PURPOSE: To obtain the subject compound expressed by a specific formula, having immunopotentiating action and thrombocytopenia-recovering action and useful as an immunopotentiator, preventing and treating agent for thrombocytopenia, etc.
CONSTITUTION: A compound of formula I [R1 and R2 are each an acyl; R3, R4, R6 and R7 are each H or an alkyl; R5 is H, an alkyl, (protected) OH, amino or R4 and R5 are combined to form a direct bond; X is carbonyl or sulfonyl; Y is an amino acid sequence which is composed of 1-7 amino acids and may be linked through sulfonic acid amide bond (preferably composed of amino acid which may have 2-5 protecting groups and having an end of acidic amino acid, especially L-glutamic acid)[, e.g. 4-[o-[2,3-bis-(palmitoyloxy)propyl]- Nbenzyloxycarbonyl-L-serylamino]benzoyl-L-glutamic acid di-tert-butylester, etc. Furthermore, this compound is preferably obtained by subjecting, e.g. a compound of formula II to acylation reaction with a compound of the formula R-Z [R is same as R1; X is a halogen].
YUKISHIGE KOUICHI
TANIDA SEIICHI
