Novel compounds of the formulae ##STR1## wherein R represents lower alkyl or lower alkoxy, A represents --CH.sub.2 --, --CO-- or ##STR2## n represents an integer of 1 to 8, X represents hydrogen or hydroxyl which may be protected and Y represents hydroxyl which may be protected, and their esters show an excellent action on the lysosomal membranes of cells, and exhibit excellent pharmacological activities such as physiologic host defense control activity, especially immuno-potentiating activity.
该式的新化合物为 ##STR1## 其中R代表低碳基或低碳氧基,A代表--CH.sub.2 --,--CO--或##STR2## n代表1到8的整数,X代表氢或羟基,可以被保护,Y代表羟基,也可以被保护。它们的
酯类对细胞的溶酶体膜具有出色的作用,并表现出出色的药理活性,如生理宿主防御控制活性,特别是免疫增强活性。