An impaired glucose tolerance ameliorative agent containing a peak component of partition chromatography of an gramineous plant seeds alcohol extract. The peak component preferably contains an alkylresorcinol (AR) mixture containing a plurality of alkylresorcinols (ARs). The AR mixture preferably contains (1) an AR of general formula (I) wherein R1 is a C15 saturated or unsaturated alkyl group, (2) an AR of formula (I) wherein R1 is a C17 saturated or unsaturated alkyl group, (3) an AR formula (I) wherein R1 is a C19 saturated or unsaturated alkyl group, (4) an AR of formula (I) wherein R1 is a C21 saturated or unsaturated alkyl group, (5) an AR of formula (I) wherein R1 is a C23 saturated or unsaturated alkyl group , and (6) an AR of formula (I) wherein R1 is a C25 saturated or unsaturated alkyl group.R1 is C15-C25 saturated or unsaturated alkyl. R2 is hydrogen or methyl.
