Phytochemical investigation of the stem bark of millettia oblata ssp. Teitensis for antiplasmodial andlarvicidal principles
Abstract
The genus Millettia is rich in flavonoids and isoflavonoids. In the search for compounds
with antiplasmodial and larvicidal activities from medicinal plants, the stem barks of
Millettia oblata ssp. teitensis were analysed. The dried and ground stem barks were
extracted with the CH2ClziMeOH (1: 1) by cold percolation for 24 hours at room
temperature. The crude extracts showed significant antiplasmodial activities with ICso
values of 10.0±2.3 and 12.0±1.2 ug/rnl against chloroquine-resistant (W2) and
chloroquine-sensitive (D6) strains of Plasmodium falciparum, respectively.
Chromatographic separation of the extract led to the isolation of eight compounds. These
were identified as durmillone (1), 4' -prenyloxyderrone (2), maximaisoflavone H (3), 8O-methylretusin
(4), maximaisoflavone J (5), maximaisoflavone B (6), tephrosin (7) and
lupeol (8). 4'-Prenyloxyderrone (2) is a novel compound. The remaining compounds are
reported here for the first time from Millettia oblata ssp. teitensis. The identification of
these compounds was based on spectroscopic techniques eH NMR, l3C NMR, HMBC,
HMQC, COSY, DEPT, UV and MS).
The novel compound, 4' -prenyloxyderrone (2) showed antiplasmodial activity with ICso
of 6.0±O.9 and 5.4±1.0 ug/ml against (W2) and (D6), respectively. Durmillone (1)
showed activity against (W2) and (D6) strains of Plasmodium falciparum with ICsovalue
of 9.8±0.1 and 6.0±1.2 ug/ml, respectively. Lupeol (8) showed antiplasmodial activity
with ICso value of 13.9±O.9 ug/ml against (D6). Tephrosin (7) showed antiplasmodial
activity with ICso value of 11.5±O.3 and 12.7±O.9 ug/ml against (W2) and (D6)
respectively. A mixture of Maximaisoflavone J (5) and Maximaisoflavone B (6) showed
activity against (W2) and (D6) strains of Plasmodium falciparum with ICso value of
16.5±3.5 and 4.6±O.5 ug/rnl, respectively.
Citation
Masters of scienceSponsorhip
University of NairobiPublisher
University of Nairobi Chemistry
Subject
Phytochemical investigationstem bark
millettia oblata ssp. Teitensis
antiplasmodial principles
larvicidal principles