Abstract
The extract of fruit coats (RB-b) and its various fractions i.e. EtOAc phase of RB-b, RB-b ‘A’ (Acidic fraction of EtOAc phase), RB-b ‘N’ (Neutral fraction of EtOAc phase), PE ‘S’ (petrol-ether soluble fraction of RB-b ‘N’), PE ‘I’ (petrol-ether insoluble fraction of RB-b ‘N’), ‘ES’ (Ether soluble fraction of PE ’S’) and ‘EI’ [Ether insoluble fraction of PE ‘I’, (Exclusively consisted of azadiradione (pure compound)] of neem (Azadirachta indica A. Juss.) were tested against the 4th -instar larvae of Anopheles stephensi Liston. The results of these were compared with permethrin (25 EC). The LC50 value of the extract and its various fractions was found 290, 165, 142, 43, 159, 154, 106 and 15 ppm, respectively. The fraction ‘ES’ was further subfractionated into 13 VLC-fractions (A-M) and LC50 values of these VLC-fractions were 100(A), 200(B), 150(C), 215(H), 107(I), 136(J), 212(K), 66(L) and 182(M) ppm, while that of permethrin used as standard, it was 0.120 ppm.
