Derivatives of polyene macrolide antibiotics

Abstract

Derivatives of amphoteric polyene macrolide antibiotics which carry, on the lactone ring, a carboxyl group and an amino sugar characterized by a primary amine group, consist of (a) the methyl, ethyl or propyl ester formed by esterification of the carboxyl group, and (b) salts of such polyene esters constituted as acid addition salts formed with the amine group. The derivatives (a) and (b) have effective antimicrobial activity, e.g. antifungal potency, comparable to the base antibiotics, and the acid salts (b), produced by suitable acids, e.g. hydrochlorides, can be made to have good water solubility which is normally unattainable with the base compounds and is of special advantage in a compound which retains strong activity. Other addition salts are also of value, for example to provide lipid-soluble forms of these antifungal polyenes. Esterification of these chemically sensitive antibiotics is unusually successful using diazomethane, diazoethane or diazopropane with tetrahydrofurane as solvent to produce the ester dissolved therein, avoiding degradation of the base antibiotic or of its potency.

Dependencies are inferred from the claim text.