New mosquito larvicidal tetranortriterpenoids from Turraea wakefieldii and Turraea floribunda.
The crude methanol extracts of the root barks of Turraea wakefieldii and Turraea floribunda were found to show mosquito larvicidal activity against third-instar larvae of Anopheles gambiae sensu stricto. Four new limonoids comprising a vilasininoid 1 and three havanensinoids 2-4 were isolated from the chloroform fractions of the methanol extracts of T. wakefieldii and T. floribunda, respectively. The structures of the compounds were elucidated by NMR spectroscopy. Compounds 1, 2, and 4 had LD50 values of 7.1, 4.0, and 3.6 ppm, respectively, and were more potent than azadirachtin, which had an LD50 value of 57.1 ppm when tested against larvae of A. gambiae.
International Centre of Insect Physiology and Ecology, P.O. Box 30772, Nairobi, Kenya.
Mary W
MW
Ndung'u
Bakari
B
Kaoneka
Ahmed
A
Hassanali
Wilber
W
Lwande
Antony M
AM
Hooper
Francis
F
Tayman
Oliver
O
Zerbe
Baldwyn
B
Torto
D000818:Animals; D000852:Anopheles / Q000254:growth & development; D007306:Insecticides / Q000737:chemistry / Q000302:isolation & purification*; D007814:Larva; D036701:Limonins / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D029582:Meliaceae / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry
D007306:Insecticides; D036701:Limonins; D010936:Plant Extracts