Extraction, purification and some partial characterization of alpha-amylase inhibitors from wheat Iapar 28-Igapó

alpha-Amylase inhibitors from wheat (Triticum aestivum) cultivar Iapar 28-Igapó were extracted with water in a 1:10 (w:v) ratio and precipitated with ammonium sulfate between 20-50% saturation, followed by DEAE and CM-cellulose chromatography. One inhibitor was purified and designated as CMC-IB, and had electrophoretic mobilities of 0.23 and 0.54 in alkaline and acidic conditions, respectively. This inhibitor was 750 times more active on human salivary alpha-amylase (HSSA) than porcine pancreatic o-amylase (PPA). The preincubation time required for maximum complexation with HSA was 20 minutes and optimum pH of inhibition was 7.5. The inhibitor CMC-IB was stable at 0 degrees C and maintained 50% of inhibitory activity against HSA, when incubated at 98 degrees C for one hour.