@article{AkampuriraAkalaDereseetal.2023, author = {Akampurira, Denis and Akala, Hoseah M. and Derese, Solomon and Heydenreich, Matthias and Yenesew, Abiy}, title = {A new C-C linked benzophenathridine-2-quinoline dimer, and the antiplasmodial activity of alkaloids from Zanthoxylum holstzianum}, series = {Natural product research}, volume = {37}, journal = {Natural product research}, number = {13}, publisher = {Taylor \& Francis}, address = {London [u.a.]}, issn = {1478-6419}, doi = {10.1080/14786419.2022.2034810}, pages = {2161 -- 2171}, year = {2023}, abstract = {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.}, language = {en} } @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{MuivaMutisyaAtilawHeydenreichetal.2018, author = {Muiva-Mutisya, Lois M. and Atilaw, Yoseph and Heydenreich, Matthias and Koch, Andreas and Akala, Hoseah M. and Cheruiyot, Agnes C. and Brown, Matthew L. and Irungu, Beatrice and Okalebo, Faith A. and Derese, Solomon and Mutai, Charles and Yenesew, Abiy}, title = {Antiplasmodial prenylated flavanonols from Tephrosia subtriflora}, series = {Natural Product Research}, volume = {32}, journal = {Natural Product Research}, number = {12}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {1478-6419}, doi = {10.1080/14786419.2017.1353510}, pages = {1407 -- 1414}, year = {2018}, abstract = {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] .}, language = {en} } @article{DereseBarasaAkalaetal.2014, author = {Derese, Solomon and Barasa, Leonard and Akala, Hoseah M. and Yusuf, Amir O. and Kamau, Edwin and Heydenreich, Matthias and Yenesew, Abiy}, title = {4 '-Prenyloxyderrone from the stem bark of Millettia oblata ssp teitensis and the antiplasmodial activities of isoflavones from some Millettia species}, series = {Phytochemistry letters}, volume = {8}, journal = {Phytochemistry letters}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1874-3900}, doi = {10.1016/j.phytol.2014.02.001}, pages = {69 -- 72}, year = {2014}, abstract = {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).}, language = {en} } @article{MuivaMutisyaMachariaHeydenreichetal.2014, author = {Muiva-Mutisya, Lois and Macharia, Bernard and Heydenreich, Matthias and Koch, Andreas and Akala, Hoseah M. and Derese, Solomon and Omosa, Leonidah K. and Yusuf, Amir O. and Kamau, Edwin and Yenesew, Abiy}, title = {6 alpha-Hydroxy-alpha-toxicarol and (+)-tephrodin with antiplasmodial activities from Tephrosia species}, series = {Phytochemistry letters}, volume = {10}, journal = {Phytochemistry letters}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1874-3900}, doi = {10.1016/j.phytol.2014.09.002}, pages = {179 -- 183}, year = {2014}, abstract = {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.}, 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{JumaAkalaEyaseetal.2011, author = {Juma, Wanyama P. and Akala, Hoseah M. and Eyase, Fredrick L. and Muiva, Lois M. and Heydenreich, Matthias and Okalebo, Faith A. and Gitu, Peter M. and Peter, Martin G. and Walsh, Douglas S. and Imbuga, Mabel and Yenesew, Abiy}, title = {Terpurinflavone an antiplasmodial flavone from the stem of Tephrosia Purpurea}, series = {Phytochemistry letters}, volume = {4}, journal = {Phytochemistry letters}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1874-3900}, doi = {10.1016/j.phytol.2011.02.010}, pages = {176 -- 178}, year = {2011}, abstract = {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.}, language = {en} } @article{KeruboMidiwoDereseetal.2013, author = {Kerubo, Leonidah Omosa and Midiwo, Jacob Ogweno and Derese, Solomon and Langat, Moses K. and Akala, Hoseah M. and Waters, Norman C. and Peter, Martin and Heydenreich, Matthias}, title = {Antiplasmodial activity of compounds from the surface exudates of senecio roseiflorus}, series = {Natural product communications : an international journal for communications and reviews}, volume = {8}, journal = {Natural product communications : an international journal for communications and reviews}, number = {2}, publisher = {NPC}, address = {Westerville}, issn = {1934-578X}, pages = {175 -- 176}, year = {2013}, abstract = {From the surface exudates of Senecio roseiflorus fourteen known methylated flavonoids and one phenol were isolated and characterized. The structures of these compounds were determined on the basis of their spectroscopic analysis. The surface exudate and the flavonoids isolated showed moderate to good antiplasmodial activity with 5,4'-dihydroxy-7-dimethoxyflavanone having the highest activity against chloroquine-sensitive (D6) and resistant (W2) strains of Plasmodium falciparum, with IC50 values of 3.2 +/- 0.8 and 4.4 +/- 0.01 mu g/mL respectively.}, 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{AndayiYenesewDereseetal.2006, author = {Andayi, Andrew W. and Yenesew, Abiy and Derese, Solomon and Midiwo, Jacob O. and Gitu, Peter M. and Jondiko, Ogoche J. I. and Akala, Hoseah M. and Liyala, Pamela and Wangui, Julia and Waters, Norman C. and Heydenreich, Matthias and Peter, Martin G.}, title = {Antiplasmodial flavonoids from Erythrina sacleuxii}, issn = {0032-0943}, doi = {10.1055/s-2005-873200}, year = {2006}, abstract = {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}, language = {en} } @article{YenesewInduliDereseetal.2004, author = {Yenesew, Abiy and Induli, M. and Derese, Solomon and Midiwo, Jacob O. and Heydenreich, Matthias and Peter, Martin G. and Akala, Hoseah M. and Wangui, Julia and Liyala, Pamela and Waters, Norman C.}, title = {Anti-plasmodial flavonoids from the stem bark of Erythrina abyssinica}, issn = {0031-9422}, year = {2004}, abstract = {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}, language = {en} }