Effect of fatty acids and oils on photodegradation of azadirachtin-A

Azadirachtin-A on exposure to UV-light (254 nm) as a thin film on glass sur face gave a isomerised (Z)-2- methylbut-2-enoate product. Half-life of azad irachtin-A as thin film under UV light was found to be 48 min. Azadirachtin -A was irradiated along with saturated and unsaturated fatty acids, and fat ty oils under ultra-violet light as thin film. Saturated fatty acid increas ed the rate of photodegradation of azadirachtin-A, whereas unsaturated fatt y acids such as oleic, linoleic and elaidic acid reduced the rate of degrad ation. Castor, linseed and olive oil accelerated the rate of degradation, w hereas neem oil showed no or little change in the rate of degradation of az adirachtin-A. None of these fatty acids and fatty oils were effective in co ntroling the rate of degradation of azadirachtin-A under UV-light as thin f ilm.