@misc{BringmannMutanyattaComarMaksimenkaetal.2008,
  author    = {Bringmann, Gerhard and Mutanyatta-Comar, Joan and Maksimenka, Katja and Wanjohi, John M. and Heydenreich, Matthias and Brun, Reto and M{\"u}ller, Werner E. G. and Peter, Martin and Midiwo, Jacob O. and Yenesew, Abiy},
  title     = {Joziknipholones A and B : the First Dimeric Phenylanthraquinones, from the Roots of Bulbine frutescens},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-42638},
  year      = {2008},
  abstract  = {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.},
  language  = {en}
}
@misc{NondoMoshiErastoetal.2017,
  author    = {Nondo, Ramadhani Selemani Omari and Moshi, Mainen Julius and Erasto, Paul and Masimba, Pax Jessey and Machumi, Francis and Kidukuli, Abdul Waziri and Heydenreich, Matthias and Zofou, Denis},
  title     = {Anti-plasmodial activity of Norcaesalpin D and extracts of four medicinal plants used traditionally for treatment of malaria},
  series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe},
  number    = {707},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-42832},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-428325},
  pages     = {8},
  year      = {2017},
  abstract  = {Background: Malaria is an old life-threatening parasitic disease that is still affecting many people, mainly children living in sub-Saharan Africa. Availability of effective antimalarial drugs played a significant role in the treatment and control of malaria. However, recent information on the emergence of P. falciparum parasites resistant to one of the artemisinin-based combination therapies suggests the need for discovery of new drug molecules. Therefore, this study aimed to evaluate the antiplasmodial activity of extracts, fractions and isolated compound from medicinal plants traditionally used in the treatment of malaria in Tanzania. Methods: Dry powdered plant materials were extracted by cold macerations using different solvents. Norcaesalpin D was isolated by column chromatography from dichloromethane root extract of Caesalpinia bonducella and its structure was assigned based on the spectral data. Crude extracts, fractions and isolated compound were evaluated for antiplasmodial activity against chloroquine-sensitive P. falciparum (3D7), chloroquine-resistant P. falciparum (Dd2, K1) and artemisinin-resistant P. falciparum (IPC 5202 Battambang, IPC 4912 Mondolkiri) strains using the parasite lactate dehydrogenase assay. Results: The results indicated that extracts of Erythrina schliebenii, Holarrhena pubescens, Dissotis melleri and C. bonducella exhibited antiplasmodial activity against Dd2 parasites. Ethanolic root extract of E. schliebenii had an IC50 of 1.87 mu g/mL while methanolic and ethanolic root extracts of H. pubescens exhibited an IC50 = 2.05 mu g/mL and IC50 = 2.43 mu g/mL, respectively. Fractions from H. pubescens and C. bonducella roots were found to be highly active against K1, Dd2 and artemisinin-resistant parasites. Norcaesalpin D from C. bonducella root extract was active with IC50 of 0.98, 1.85 and 2.13 mu g/mL against 3D7, Dd2 and IPC 4912-Mondolkiri parasites, respectively. Conclusions: Antiplasmodial activity of norcaesalpin D and extracts of E. schliebenii, H. pubescens, D. melleri and C. bonducella reported in this study requires further attention for the discovery of antimalarial lead compounds for future drug development.},
  language  = {en}
}
@misc{PeterMuivaYenesewetal.2009,
  author    = {Peter, Martin G. and Muiva, Lois M. and Yenesew, Abiy and Derese, Solomon and Heydenreich, Matthias and Akala, Hoseah M. and Eyase, Fredrick and Waters, Norman C. and Mutai, Charles and Keriko, Joseph M. and Walsh, Douglas S.},
  title     = {Antiplasmodial β-hydroxydihydrochalcone from seedpods of Tephrosia elata},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-44437},
  year      = {2009},
  abstract  = {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.},
  language  = {en}
}
@misc{PeterYenesewTwinomuhwezietal.2009,
  author    = {Peter, Martin G. and Yenesew, Abiy and Twinomuhwezi, Hannington and Kabaru, Jacques M. and Akala, Hoseah M. and Kiremire, Bernard T. and Heydenreich, Matthias and Eyase, Fredrick and Waters, Norman C. and Walsh, Douglas S.},
  title     = {Antiplasmodial and larvicidal flavonoids from Derris trifoliata},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-44614},
  year      = {2009},
  abstract  = {From the dichloromethane-methanol (1:1) extract of the seed pods of Derris trifoliata, a new flavanone derivative (S)-lupinifolin 4´-methyl ether was isolated. In addition, the known flavonoids lupinifolin and rotenone were identified. The structures were determined on the basis of spectroscopic evidence. Lupinfolin showed moderate in vitro antiplasmodial activity against the D6 (chloroquine-sensitive) and W2 (chloroquineresistant) strains of Plasmodium falciparum. The different parts of this plant showed larvicidal activities against Aedes aegypti and rotenoids were identified as the active principles.},
  language  = {en}
}