ISOLASI DAN IDENTIFIKASI SENYAWA AKTIF LARVASIDA DARI BIJI MIMBA (Azadirachta indika A. Juss) TERHADAP LARVA NYAMUK DEMAM BERDARAH (Aedes aegypti)

Abstract

Isolation and identification of larvicidal active compounds towards Aedes aegypti from Mimba seed have
been conducted. One kilogram dry powder of Mimba seed was extracted with ethanol at room temperature.
Evaporation of ethanol gave 30 g of crude ethanol extract which showed activity against Aedes aegypti (LC50
282.29). This extract was dissolved into methanol-water (7:3) and was then partitioned with n-hexane, chloroform
and ethyl acetate respectively. The three extracts obtained i.e. n-hexane, chloroform and ethyl acetate were showed
their activity against Aedes aegypti in which the-n-hexane extract was the most active with LC50 of 143.97.
Therefore the n-hexane extract was further purified using silica gel column chromatography with chloroform:nhexane
(9:1) as eluent. Three fractions was obtained i.e. F1, F2 and F3 and they were all active against Aedes aegypti
with LC50 78.45, LC50 113.54 and LC50 58.70 respectively. It can be seen that F3 was the most active fractions but
from TLC result, F1 showed the relatively pure compounds since it only gave one spot. Therefore F1 was further
identified using pyhtochemical testing, Uv-Vis, infrared and GC-MS. It was found that the larvicidal active
compounds F1 was belong to carboxylic acids groups,with l max 290.1 having functional groups such as methyl,
methylene and carbonil. Identification using GC-MS indicated that the larvicidal active compounds F1 was assumed
to be a combination of 7 compounds derived from carboxylic acids including hexa-decanoic acid, etil-hexadecanoate,
oleic acid, etyl-oleate ester, octadecanoic acid, etyl-octadecanoate and dioctyl-hexadioate.