抄録
Racemization of isoleucine has been investigated in the three fractions such as free (S1), soluble (S) and insoluble combined (I) ammo acid fractions extracted from the six fossil shells ranging from Holocene to Pliocene. The interconversion of L-isoleucine to D-alloisoleucine increases with the passage of time, giving the different racemization rates in the three fractions, and the degree of racemization in the insoluble combined fraction which indicates the lowest interconversion rate of the three suggests a possible application to absolute age determination and stratigraphic correlation.
