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 - 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 - GEN A1 - Peter, Martin G. A1 - Muiva, Lois M. A1 - Yenesew, Abiy A1 - Derese, Solomon A1 - Heydenreich, Matthias A1 - Akala, Hoseah M. A1 - Eyase, Fredrick A1 - Waters, Norman C. A1 - Mutai, Charles A1 - Keriko, Joseph M. A1 - Walsh, Douglas S. T1 - Antiplasmodial β-hydroxydihydrochalcone from seedpods of Tephrosia elata N2 - From the seedpods of Tephrosia elata, a new β-hydroxydihydrochalcone named (S)-elatadihydrochalcone was isolated. In addition, the known flavonoids obovatachalcone, obovatin, obovatin methyl ether and deguelin were identified. The structures were determined on the basis of spectroscopic evidence. The crude extract and the flavonoids obtained from the seedpods of this plant showed antiplasmodial activities. The literature NMR data on β-hydroxydihydrochalcones is reviewed and the identity of some of the compounds assigned β-hydroxydihydrochalcone skeleton is questioned. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 118 KW - Tephrosia elata KW - Leguminosae KW - Seedpods KW - (S)-Elatadihydrochalcone KW - β-Hydroxydihydrochalcone Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44437 ER -