Invertase of the alimentary canal of the kola weevil, Sophrorhinus insperatus Faust

ADEDIRE, C.O. and BALOGUN, R.A.

ABSTRACT: The nature of alpha-glucosidase in the alimentary canal of the kola weevil, Sophrorhinus insperatus Faust has been studied with respect to sucrose. In both larval and adult stages of the weevil. the optimum conditions for invertase activity involve a reaction mixture of pH 6.0 and 1% sucrose at 37°C. Enzymatic activity was consistently higher in the larva than in the adult, indicating that the larva is the more destructive stage of the weevil. Extracts of the nuts of Cola nitida and C. acuminata inhibited invertase activity to varying degrees in vitro, thus suggesting the presence of naturally occurring inhibitors in the two kola varieties. The possible roles of these inhibitors in plant resistance mechanisms are discussed.

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