Control of Japanese encephalitis by active principles, 3-(2-Hydroxyphenoxy)-1, 2-propanediol isolated from n-hexane extract of leaf of Mesua ferrea Linn.

Japanese encephalitis is a vector borne disease and the best procedure for control of this disease is control of vector population. Now a day use of phyto-chemicals more preferred over use of chemical insecticides. Isolation, purification and determination of chemical structures of bioactive compounds were done successfully from n-hexane extract of leaf of M. ferrea. The compounds shows better potentiality to control Cx. vishnui 3rd instars larvae. n-hexane extract of leaf of M. ferrea was prepared by Sohxlet apparatus and further used for bioassay against 3rd instars larvae of Cx. vishnui. n-hexane extract was further fractioned by Thin layer chromatography to isolate bioactive compounds. From different band of TLC, bioactive compounds bearing band was isolated by bioassay test. Structures of active principles were determined by FTIR, gas chromatography, mass spectrometry and with the help of library data list. Cent percent mortality of Cx. vishnui larvae was recorded at 45 ppm concentration of n-hexane extract of M. ferrea after 72 h of exposure. In isolated bioactive compounds 3-(2-Hydroxyphenoxy)-1, 2-propanediol is one of predominant compound, may be responsible for mortality of Cx. vishnui larvae. LC50 value for Cx. vishnui 3rd instars larvae of active compound are 26.76, 25.64 and 20.32 ppm for 24 h, 48 h and 72 h respectively. No mortality were recorded when sub lethal concentration (LC50) of 24 h of bioactive compound applied on non-target organisms i.e. Chironomus circumdatus, Daphnia, Diplonychus etc. The compound i.e. 3-(2-Hydroxyphenoxy)-1, 2-propanediol is predominant compound of active principles and its chemical structure is determine which is major component of n-hexane extract of leaf of M. ferrea. These bioactive principles are safe for other organisms (non-target) those share the same natural habitat. [ABSTRACT FROM AUTHOR]