Earlier studies showed that several common phenolic antioxidants enhanced the inhibitory action of amphotericin B against various species of yeasts. In the present work a search was made for compounds chemically related to the antioxidants which possess similar activity, greater water solubility, and which would present less of a potential toxicological hazard in the evaluation of drug-antioxidant combinations in vivo. A number of compounds showed these characteristics, the most interesting and potentially useful of which were L-dopa (L-β-3,4-dihydroxyphenylalanine) and dopamine (3,4-dihydroxyphenylethylamine). © 1979, by The British Society for Antimicrobial Chemotherapy.