Malaria is a vector borne disease responsible for high morbidity, mortality and poverty in many tropical and subtropical countries. The disease is transmitted through a bite from an infected female
Anopheles
mosquito, amongst which
Anopheles gambiae s.s
serves as the most prevalent vector. The control of
An. gambiae s.s population can therefore lead to a reduction in malaria spreading. Previous studies have reported the crude extracts of
Kotschya thymodora to be active against the larvae of
An. gambiae s.s and
Culex quinquefasciatus
. In this report the phytochemical study on the crude aqueous ethanolic extract of
K. thymodora leaves led to isolation of vanillic acid (
1) and protocatechuic acid (
2). The structures of these compounds and mosquitoes larvicidal activity against
An. gambiae s.s were established by using spectroscopic techniques and WHO protocol of 1996 respectively. The two phenolic acids exhibited a moderate mosquito larvicidal activity with LC
50 of 77.35 μg/mL (vanillic acid,
1) and 62.4 μg/mL (protocatechuic acid,
2) after 48 hrs exposure time. This is the first report on the isolation of the two phenolic acids from plants belonging to the genus
Kotschya and their larvicidal potential against
An. gambiae s.s.