EFFECT OF PLATINUM(II) COMPLEXES OF 4-METHOXY-BENZOIC AND 4-CHLOROBENZOIC ACID HYDRAZIDES ON SACCHAROMYCES-CEREVISIAE

This study reports the anti-yeast effect of the 4-methoxybenzoic acid hydrazide (pmbah), 4-chlorobenzoic acid hydrazide (pcbah) and their Pt (II) complexes: cis- [PtL(2)X(2)] and cis[PtL(NH3)Cl-2] where L is eit her pcbah or pmbah and X is Cl, Br or I. MICs of the 4-substituted ana logues (20 000-625 mu M) are much lower than those of the previously r eported benzoic acid hydrazide and 3-methoxybenzoic acid hydrazide. Co mplex formation results in significant increase of potency which may b e due to a change in the mechanism of action, but the MIC (>400-50 mu M) and the IC50(>400-1 mu M) values show that higher activity of the l igands in the free slate does not result in enhanced complex activity. Differences in the potency of iodo-, chloro- and bromo complexes sugg est MIC and IC50 values may be in correlation with the stability of th e complex; rather than with the activity of the free ligands. Osmotica lly unstable mutants were more susceptible to the compounds than their parent strains, but differences among the parent strains were greater .