Bioefficacy of ?-amylase inhibitors from the seeds of macrotyloma uniflorum and vigna unguiculata against sitophilus oryzae

Author: 
Laxmi Gupta, Sudhakar Deshpande, Sheeja George3 and Sushma Sabharwal

In the present study the bioefficacy of the α­amylase inhibitor from the seeds of Macrotyloma uniflorum and Vigna unguiculata against Sitophilus oryzae larvae has been studied. M. uniflorum α­amylase inhibitor (MUAI) was purified using ion exchange chromatography on a CMC column while V. unguiculata α­amylase inhibitor (VUAI) was purified on a Poros HS- 50 column. Both amylase inhibitors were tested against the fourth instar larvae for their insecticidal activity at different concentrations. Both MUAI and VUAI inhibited the S. oryzae α­amylase in a non-competitive manner, with a Ki value of 2.2 and 1.17 µM respectively. Significant mortality was observed only at higher concentration of the inhibitors.