TY - JOUR A1 - Akampurira, Denis A1 - Akala, Hoseah M. A1 - Derese, Solomon A1 - Heydenreich, Matthias A1 - Yenesew, Abiy T1 - A new C-C linked benzophenathridine-2-quinoline dimer, and the antiplasmodial activity of alkaloids from Zanthoxylum holstzianum JF - Natural product research N2 - The CH2Cl2/MeOH (1:1) extract of Zanthoxylum holstzianum stem bark showed good antiplasmodial activity (IC50 2.5 +/- 0.3 and 2.6 +/- 0.3 mu g/mL against the W2 and D6 strains of Plasmodium falciparum, respectively). From the extract five benzophenanthridine alkaloids [8-acetonyldihydrochelerythrine (1), nitidine (2), dihydrochelerythine (3), norchelerythrine (5), arnottianamide (8)]; a 2-quinolone alkaloid [N-methylflindersine (4)]; a lignan [4,4 '-dihydroxy-3,3 '-dimethoxylignan-9,9 '-diyl diacetate (7)] and a dimer of a benzophenanthridine and 2-quinoline [holstzianoquinoline (6)] were isolated. The CH2Cl2/MeOH (1:1) extract of the root bark afforded 1, 3-6, 8, chelerythridimerine (9) and 9-demethyloxychelerythrine (10). Holstzianoquinoline (6) is new, and is the second dimer linked by a C-C bond of a benzophenanthridine and a 2-quinoline reported thus far. The compounds were identified based on spectroscopic evidence. Amongst five compounds (1-5) tested against two strains of P. falciparum, nitidine (IC50 0.11 +/- 0.01 mu g/mL against W2 and D6 strains) and norchelerythrine (IC50 value of 0.15 +/- 0.01 mu g/mL against D6 strain) were the most active. KW - Antiplasmodial KW - benzophenanthridine alkaloid KW - holstzianoquinoline; KW - rutaceae KW - Zanthoxylum holstzianum Y1 - 2022 U6 - https://doi.org/10.1080/14786419.2022.2034810 SN - 1478-6419 SN - 1478-6427 VL - 37 IS - 13 SP - 2161 EP - 2171 PB - Taylor & Francis CY - London [u.a.] ER - TY - JOUR A1 - Buyinza, Daniel A1 - Derese, Solomon A1 - Ndakala, Albert A1 - Heydenreich, Matthias A1 - Yenesew, Abiy A1 - Koch, Andreas A1 - Oriko, Richard T1 - A coumestan and a coumaronochromone from Millettia lasiantha JF - Biochemical systematics and ecology N2 - 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. KW - Millettia lasiantha KW - Leguminosae KW - Coumestan KW - Coumaronochromone Y1 - 2021 U6 - https://doi.org/10.1016/j.bse.2021.104277 SN - 0305-1978 SN - 1873-2925 VL - 97 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Chepkirui, Carolyne A1 - Ochieng, Purity J. A1 - Sarkar, Biswajyoti A1 - Hussain, Aabid A1 - Pal, Chiranjib A1 - Yang, Li Jun A1 - Coghi, Paolo A1 - Akala, Hoseah M. A1 - Derese, Solomon A1 - Ndakala, Albert A1 - Heydenreich, Matthias A1 - Wong, Vincent K. W. A1 - Erdelyi, Mate A1 - Yenesew, Abiy T1 - Antiplasmodial and antileishmanial flavonoids from Mundulea sericea JF - Fitoterapia N2 - 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) KW - Mundulea sericea KW - leguminosae KW - flavanonol KW - flavonol KW - antiplasmodial KW - antileishmanial KW - cytotoxicity Y1 - 2020 U6 - https://doi.org/10.1016/j.fitote.2020.104796 SN - 0367-326X SN - 1873-6971 VL - 149 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Atilaw, Yoseph A1 - Duffy, Sandra A1 - Heydenreich, Matthias A1 - Muiva-Mutisya, Lois A1 - Avery, Vicky M. A1 - Erdelyi, Mate A1 - Yenesew, Abiy T1 - Three Chalconoids and a Pterocarpene from the Roots of Tephrosia aequilata JF - Molecules N2 - In our search for new antiplasmodial agents, the CH2Cl2/CH3OH (1:1) extract of the roots of Tephrosia aequilata was investigated, and observed to cause 100% mortality of the chloroquine-sensitive (3D7) strain of Plasmodium falciparum at a 10 mg/mL concentration. From this extract three new chalconoids, E-2,6-dimethoxy-3,4-(2,2-dimethyl)pyranoretrochalcone (1, aequichalcone A), Z-2,6-dimethoxy-3,4-(2,2-dimethyl)pyranoretrochalcone (2, aequichalcone B), 4-ethoxy-3-hydroxypraecansone B (3, aequichalcone C) and a new pterocarpene, 3,4:8,9-dimethylenedioxy-6a,11a-pterocarpene (4), along with seven known compounds were isolated. The purified compounds were characterized by NMR spectroscopic and mass spectrometric analyses. Compound 1 slowly converts into 2 in solution, and thus the latter may have been enriched, or formed, during the extraction and separation process. The isomeric compounds 1 and 2 were both observed in the crude extract. Some of the isolated constituents showed good to moderate antiplasmodial activity against the chloroquine-sensitive (3D7) strain of Plasmodium falciparum. KW - Tephrosia aequilata KW - chalcone KW - retrochalcone KW - aequichalcone A KW - aequichalcone B KW - aequichalcone C KW - pterocarpene KW - antiplasmodial Y1 - 2017 U6 - https://doi.org/10.3390/molecules22020318 SN - 1420-3049 VL - 22 IS - 2 PB - MDPI CY - Basel ER - TY - JOUR A1 - Muthaura, Charles N. A1 - Keriko, Joseph M. A1 - Mutai, Charles A1 - Yenesew, Abiy A1 - Heydenreich, Matthias A1 - Atilaw, Yoseph A1 - Gathirwa, Jeremiah W. A1 - Irungu, Beatrice N. A1 - Derese, Solomon T1 - Antiplasmodial, cytotoxicity and phytochemical constituents of four maytenus species used in traditional medicine in Kenya JF - The natural products journal N2 - Background: In Kenya, several species of the genus Maytenus are used in traditional medicine to treat many diseases including malaria. In this study, phytochemical constituents and extracts of Maytenus undata, M. putterlickioides, M. senegalensis and M. heterophylla were evaluated to determine compound/s responsible for antimalarial activity. Objective: To isolate antiplasmodial compounds from these plant species which could be used as marker compounds in the standardization of their extracts as a phytomedicine for malaria. Methods: Constituents were isolated through activity-guided fractionation of the MeOH/CHCl3 (1:1) extracts and in vitro inhibition of Plasmodium falciparum. Cytotoxicity was evaluated using Vero cells and the compounds were elucidated on the basis of NMR spectroscopy. Results: Fractionation of the extracts resulted in the isolation of ten known compounds. Compound 1 showed promising antiplasmodial activity with IC50, 3.63 and 3.95 ng/ml against chloroquine sensitive (D6) and resistant (W2) P. falciparum, respectively and moderate cytotoxicity (CC50, 37.5 ng/ml) against Vero E6 cells. The other compounds showed weak antiplasmodial (IC50 > 1.93 mu g/ml) and cytotoxic (CC50 > 39.52 mu g/ml) activities against P. falciparum and Vero E6 cells, respectively. Conclusion: (20 alpha)-3-hydroxy-2-oxo-24-nor-friedela-1(10),3,5,7-tetraen-carboxylic acid-(29)-methyl-ester (pristimerin) (1) was the most active marker and lead compound that warrants further investigation as a template for the development of new antimalarial drugs. Pristimerin is reported for the first time in M. putterlickioides. 3-Hydroxyolean-12-en-28-oic acid (oleanolic acid) (5), stigmast-5-en-3-ol (beta-sitosterol) (6), 3-oxo-28-friedelanoic acid (7), olean-12-en-3-ol (beta-amyrin) (8), lup-20(29)-en-3-ol (lupeol) (9) and lup-20(29)-en-3-one (lupenone) (10) are reported for the first time in M. undata. KW - Antimalarial plants KW - antiplasmodial KW - cytotoxicity KW - marker compound KW - Maytenus spp. KW - phytomedicine KW - pristimerin Y1 - 2017 U6 - https://doi.org/10.2174/2210315507666161206144050 SN - 2210-3155 SN - 2210-3163 VL - 7 IS - 2 SP - 144 EP - 152 PB - Bentham Science Publ. CY - Sharjah ER - TY - JOUR A1 - Deyou, Tsegaye A1 - Marco, Makungu A1 - Heydenreich, Matthias A1 - Pan, Fangfang A1 - Gruhonjic, Amra A1 - Fitzpatrick, Paul A. A1 - Koch, Andreas A1 - Derese, Solomon A1 - Pelletier, Jerry A1 - Rissanen, Kari A1 - Yenesew, Abiy A1 - Erdelyi, Mate T1 - Isoflavones and Rotenoids from the Leaves of Millettia oblata ssp teitensis JF - Journal of natural products N2 - A new isoflavone, 8-prenylmilldrone (1), and four new rotenoids, oblarotenoids A-D (2-5), along with nine known compounds (6-14), were isolated from the CH2Cl2/CH3OH (1:1) extract of the leaves of Millettia oblata ssp. teitensis by chromatographic separation. The purified compounds were identified by NMR spectroscopic and mass spectrometric analyses, whereas the absolute configurations of the rotenoids were established on the basis of chiroptical data and in some cases by single-crystal X-ray crystallography. Maximaisoflavone J (11) and oblarotenoid C (4) showed weak activity against the human breast cancer cell line MDA-MB-231 with IC50 values of 33.3 and 93.8 mu M, respectively. Y1 - 2017 U6 - https://doi.org/10.1021/acs.jnatprod.7b00255 SN - 0163-3864 SN - 1520-6025 VL - 80 SP - 2060 EP - 2066 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Muiva-Mutisya, Lois M. A1 - Atilaw, Yoseph A1 - Heydenreich, Matthias A1 - Koch, Andreas A1 - Akala, Hoseah M. A1 - Cheruiyot, Agnes C. A1 - Brown, Matthew L. A1 - Irungu, Beatrice A1 - Okalebo, Faith A. A1 - Derese, Solomon A1 - Mutai, Charles A1 - Yenesew, Abiy T1 - Antiplasmodial prenylated flavanonols from Tephrosia subtriflora JF - Natural Product Research N2 - The CH2Cl2/MeOH (1:1) extract of the aerial parts of Tephrosia subtriflora afforded a new flavanonol, named subtriflavanonol (1), along with the known flavanone spinoflavanone B, and the known flavanonols MS-II (2) and mundulinol. The structures were elucidated by the use of NMR spectroscopy and mass spectrometry. The absolute configuration of the flavanonols was determined based on quantum chemical ECD calculations. In the antiplasmodial assay, compound 2 showed the highest activity against chloroquine-sensitive Plasmodiumfalciparum reference clones (D6 and 3D7), artemisinin-sensitive isolate (F32-TEM) as well as field isolate (KSM 009) with IC50 values 1.4-4.6M without significant cytotoxicity against Vero and HEp2 cell lines (IC50>100M). The new compound (1) showed weak antiplasmodial activity, IC50 12.5-24.2M, but also showed selective anticancer activity against HEp2 cell line (CC50 16.9M). [GRAPHICS] . KW - Tephrosia subtriflora KW - Leguminosae KW - prenylated flavanonol KW - subtriflavanonol KW - antiplasmodial KW - cytotoxicity Y1 - 2018 U6 - https://doi.org/10.1080/14786419.2017.1353510 SN - 1478-6419 SN - 1478-6427 VL - 32 IS - 12 SP - 1407 EP - 1414 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Yaouba, Souaibou A1 - Koch, Andreas A1 - Guantai, Eric M. A1 - Derese, Solomon A1 - Irungu, Beatrice A1 - Heydenreich, Matthias A1 - Yenesew, Abiy T1 - Alkenyl cyclohexanone derivatives from Lannea rivae and Lannea schweinfurthii JF - Phytochemistry letters / Phytochemical Society of Europe N2 - Phytochemical investigation of the CH2Cl2/MeOH (1:1) extract of the roots of Lannea rivae (Chiov) Sacleux (Anacardiaceae) led to the isolation of a new alkenyl cyclohexenone derivative: (4R,6S)-4,6-dihydroxy-6-((Z)-nonadec-14′-en-1-yl)cyclohex-2-en-1-one (1), and a new alkenyl cyclohexanol derivative: (2S*,4R*,5S*)-2,4,5-trihydroxy-2-((Z)-nonadec-14′-en-1-yl)cyclohexanone (2) along with four known compounds, namely epicatechin gallate, taraxerol, taraxerone and β-sitosterol; while the stem bark afforded two known compounds, daucosterol and lupeol. Similar investigation of the roots of Lannea schweinfurthii (Engl.) Engl. led to the isolation of four known compounds: 3-((E)-nonadec-16′-enyl)phenol, 1-((E)-heptadec-14′-enyl)cyclohex-4-ene-1,3-diol, catechin, and 1-((E)-pentadec-12′-enyl)cyclohex-4-ene-1,3-diol. The structures of the isolated compounds were determined by NMR spectroscopy and mass spectrometry. The absolute configuration of compound 1 was established by quantum chemical ECD calculations. In an antibacterial activity assay using the microbroth kinetic method, compound 1 showed moderate activity against Escherichia coli while compound 2 exhibited moderate activity against Staphylococcus aureus. Compound 1 also showed moderate activity against E. coli using the disc diffusion method. The roots extract of L. rivae was notably cytotoxic against both the DU-145 prostate cancer cell line and the Vero mammalian cell line (CC50 = 5.24 and 5.20 μg/mL, respectively). Compound 1 was also strongly cytotoxic against the DU-145 cell line (CC50 = 0.55 μg/mL) but showed no observable cytotoxicity (CC50 > 100 μg/mL) against the Vero cell line. The roots extract of L. rivae and L. schweinfurthii, epicatechin gallate as well as compound 1 exhibited inhibition of carageenan-induced inflammation. KW - Lannea rivae KW - Lannea schweinfurthii KW - Alkenyl cyclohexenone KW - Alkenyl cyclohexanone KW - Anti-inflammatory KW - Cytotoxicity KW - Antimicrobial Y1 - 2017 U6 - https://doi.org/10.1016/j.phytol.2017.12.001 SN - 1874-3900 SN - 1876-7486 VL - 23 SP - 141 EP - 148 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Adem, Fozia A. A1 - Kuete, Victor A1 - Mbaveng, Armelle T. A1 - Heydenreich, Matthias A1 - Ndakala, Albert A1 - Irungu, Beatrice A1 - Efferth, Thomas A1 - Yenesew, Abiy T1 - Cytotoxic benzylbenzofuran derivatives from Dorstenia kameruniana JF - Fitoterapia N2 - 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. KW - Dorstenia kameruniana KW - Moraceae KW - Benzylbenzofuran KW - Furanocoumarin KW - Chalcone KW - Cytotoxicity Y1 - 2018 U6 - https://doi.org/10.1016/j.fitote.2018.04.019 SN - 0367-326X SN - 1873-6971 VL - 128 SP - 26 EP - 30 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Adem, Fozia A. A1 - Mbaveng, Armelle T. A1 - Kuete, Victor A1 - Heydenreich, Matthias A1 - Ndakala, Albert A1 - Irungu, Beatrice A1 - Yenesew, Abiy A1 - Efferth, Thomas T1 - Cytotoxicity of isoflavones and biflavonoids from Ormocarpum kirkii towards multi-factorial drug resistant cancer JF - Phytomedicine : international journal of phytotherapy and phytopharmacology N2 - 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. KW - Apoptosis KW - Cancer KW - Ormocarpum kirkii KW - Isoflavone KW - Biflavonoid KW - Multi-drug resistance Y1 - 2019 U6 - https://doi.org/10.1016/j.phymed.2019.152853 SN - 0944-7113 SN - 1618-095X VL - 58 PB - Elsevier CY - München ER - TY - JOUR A1 - Adem, Fozia A. A1 - Kuete, Victor A1 - Mbaveng, Armelle T. A1 - Heydenreich, Matthias A1 - Koch, Andreas A1 - Ndakala, Albert A1 - Irungu, Beatrice A1 - Yenesew, Abiy A1 - Efferth, Thomas T1 - Cytotoxic flavonoids from two Lonchocarpus species JF - Natural Product Research N2 - 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. KW - Lonchocarpus bussei KW - Lonchocarpus eriocalyx KW - Leguminosae KW - isoflavone KW - pterocarpan KW - cytotoxicity Y1 - 2019 U6 - https://doi.org/10.1080/14786419.2018.1462179 SN - 1478-6419 SN - 1478-6427 VL - 33 IS - 18 SP - 2609 EP - 2617 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Marco, Makungu A1 - Deyou, Tsegaye A1 - Gruhonjic, Amra A1 - Holleran, John A1 - Duffy, Sandra A1 - Heydenreich, Matthias A1 - Firtzpatrick, Paul A. A1 - Landberg, Goran A1 - Koch, Andreas A1 - Derese, Solomon A1 - Pelletier, Jerry A1 - Avery, Vicky M. A1 - Erdelyi, Mate A1 - Yenesew, Abiy T1 - Pterocarpans and isoflavones from the root bark of Millettia micans and of Millettia dura JF - Phytochemistry letters KW - Millettia micans KW - Millettia dura KW - Pterocarpan KW - Isoflavone KW - Cytotoxicity KW - Plasmodium falciparum Y1 - 2017 U6 - https://doi.org/10.1016/j.phytol.2017.07.012 SN - 1874-3900 SN - 1876-7486 VL - 21 SP - 216 EP - 220 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Irungu, Beatrice N. A1 - Adipo, Nicholas A1 - Orwa, Jennifer A. A1 - Kimani, Francis A1 - Heydenreich, Matthias A1 - Midiwo, Jacob O. A1 - Bjoremark, Per Martin A1 - Hakansson, Mikael A1 - Yenesew, Abiy A1 - Erdelyi, Mate T1 - Antiplasmodial and cytotoxic activities of the constituents of Turraea robusta and Turraea nilotica JF - Journal of ethnopharmacology : an interdisciplinary journal devoted to bioscientific research on indigenous drugs N2 - Ethnopharmacological relevance: Turraea robusta and Turraea nilotica are African medicinal plants used for the treatment of a wide variety of diseases, including malaria. The genus Turraea is rich in limonoids and other triterpenoids known to possess various biological activities. Materials and methods: From the stem bark of T. robusta six compounds, and from various parts of T nilotica eleven compounds were isolated by the use of a combination of chromatographic techniques. The structures of the isolated compounds were elucidated using NMR and MS, whilst the relative configuration of one of the isolated compounds, toonapubesin F, was established by X-ray crystallography. The antiplasmodial activities of the crude extracts and the isolated constituents against the D6 and W2 strains of Plasmodium falciparum were determined using the semiautomated micro dilution technique that measures the ability of the extracts to inhibit the incorporation of (G-H-3, where G is guanine) hypoxanthine into the malaria parasite. The cytotoxicity of the crude extracts and their isolated constituents was evaluated against the mammalian cell lines African monkey kidney (vero), mouse breast cancer (4T1) and human larynx carcinoma (HEp2). Results: The extracts showed good to moderate antiplasmodial activities, where the extract of the stem bark of T. robusta was also cytotoxic against the 4T1 and the HEp2 cells (IC50 < 10 mu g/ml). The compounds isolated from these extracts were characterized as limonoids, protolimonoids and phytosterol glucosides. These compounds showed good to moderate activities with the most active one being azadironolide, IC50 2.4 +/- 0.03 mu M and 1.1 +/- 0.01 mu M against the D6 and W2 strains of Plasmodium falciparum, respectively; all other compounds possessed IC50 14.4-40.5 mu M. None of the compounds showed significant cytotoxicity against vero cells, yet four of them were toxic against the 4T1 and HEp2 cancer cell lines with piscidinol A having IC50 8.0 +/- 0.03 and 8.4 +/- 0.01 mu M against the 4T1 and HEp2 cells, respectively. Diacetylation of piscidinol A resulted in reduced cytotoxicity. Conclusion: From the medicinal plants T. robusta and T. nilotica, twelve compounds were isolated and characterized; two of the isolated compounds, namely 11-epi-toonacilin and azadironolide showed good antiplasmodial activity with the highest selectivity indices. (C) 2015 The Authors. Published by Elsevier Ireland Ltd. KW - Turraea robusta KW - Turraea nilotica KW - Antiplasmodial activity KW - Cytotoxicity KW - Limonoid KW - Toonapubesins F KW - Toonacilin KW - Azadironolide Y1 - 2015 U6 - https://doi.org/10.1016/j.jep.2015.08.039 SN - 0378-8741 VL - 174 SP - 419 EP - 425 PB - Elsevier CY - Clare ER - TY - JOUR A1 - Omosa, Leonidah K. A1 - Amugune, Beatrice A1 - Ndunda, Beth A1 - Milugo, Trizah K. A1 - Heydenreich, Matthias A1 - Yenesew, Abiy A1 - Midiwo, Jacob O. T1 - Antimicrobial flavonoids and diterpenoids from Dodonaea angustifolia JF - South African journal of botany : an international interdisciplinary journal for botanical sciences KW - Dodonaea angustifolia KW - Surface exudates KW - Flavone KW - Flavanone KW - Diterpenoid KW - Antimicrobial activities Y1 - 2014 U6 - https://doi.org/10.1016/j.sajb.2013.11.012 SN - 0254-6299 SN - 1727-9321 VL - 91 SP - 58 EP - 62 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Derese, Solomon A1 - Barasa, Leonard A1 - Akala, Hoseah M. A1 - Yusuf, Amir O. A1 - Kamau, Edwin A1 - Heydenreich, Matthias A1 - Yenesew, Abiy T1 - 4 '-Prenyloxyderrone from the stem bark of Millettia oblata ssp teitensis and the antiplasmodial activities of isoflavones from some Millettia species JF - Phytochemistry letters N2 - The CH2Cl2/MeOH (1: 1) extract of the stem bark of Millettia oblata ssp. teitensis showed antiplasmodial activity (IC50 = 10-12 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 isoflavone, 4'-prenyloxyderrone (1), together with known isoflavones (8-O-methylretusin, durmillone, maximaisoflavone B, maximaisoflavone H and maximaisoflavone J), a rotenoid (tephrosin) and a triterpene (lupeol). Similar investigation of Millettia leucantha resulted in the identification of the isoflavones afrormosin and wistin, and the flavone chrysin. The identification of these compounds was based on their spectroscopic data. Five of the isoflavones isolated from these plants as well as 11 previously reported compounds from Millettia dura were tested and showed good to moderate antiplasmodial activities (IC50 = 13-53 mu M), with the new compound, 4'-prenyloxyderrone, being the most active (IC50 = 13-15 mu M). KW - Millettia oblata ssp teitensis KW - Millettia leucantha KW - Millettia dura; Y1 - 2014 U6 - https://doi.org/10.1016/j.phytol.2014.02.001 SN - 1874-3900 SN - 1876-7486 VL - 8 SP - 69 EP - 72 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Abdissa, Negera A1 - Heydenreich, Matthias A1 - Midiwo, Jacob O. A1 - Ndakala, Albert A1 - Majer, Zsuzsanna A1 - Neumann, Beate A1 - Stammler, Hans-Georg A1 - Sewald, Norbert A1 - Yenesew, Abiy T1 - A xanthone and a phenylanthraquinone from the roots of Bulbine frutescens, and the revision of six seco-anthraquinones into xanthones JF - Phytochemistry letters N2 - 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. KW - Bulbine frutescens KW - Xanthone KW - seco-Anthraquinone KW - Phenylanthraquinone KW - Cytotoxicity KW - Structure revision Y1 - 2014 U6 - https://doi.org/10.1016/j.phytol.2014.04.004 SN - 1874-3900 SN - 1876-7486 VL - 9 SP - 67 EP - 73 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Muiva-Mutisya, Lois A1 - Macharia, Bernard A1 - Heydenreich, Matthias A1 - Koch, Andreas A1 - Akala, Hoseah M. A1 - Derese, Solomon A1 - Omosa, Leonidah K. A1 - Yusuf, Amir O. A1 - Kamau, Edwin A1 - Yenesew, Abiy T1 - 6 alpha-Hydroxy-alpha-toxicarol and (+)-tephrodin with antiplasmodial activities from Tephrosia species JF - Phytochemistry letters N2 - The CH2Cl2/MeOH (1: 1) extract of the roots of Tephrosia villosa showed good antiplasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC50 values of 3.1 +/- 0.4 and 1.3 +/- 0.3 mu g/mL, respectively. Chromatographic separation of the extract yielded a new rotenoid, 6 alpha-hydroxy-alpha-toxicarol, along with five known rotenoids, (rotenone, deguelin, sumatrol, 12 alpha-hydroxy-alpha-toxicarol and villosinol). Similar treatment of the extract of the stem of Tephrosia purpurea (IC50 = 4.1 +/- 0.4 and 1.9 +/- 0.2 mu g/mL against D6 and W2 strains of P. falciparum, respectively) yielded a new flavone having a unique substituent at C-7/C-8 [trivial name (+)-tephrodin], along with the known flavonoids tachrosin, obovatin methyl ether and derrone. The relative configuration and the most stable conformation in (+)-tephrodin was determined by NMR and theoretical energy calculations. The rotenoids and flavones tested showed good to moderate antiplasmodial activities (IC50 = 9 +/- 23 mu M). Whereas the cytotoxicity of rotenoids is known, the flavones (+)-tephrodin and tachrosin did not show significant cytotoxicity (IC50 > 100 mu M;) against mammalian African monkey kidney (vero) and human larynx carcinoma (HEp2) cell lines. (C) 2014 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved. KW - Tephrosia villosa KW - Tephrosia purpurea KW - 6 alpha-Hydroxy-alpha-toxicarol KW - (+)-Tephrodin KW - Plasmodium falciparum Y1 - 2014 U6 - https://doi.org/10.1016/j.phytol.2014.09.002 SN - 1874-3900 SN - 1876-7486 VL - 10 SP - 179 EP - 183 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Atilaw, Yoseph A1 - Heydenreich, Matthias A1 - Ndakala, Albert A1 - Akala, Hoseah M. A1 - Kamau, Edwin A1 - Yenesew, Abiy T1 - 3-Oxo-14 alpha, 15 alpha-epoxyschizozygine: A new schizozygane indoline alkaloid from Schizozygia coffaeoides JF - Phytochemistry letters N2 - 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. KW - Schizozygia coffaeoides KW - Schizozygane indoline alkaloid KW - 3-Oxo-14 alpha, 15 alpha-epoxyschizozygine KW - Dimeric anthraquinone KW - Cassiamin A KW - Cassiamin B Y1 - 2014 U6 - https://doi.org/10.1016/j.phytol.2014.07.003 SN - 1874-3900 SN - 1876-7486 VL - 10 SP - 28 EP - 31 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Juma, Wanyama P. A1 - Akala, Hoseah M. A1 - Eyase, Fredrick L. A1 - Muiva, Lois M. A1 - Heydenreich, Matthias A1 - Okalebo, Faith A. A1 - Gitu, Peter M. A1 - Peter, Martin G. A1 - Walsh, Douglas S. A1 - Imbuga, Mabel A1 - Yenesew, Abiy T1 - Terpurinflavone an antiplasmodial flavone from the stem of Tephrosia Purpurea JF - Phytochemistry letters N2 - The stem extract of Tephrosia purpurea showed antiplasmodial activity against the D6 (chloroquine-sensitive) and W2 (chloroquine-resistant) strains of Plasmodium falciparum with IC(50) values of 10.47 +/- 2.22 mu g/ml and 12.06 +/- 2.54 mu g/ml, respectively. A new prenylated flavone, named terpurinflavone, along with the known compounds lanceolatin A, (-)-semiglabrin and lanceolatin B have been isolated from this extract. The new compound, terpurinflavone, showed the highest antiplasmodial activity with IC(50) values of 3.12 +/- 0.28 mu M (D6) and 6.26 +/- 2.66 mu M (W2). The structures were determined on the basis of spectroscopic evidence. KW - Tephrosia purpurea KW - Leguminosae KW - Stem KW - Flavone KW - Terpurinflavone KW - Antiplasmodial Y1 - 2011 U6 - https://doi.org/10.1016/j.phytol.2011.02.010 SN - 1874-3900 VL - 4 IS - 2 SP - 176 EP - 178 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Gumula, Ivan A1 - Heydenreich, Matthias A1 - Derese, Solomon A1 - Ndiege, Isaiah O. A1 - Yenesew, Abiy T1 - Four isoflavanones from the stem bark of Platycelphium voense JF - Phytochemistry letters N2 - From the stem bark of Platycelphium voense (Leguminosae) four new isoflavanones were isolated and characterized as (S)-5,7-dihydroxy-2 ',4 '-dimethoxy-3 '-(3 ''-methylbut-2 ''-enyl)-isoflavanone (trivial name platyisoflavanone A), (+)-5,7,2 '-trihydroxy-4 '-methoxy-3 '-(3 ''-methylbut-2 ''-enyl)-isoflavanone (platyisoflavanone B), 5,7-dihydroxy-4 '-methoxy-2 ''-(2 '''-hydroxyisopropyl)-dihydrofurano-[4 '',5 '':3 ',2 ']-isoflavanone (platyisoflavanone C) and 5,7,2 ',3 ''-tetrahydroxy-2 '',2 ''-dimethyldihydropyrano-[5 '',6 '':3 ',4 ']-isoflavanone (platyisoflavanone D). In addition, the known isoflavanones, sophoraisoflavanone A and glyasperin F; the isoflavone, formononetin; two flavones, kumatakenin and isokaempferide; as well as two triterpenes, betulin and beta-amyrin were identified. The structures were elucidated on the basis of spectroscopic evidence. Platyisoflavanone A showed antibacterial activity against Mycobacterium tuberculosis in the microplate alamar blue assay (MABA) with MIC = 23.7 mu M, but also showed cytotoxicity (IC50 = 21.1 mu M) in the vero cell test. KW - Platycelphium voense KW - Stem bark KW - Leguminosae KW - Isoflavanones KW - Platyisoflavanone KW - Mycobacterium tuberculosis Y1 - 2012 U6 - https://doi.org/10.1016/j.phytol.2011.11.012 SN - 1874-3900 VL - 5 IS - 1 SP - 150 EP - 154 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Machumi, F. A1 - Yenesew, Abiy A1 - Midiwo, J. O. A1 - Heydenreich, Matthias A1 - Kleinpeter, Erich A1 - Khan, S. A1 - Tekwani, B. L. A1 - Walker, L. A. A1 - Muhammad, I T1 - Antiparasitic and anticancer carvotacetone derivatives from Sphaeranthus bullatus T2 - Planta medica : journal of medicinal plant and natural product research Y1 - 2012 SN - 0032-0943 VL - 78 IS - 11 SP - 1201 EP - 1202 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Induli, Martha A1 - Cheloti, Michael A1 - Wasuna, Antonina A1 - Wekesa, Ingrid A1 - Wanjohi, John M. A1 - Byamukama, Robert A1 - Heydenrich, Matthias A1 - Makayoto, Moses A1 - Yenesew, Abiy T1 - Naphthoquinones from the roots of Aloe secundiflora JF - Phytochemistry letters N2 - Two new naphthoquinones, 5-hydroxy-3,6-dimethoxy-2-methylnaphthalene-1,4-dione and 5,8-dihydroxy-3-methoxy-2-methylnaphthalene-1,4-dione, were isolated from the roots of Aloe secundiflora together with the known compounds chrysophanol, helminthosporin, isoxanthorin, ancistroquinone C, aloesaponarins I and II, aloesaponols I and II, laccaic acid D methyl ester and asphodelin. The structures were elucidated based on spectroscopic evidence. This appears to be the first report on the occurrence of naphthoquinones in the genus Aloe. Aloesaponarin I and 5-hydroxy-3,6-dimethoxy-2-methylnaphthalene-1,4-dione showed anti-bacterial activity against Mycobacterium tuberculosis with MIC values of 21-23 mu g/mL in the Microplate Alamar Blue Assay (MABA) and Low Oxygen Recovery Assay (LORA); 5-hydroxy-3,6-dimethoxy-2-methylnaphthalene-1,4-dione also showed cytotoxicity against the Vero cell line (IC50 = 10.2 mu g/mL). KW - Aloe secundiflora KW - Asphodelaceae KW - Roots KW - Naphthoquinone KW - 5-Hydroxy-3,6-dimethoxy-2-methylnaphthalene-1,4-dione 5,8-Dihydroxy-3-methoxy-2-methylnaphthalene-1,4-dione KW - Anthraquinone KW - Aloesaponarin I KW - Mycobacterium tuberculosis Y1 - 2012 U6 - https://doi.org/10.1016/j.phytol.2012.04.014 SN - 1874-3900 VL - 5 IS - 3 SP - 506 EP - 509 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Machumi, Francis A1 - Yenesew, Abiy A1 - Midiwo, Jacob O. A1 - Heydenreich, Matthias A1 - Kleinpeter, Erich A1 - Tekwani, Babu L. A1 - Khan, Shabana I. A1 - Walker, Larry A. A1 - Muhammad, Ilias T1 - Antiparasitic and anticancer carvotacetone derivatives of Sphaeranthus bullatus JF - Natural product communications : an international journal for communications and reviews N2 - The CH2Cl2-MeOH (1:1) extract of the aerial parts of Sphaeranthus bullatus, an annual herb native to tropical East Africa, showed activity against chloroquine sensitive D6 (IC50 9.7 mu g/mL) and chloroquine resistant W2 (IC50 15.0 mu g/mL) strains of Plasmodium falciparum. Seventeen secondary metabolites were isolated from the extract through conventional chromatographic techniques and identified using various spectroscopic methods. The compounds were evaluated for their in vitro antiplasmodial, antileishmanial and anticancer activities revealing activity of four carvotacetone derivatives, namely 3-acetoxy-7-hydroxy-5-tigloyloxycarvotacetone (1) 3,7-dihydroxy-5-tigloyloxycarvotacetone (2), 3-acetoxy-5,7-dihydroxycarvotacetone (3) and 3,5,7-trihydroxycarvotacetone (4); with antiplasmodial IC50 values of 1.40, 0.79, 0.60 and 3.40 mu g/mL, respectively, against chloroquine sensitive D6 strains of P. falciparum; antiplasmodial activity of IC50 2.00, 0.90, 0.68 and 2.80 mu g/mL respectively, against chloroquine resistant W2 strains of P. falciparum, antileishmanial IC50, values of 0.70, 3.00, 0.70 and 17.00 mu g/mL, respectively, against the parasite L. donovanii promastigotes, and anticancer activity against human SK-MEL, KB, BT-549 and SK-OV-3 tumor cells, with IC50 values between <1.1 - 5.3 mu g/mL, for 1-3. In addition, cytotoxic effects of the active compounds were evaluated against monkey kidney fibroblasts (VERO) and pig kidney epithelial cells (LLC-PK11). The structures of carvotacetone derivatives were determined by ID and 2D NMR spectroscopy; the absolute stereochemical configuration of 3-acetoxy-7-hydroxy-5-tigloyloxycarvotacetone (I) was determined as 3R, 4R, 5S by circular dichroism, specific rotation, H-1 NMR and 2D NMR ROESY and NOESY experiments. KW - Sphaeranthus bullatus KW - Asteraceae KW - Antiplasmodial KW - Antileishmanial KW - Anticancer KW - Carvotacetones Y1 - 2012 SN - 1934-578X VL - 7 IS - 9 SP - 1123 EP - 1126 PB - NPC CY - Westerville ER - TY - JOUR A1 - Abdissa, Negera A1 - Induli, Martha A1 - Akala, Hoseah M. A1 - Heydenreich, Matthias A1 - Midiwo, Jacob O. A1 - Ndakala, Albert A1 - Yenesew, Abiy T1 - Knipholone cyclooxanthrone and an anthraquinone dimer with antiplasmodial activities from the roots of Kniphofia foliosa JF - Phytochemistry letters N2 - 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. KW - Kniphofia foliosa KW - Asphodelaceae KW - Roots KW - Anthraquinone KW - Knipholone cyclooxanthrone KW - 10-Methoxy-10,7 '-(chrysophanol anthrone)-chrysophanol KW - Dianellin KW - Malaria Y1 - 2013 U6 - https://doi.org/10.1016/j.phytol.2013.02.005 SN - 1874-3900 VL - 6 IS - 2 SP - 241 EP - 245 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Mutai, Peggoty A1 - Heydenreich, Matthias A1 - Thoithi, Grace A1 - Mugumbate, Grace A1 - Chibale, Kelly A1 - Yenesew, Abiy T1 - 3-Hydroxyisoflavanones from the stem bark of dalbergia melanoxylon - isolation, antimycobacterial evaluation and molecular docking studies JF - Phytochemistry letters N2 - Two new 3-hydroxyisoflavanones, (S)-3,4',5-trihydroxy-2',7-dimethoxy-3'-prenylisoflavanone (trivial name kenusanone F 7-methyl ether) and (S)-3,5-dihydroxy-2',7-dimethoxy-2 '',2 ''-dimethylpyrano[5 '',6 '':3',4']isoflavanone (trivial name sophoronol-7-methyl ether) along with two known compounds (dalbergin and formononetin) were isolated from the stem bark of Dalbergia melanoxylon. The structures were elucidated using spectroscopic techniques. Kenusanone F 7-methyl ether showed activity against Mycobacterium tuberculosis, whereas both of the new compounds were inactive against the malaria parasite Plasmodium falciparum at 10 mu g/ml. Docking studies showed that the new compounds kenusanone F 7-methyl ether and sophoronol-7-methyl ether have high affinity for the M. tuberculosis drug target INHA. KW - Dalbergia melanoxylon KW - 3-Hydroxyisoflavanone KW - Kenusanone F 7-methyl ether KW - Sophoronol-7-methyl ether KW - Mycobacterium tuberculosis KW - Docking Y1 - 2013 U6 - https://doi.org/10.1016/j.phytol.2013.08.018 SN - 1874-3900 SN - 1876-7486 VL - 6 IS - 4 SP - 671 EP - 675 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Andayi, Andrew W. A1 - Yenesew, Abiy A1 - Derese, Solomon A1 - Midiwo, Jacob O. A1 - Gitu, Peter M. A1 - Jondiko, Ogoche J. I. A1 - Akala, Hoseah M. A1 - Liyala, Pamela A1 - Wangui, Julia A1 - Waters, Norman C. A1 - Heydenreich, Matthias A1 - Peter, Martin G. T1 - Antiplasmodial flavonoids from Erythrina sacleuxii N2 - The acetone extracts of the root bark and stem bark of Erythrina sacleuxii showed antiplasmodial activities against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the acetone extract of the root bark afforded a new isoflavone, 7-hydroxy-4 -methoxy-3'- prenylisoflavone (trivial name 5-deoxy-3' - prenylbiochanin A) along with known isoflavonoids as the antiplasmodial principles. Flavonoids and isoflavonoids isolated from the stem bark of E. sucleuxii were also tested and showed antiplasmodial activities. The structures were determined on the basis of spectroscopic evidence Y1 - 2006 UR - http://www.thieme-connect.com/ejournals/toc/plantamedica U6 - https://doi.org/10.1055/s-2005-873200 SN - 0032-0943 ER - TY - JOUR A1 - Yenesew, Abiy A1 - Twinomuhwezi, Hannington A1 - Kiremire, Bernard T. A1 - Mbugua, Martin N. A1 - Gitu, Peter M. A1 - Heydenreich, Matthias A1 - Peter, Martin G. T1 - 8-Methoxyneorautenol and radical scavenging flavonoids from Erythrina abyssinica N2 - A new pterocarpan (named 8-methoxyneorautenol) was isolated from the acetone ext. of the root bark of Erythrina abyssinica. In addn., the known isoflavonoid derivs. eryvarin L, erycristagallin and shinpterocarpin were identified for the first time from the roots of this plant. The structures were detd. on the basis of spectroscopic evidence. The new compd. showed selective antimicrobial activity against Trichophyton mentagrophytes. The acetone ext. of the root bark of E. abyssinica showed radical scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). The pterocarpenes, 3-hydroxy-9-methoxy-10-(3,3-dimethylallyl)pterocarpene and erycristagallin, were the most active constituents of the roots of this plant and showing dose-dependent activities similar to that of the std. quercetin. [on SciFinder (R)] Y1 - 2009 UR - http://www.ajol.info/journal_index.php?jid=120&ab=bcse SN - 1011-3924 ER - TY - JOUR A1 - Bringmann, Gerhard A1 - Mutanyatta-Comar, Joan A1 - Maksimenka, Katja A1 - Wanjohi, John M. A1 - Heydenreich, Matthias A1 - Brun, Reto A1 - Müller, Werner E. G. A1 - Peter, Martin G. A1 - Midiwo, Jacob O. A1 - Yenesew, Abiy T1 - Joziknipholones A and B : the first dimeric phenylanthraquinones, from the roots of Bulbine frutescens N2 - From the roots of the African plant Bulbine frutescens (Asphodelaceae), two unprecedented novel dimeric phenylanthraquinones, named joziknipholones A and B, possessing axial and centrochirality, were isolated, together with six known compounds. Structural elucidation of the new metabolites was achieved by spectroscopic and chiroptical methods, by reductive cleavage of the central bond between the monomeric phenylanthraquinone and -anthrone portions with sodium dithionite, and by quantum chemical CD calculations. Based on the recently revised absolute axial configuration of the parent phenylanthraquinones, knipholone and knipholone anthrone, the new dimers were attributed to possess the P- configuration (i.e., with the acetyl portions below the anthraquinone plane) at both axes in the case of joziknipholone A, whereas in joziknipholone B, the knipholone part was found to be M-configured. Joziknipholones A and B are active against the chloroquine resistant strain K1 of the malaria pathogen, Plasmodium falciparum, and show moderate activity against murine leukemic lymphoma L5178y cells. Y1 - 2008 UR - http://www3.interscience.wiley.com/journal/26293/home?CRETRY=1&SRETRY=0 SN - 0947-6539 ER - TY - JOUR A1 - Yenesew, Abiy A1 - Midiwo, Jacob O. A1 - Heydenreich, Matthias A1 - Peter, Martin G. T1 - Four isoflavanones from stem bark of erythrina sacleuxii Y1 - 1998 ER - TY - JOUR A1 - Yenesew, Abiy A1 - Midiwo, Jacob O. A1 - Meisner, M. A1 - Heydenreich, Matthias A1 - Peter, Martin G. T1 - Two prenylated flavanones from stem bark of erythrina burttii Y1 - 1998 ER - TY - JOUR A1 - Yenesew, Abiy A1 - Midiwo, Jacob O. A1 - Heydenreich, Matthias A1 - Schanzenbach, Dirk A1 - Peter, Martin G. T1 - Two Isoflavanones from the Stem Bark of Erythrina sacleuxii N2 - From the stem bark of Erythrina sacleuxii two new isoflavanones, (R)-5,7-dihydroxy-2',4',5'- trimethoxyisoflavanone (trivial name, (R)-2,3-dihydro-7-demethylrobustigenin) and (R)-5-hydroxy- 2',4',5'-trimethoxy-2'',2''- dimethylpyrano[5'',6'':6,7]isoflavanone (trivial name, (R)-saclenone) were isolated. In addition the known compounds shinpterocarpin, 2,3-dehydrokievitone, abyssinone V, abyssinone V-4'-methyl ether, erythrinasinate and 4'-O-methylsigmoidin B were isolated. The structures were determined on the basis of spectroscopic evidence. Y1 - 2000 ER - TY - JOUR A1 - Yenesew, Abiy A1 - Midiwo, Jacob O. A1 - Guchu, S. M. A1 - Heydenreich, Matthias A1 - Peter, Martin G. T1 - Three iosoflav-3-enes and a 2-arylbenzofuran from the root bark of Erythrina burttii N2 - From the root bark of Erythrina burttii three new isoflav-3-enes, 7,4'-dihydroxy-2'-methoxy-6- (1'',1''-dimethylallyl)isoflav-3-ene (trivial name, burttinol-A), 4'-hydroxy-2'- methoxy-(2'',2''-dimethylpyrano[5'',6'':8,7]isoflav-3-ene (trivial name, burttinol-B), 7,4'-dihydroxy-2'-methoxy-8-(3'',3''-dimethylallyl)isoflav-3-ene (trivial name, burttinol-C), and a new 2-arylbenzofuran, 6,4'-dihydroxy-2'-methoxy-5- (1'',1''-dimethylallyl)-2-arylbenzofuran (trivial name, burttinol-D) were isolated. In addition, the known compounds, abyssinone V-4'-methyl ether, bidwillol A, calopocarpin, erybraedin A, erythrabyssin II, isobavachalcone, phaseollidin and phaseollin were identified. The structures were determined on the basis of spectroscopic evidence. Y1 - 2002 ER - TY - THES A1 - Derese, Solomon A1 - Yenesew, Abiy A1 - Midiwo, Jacob O. A1 - Heydenreich, Matthias A1 - Peter, Martin G. T1 - A new isoflavone from stem bark of Millettia dura Y1 - 2003 SN - 1011-3924 ER - TY - JOUR A1 - Yenesew, Abiy A1 - Irungu, Beatrice A1 - Derese, Solomon A1 - Midiwo, Jacob O. A1 - Heydenreich, Matthias A1 - Peter, Martin G. T1 - Two prenylated flavonoids from the stem bark of Erythrina burttii N2 - From the stem bark of Erythrina burttii, a new isoflavone, 5,2',4'-trihydroxy-7-methoxy-6-(3- methylbut-2-enyl)isoflavone (trivial name, 7-O-methylluteone) and a new flavanone, 5,7-dihydroxy-4'-methoxy- 3'-(3-methylbutadienyl)-5'-(3-methylbut-2-enyl)flavanone (trivial name, burttinonedehydrate) along with three known isoflavonoids (8-prenylluteone, 3-O-methylcalopocarpin and genistein) were isolated. The structures were detd. on the basis of spectroscopic evidence. Y1 - 2003 ER - TY - JOUR A1 - Yenesew, Abiy A1 - Induli, M. A1 - Derese, Solomon A1 - Midiwo, Jacob O. A1 - Heydenreich, Matthias A1 - Peter, Martin G. A1 - Akala, Hoseah M. A1 - Wangui, Julia A1 - Liyala, Pamela A1 - Waters, Norman C. T1 - Anti-plasmodial flavonoids from the stem bark of Erythrina abyssinica N2 - The ethyl acetate extract of the stem bark of Erythrina abyssinica showed anti-plasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC50 values of 7.9 +/- 1.1 and 5.3 +/- 0.7 mug/ml, respectively. From this extract, a new chalcone, 2,3,4,4'-tetrahydroxy-5- prenylchalcone (trivial name 5-prenylbutein) and a new flavanone, 4',7-dihydroxy-3'-methoxy-5'- prenylflavanone (trivial name, 5-deoxyabyssinin II) along with known flavonoids have been isolated as the anti- plasmodial principles. The structures were determined on the basis of spectroscopic evidence. (C) 2004 Elsevier Ltd. All rights reserved Y1 - 2004 SN - 0031-9422 ER - TY - JOUR A1 - Yenesew, Abiy A1 - Mushibe, E. K. A1 - Induli, M. A1 - Derese, Solomon A1 - Midiwo, Jacob O. A1 - Kabaru, Jacques M. A1 - Heydenreich, Matthias A1 - Koch, Andreas A1 - Peter, Martin G. T1 - 7a-O-methyldeguelol, a modified rotenoid with an open ring-C, from the roots of Derris trifoloata N2 - From the acetone extract of the roots of Derris trifoliata an isollavonoid derivative, named 7a-O- methyldeguelol, a modified rotenoid with an open ring-C, representing a new sub-class of isollavonoids (the sub-class is here named as rotenoloid), was isolated and characterised. In addition, the known rotenoids, rotenone, deguelin and alpha-toxicarol, were identified. The structures were determined on the basis of spectroscopic evidence. Rotenone and deguelin were identified as the larvicidal principles of the acetone extract of the roots of Derris trifoliata. (c) 2005 Elsevier Ltd. All rights reserved Y1 - 2005 SN - 0031-9422 ER - TY - JOUR A1 - Yenesew, Abiy A1 - Derese, Solomon A1 - Midiwo, Jacob O. A1 - Bii, Christine C. A1 - Heydenreich, Matthias A1 - Peter, Martin G. T1 - Antimicrobial flavonoids from the stem bark of Erythrina burttii N2 - The chloroform extract of the stem bark of Erythrina burttii showed antifungal and antibacterial activities using the disk diffusion method. Flavonoids were identified as the active principles. Activities were observed against fungi and Gram(+) bacteria, but the Gram(-) bacteria Escherichia coli was resistant. (c) 2005 Elsevier B.V. All rights reserved Y1 - 2005 SN - 0367-326X ER - TY - JOUR A1 - Wanjohi, John M. A1 - Yenesew, Abiy A1 - Midiwo, Jacob O. A1 - Heydenreich, Matthias A1 - Peter, Martin G. A1 - Dreyer, M. A1 - Reichert, M. A1 - Bringmann, Gerhard T1 - Three dimeric anthracene derivatives from the fruits of Bulbine abyssinica N2 - From the fruits of Bulbine abyssinica three new dimeric anthracene derivatives, (P)-8,9,1',8'- tetrahydroxy-3,3'-dimethyl[10,7'-bianthracene]-1,4,9',10'- tetraone (trivial name abyquinone A), (10R)-1,4,8,1',8-pentahydroxy-3,3'-dimethyl-[10,7'-bianthracene]9,9',10' (10H)-trione (trivial name abyquinone B), and (10R)-3,4'-dihydro-1,4,8,3',8',9'-hexahydroxy-3,3'- dimethyl-[10,7'-biant hracene]9,1'(10H,2'H)-dione (trivial name abyquinone Q were isolated. Despite their structural differences, these three compounds are connected to each other by the apparently biomimetic conversion of abyquinone C (a preanthraquinonylanthrone with two stereogenic centers) into B (an anthraquinonylanthrone with one stereogenic center) and finally into A (an axially chiral bianthraquinone) under mild conditions, involving a highly efficient center-to-axis chirality transfer. In addition, the known anthraquinones islandicin and chrysophanol were identified. The structures were determined on the basis of spectroscopical evidences, chemical transformations, and quantum chemical CD calculations. (C) 2005 Elsevier Ltd. All rights reserved Y1 - 2005 SN - 0040-4020 ER - TY - JOUR A1 - Yenesew, Abiy A1 - Kiplagat, John T. A1 - Derese, Solomon A1 - Midiwo, Jacob O. A1 - Kabaru, Jacques M. A1 - Heydenreich, Matthias A1 - Peter, Martin G. T1 - Two unusual rotenoid derivatives, 7a-O-methyl-12a-hydroxydeguelol and spiro-13-homo-13-oxaelliptone, from the seeds of Derris trifoliata N2 - The crude methanol extract of the seeds of Derris trifoliata showed potent and dose dependent larvicidal activity against the 2nd instar larvae of Aedes aegypti. From this extract two unusual rotenoid derivatives, a rotenoloid (named 7a-O-methyl-12a-hydroxydeguelol) and a spirohomooxarotenoid (named spiro-13-homo-13-oxaelliptone), were isolated and characterised. In addition a rare natural chromanone (6,7-dimethoxy-4-chromanone) and the known rotenoids rotenone, tephrosin and dehydrodeguelin were identified. The structures were assigned on the basis of spectroscopic evidence. The larvicidal activity of the crude extract is mainly due to rotenone. (c) 2006 Elsevier Ltd. All rights reserved Y1 - 2006 UR - http://www.sciencedirect.com/science/article/pii/S0031942206000045 U6 - https://doi.org/10.1016/j.phytochem.2006.01.002 ER -