Patent ID: 7037536

Claim:
An α-amylase activity inhibitor obtained from a process which comprises: extracting guava leaves and/or guava fruit with one or more solvents selected from among water and hydrophilic solvents to obtain a resultant extract; subjecting the resultant extract to ultrafiltration, to thereby remove substances having a molecular weight of less than 5,000 to thereby obtain a fraction; applying the fraction to a butyl support hydrophobic chromatography column, and eluting at least one substance with an aqueous solution comprising sodium dihydrogenphosphate (0.02 mol/L) and an aqueous solution comprising sodium phosphate (0.02 mol/L) (flow rate: 1 mL/minute) under a pH gradient between the two solutions; and recovering the said at least one eluted substance, which fraction corresponds to the third single peak of an elution curve obtained when the absorbance of the substance is measured at 260 nm.