn      = {0944-7113},
  doi       = {10.1016/j.phymed.2019.152853},
  pages     = {10},
  year      = {2019},
  abstract  = {Background: While incidences of cancer are continuously increasing, drug resistance of malignant cells is observed towards almost all pharmaceuticals. Several isoflavonoids and flavonoids are known for their cytotoxicity towards various cancer cells. Methods: The cytotoxicity of compounds was determined based on the resazurin reduction assay. Caspases activation was evaluated using the caspase-Glo assay. Flow cytometry was used to analyze the cell cycle (propodium iodide (PI) staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP) (JC-1) and reactive oxygen species (ROS) (H2DCFH-DA). CCRF-CEM leukemia cells were used as model cells for mechanistic studies. Results: Compounds 1, 2 and 4 displayed IC50 values below 20 mu M towards CCRF-CEM and CEM/ADR5000 leukemia cells, and were further tested towards a panel of 7 carcinoma cells. The IC50 values of the compounds against carcinoma cells varied from 16.90 mu M (in resistant U87MG.Delta EGFR glioblastoma cells) to 48.67 mu M (against HepG2 hepatocarcinoma cells) for 1, from 7.85 mu M (in U87MG.Delta EGFR cells) to 14.44 mu M (in resistant MDA-MB231/BCRP breast adenocarcinoma cells) for 2, from 4.96 mu M (towards U87MG.Delta EGFRcells) to 7.76 mu M (against MDA-MB231/BCRP cells) for 4, and from 0.07 mu M (against MDA-MB231 cells) to 2.15 mu M (against HepG2 cells) for doxorubicin. Compounds 2 and 4 induced apoptosis in CCRF-CEM cells mediated by MMP alteration and increased ROS production. Conclusion: The present report indicates that isoflavones and biflavonoids from Ormocarpum kirkii are cytotoxic compounds with the potential of being exploited in cancer chemotherapy. Compounds 2 and 4 deserve further studies to develop new anticancer drugs to fight sensitive and resistant cancer cell lines.},
  language  = {en}
}
@article{AdemKueteMbavengetal.2018,
  author    = {Adem, Fozia A. and Kuete, Victor and Mbaveng, Armelle T. and Heydenreich, Matthias and Ndakala, Albert and Irungu, Beatrice and Efferth, Thomas and Yenesew, Abiy},
  title     = {Cytotoxic benzylbenzofuran derivatives from Dorstenia kameruniana},
  series = {Fitoterapia},
  volume    = {128},
  journal   = {Fitoterapia},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0367-326X},
  doi       = {10.1016/j.fitote.2018.04.019},
  pages     = {26 -- 30},
  year      = {2018},
  abstract  = {Chromatographic separation of the extract of the roots of Dorstenia kameruniana (family Moraceae) led to the isolation of three new benzylbenzofuran derivatives, 2-(p-hydroxybenzyl)benzofuran-6-ol (1), 2-(p-hydroxybenzyl)-7-methoxybenzofuran-6-ol (2) and 2-(p-hydroxy)-3-(3-methylbut-2-en-1-yl)benzyl)benzofuran-6-ol (3) (named dorsmerunin A, B and C, respectively), along with the known furanocoumarin, bergapten (4). The twigs of Dorstenia kameruniana also produced compounds 1-4 as well as the known chalcone licoagrochalcone A (5). The structures were elucidated by NMR spectroscopy and mass spectrometry. The isolated compounds displayed cytotoxicity against the sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 leukemia cells, where compounds 4 and 5 had the highest activities (IC50 values of 7.17 mu M and 5.16 mu M, respectively) against CCRF-CEM leukemia cells. Compound 5 also showed cytotoxicity against 7 sensitive or drug-resistant solid tumor cell lines (breast carcinoma, colon carcinoma, glioblastoma), with IC50 below 50 mu M, whilst 4 showed selective activity.},
  language  = {en}
}
@article{AdemKueteMbavengetal.2019,
  author    = {Adem, Fozia A. and Kuete, Victor and Mbaveng, Armelle T. and Heydenreich, Matthias and Koch, Andreas and Ndakala, Albert and Irungu, Beatrice and Yenesew, Abiy and Efferth, Thomas},
  title     = {Cytotoxic flavonoids from two Lonchocarpus species},
  series = {Natural Product Research},
  volume    = {33},
  journal   = {Natural Product Research},
  number    = {18},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {Abingdon},
  issn      = {1478-6419},
  doi       = {10.1080/14786419.2018.1462179},
  pages     = {2609 -- 2617},
  year      = {2019},
  abstract  = {A new isoflavone, 4′-prenyloxyvigvexin A (1) and a new pterocarpan, (6aR,11aR)-3,8-dimethoxybitucarpin B (2) were isolated from the leaves of Lonchocarpus bussei and the stem bark of Lonchocarpus eriocalyx, respectively. The extract of L. bussei also gave four known isoflavones, maximaisoflavone H, 7,2′-dimethoxy-3′,4′-methylenedioxyisoflavone, 6,7,3′-trimethoxy-4′,5′-methylenedioxyisoflavone, durmillone; a chalcone, 4-hydroxylonchocarpin; a geranylated phenylpropanol, colenemol; and two known pterocarpans, (6aR,11aR)-maackiain and (6aR,11aR)-edunol. (6aR,11aR)-Edunol was also isolated from the stem bark of L. eriocalyx. The structures of the isolated compounds were elucidated by spectroscopy. The cytotoxicity of the compounds was tested by resazurin assay using drug-sensitive and multidrug-resistant cancer cell lines. Significant antiproliferative effects with IC50 values below 10 μM were observed for the isoflavones 6,7,3′-trimethoxy-4′,5′-methylenedioxyisoflavone and durmillone against leukemia CCRF-CEM cells; for the chalcone, 4-hydroxylonchocarpin and durmillone against its resistant counterpart CEM/ADR5000 cells; as well as for durmillone against the resistant breast adenocarcinoma MDA-MB231/BCRP cells and resistant gliobastoma U87MG.ΔEGFR cells.},
  language  = {en}
}
@article{AbdissaInduliAkalaetal.2013,
  author    = {Abdissa, Negera and Induli, Martha and Akala, Hoseah M. and Heydenreich, Matthias and Midiwo, Jacob O. and Ndakala, Albert and Yenesew, Abiy},
  title     = {Knipholone cyclooxanthrone and an anthraquinone dimer with antiplasmodial activities from the roots of Kniphofia foliosa},
  series = {Phytochemistry letters},
  volume    = {6},
  journal   = {Phytochemistry letters},
  number    = {2},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1874-3900},
  doi       = {10.1016/j.phytol.2013.02.005},
  pages     = {241 -- 245},
  year      = {2013},
  abstract  = {A new phenylanthrone, named knipholone cyclooxanthrone and a dimeric anthraquinone, 10-methoxy-10,7'-(chrysophanol anthrone)-chrysophanol were isolated from the roots of Kniphofia foliosa together with the rare naphthalene glycoside, dianellin. The structures were determined by NMR and mass spectroscopic techniques. The compounds showed antiplasmodial activities against the chloroquine-resistant (W2) and chloroquine-sensitive (D6) strains of Plasmodium falciparum with 10-methoxy-10,7'-(chrysophanol anthrone)-chrysophanol being the most active with IC50 values of 1.17 +/- 0.12 and 4.07 +/- 1.54 mu g/ml, respectively.},
  language  = {en}
}
@article{AbdissaHeydenreichMidiwoetal.2014,
  author    = {Abdissa, Negera and Heydenreich, Matthias and Midiwo, Jacob O. and Ndakala, Albert and Majer, Zsuzsanna and Neumann, Beate and Stammler, Hans-Georg and Sewald, Norbert and Yenesew, Abiy},
  title     = {A xanthone and a phenylanthraquinone from the roots of Bulbine frutescens, and the revision of six seco-anthraquinones into xanthones},
  series = {Phytochemistry letters},
  volume    = {9},
  journal   = {Phytochemistry letters},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1874-3900},
  doi       = {10.1016/j.phytol.2014.04.004},
  pages     = {67 -- 73},
  year      = {2014},
  abstract  = {Phytochemical investigation of the dichloromethane/methanol (1:1) extract of the roots of Bulbine frutescens led to the isolation of a new xanthone, 8-hydroxy-6-methylxanthone-1-carboxylic acid (1) and a new phenylanthraquinone, 6',8-O-dimethylknipholone (2) along with six known compounds. The structures were elucidated on the basis of NMR and MS spectral data analyses. The structure of compound 1 was confirmed through X-ray crystallography which was then used as a reference to propose the revision of the structures of six seco-anthraquinones into xanthones. The isolated compounds were evaluated for cytotoxicity against human cervix carcinoma KB-3-1 cells with the phenylanthraquinone knipholone being the most active (IC50 = 0.43 mu M). Two semi-synthetic knipholone derivatives, knipholone Mannich base and knipholone-1,3-oxazine, were prepared and tested for cytotoxic activity; both showed moderate activities (IC50 value of 1.89 and 2.50 mu M, respectively). (C) 2014 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.},
  language  = {en}
}