We investigated the effect of maitake (Grifola frondosa) water extract on inhibiting the conversion of C3H10T1/2B2C1 cells into adipocytes. Maitake water extract was fractionated by molecular sieve. Heat-labile compounds strongly inhibiting adipocyte conversion proved to occur in fractions of molecular weight of more than 10, 000 on the basis of activity measurement of glycerol-3-phosphate dehydrogenase.
