Amino acid derivatives

摘要

A novel amino acid derivative represented by the general formula (I) shown below or a salt thereof have now been provided by chemical synthesis, and it has been found that these new compounds stimulate proliferation and physiological activities of the T cells of mammals, have an immunomodulating activity and also have an antitumor activity or a carcinostatic activity. It has also been found that these new compounds have an effect of stimulating the proliferation of hematopoietic stem cells. <IMAGE> (I) wherein y is 0 or 1; R1 represents an unsubstituted C1-C8 alkyl group or others; R2 represents a hydrogen atom, a C1-C5 alkyl group or others; R3 represents a hydrogen atom, a C1-C8 alkyl group or others; R4 represents a hydrogen atom, a C1-C3 alkyl group or others; R5 represents a group -OR42, a group <IMAGE> or others.