Mosquito larvicidal activity of gluanol acetate, a tetracyclic triterpenes derived from Ficus racemosa Linn

The larvicidal activity of crude hexane, ethyl acetate, petroleum ether, acetone, and methanol extracts of the leaf and bark of Ficus racemosa (Moraceae) was assayed for their toxicity against the early fourth-instar larvae of Culex quinquefasciatus (Diptera: Culicidae). The larval mortality was observed after 24-h exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in bark acetone extract of F. racemosa. In the present study, bioassay-guided fractionation of acetone extract led to the separation and identification of a tetracyclic triterpenes derivative; gluanol acetate was isolated and identified as new mosquito larvicidal compound. Gluanol acetate was quite potent against fourth-instar larvae of Aedes aegypti L. (LC50 14.55 and LC90 64.99 ppm), Anopheles stephensi Liston (LC50 28.50 and LC90 106.50 ppm) and C. quinquefasciatus Say (LC50 41.42 and LC90 192.77 ppm). The structure was elucidated from infrared, ultraviolet, H-1-nuclear magnetic resonance (NMR), C-13-NMR, and mass spectral data. This is the first report on the mosquito larvicidal activity of the reported compound from F. racemosa.