QSAR of Some Antifungal Benzoxazoles and Oxazolo(4,5‐b)pyridines against C. albicans

A congeneric set of 2,5‐disubstituted benzoxazole (III) and 2‐substituted oxazolo(4,5‐b)pyridine (IV) derivatives 1–46, previously tested for their antifungal activity against C. albicans, were analyzed by quantitative structure‐activity relationship (QSAR) techniques. The activity contributions for either ring system or substituent effects were determined from the correlation equations, and the predictions of the potent antifungally active derivatives were described by the results obtained from the computer‐assisted stepwise regression procedure. The resulting QSAR revealed that oxazolo(4,5‐b) pyridine ring system was more preferable than benzoxazole and the benzyl group at position 2 was more significant than the corresponding phenyl substituent. Although the para substitution of benzyl or phenyl moiety with electron donating/withdrawing groups was neglectable, the nature of the substituents at the 5th position (R₁) of the fused ring system was important for the potency. Substituting this position with electron withdrawing groups like nitro produces an increase in the antifungal activity.