We synthetized pyridobenzoxazocynone that differs in the enlarged eigh
t-membered heterocyclic system from the basic structure of pyridobenzo
xazepinones a known class of non-nucleoside HIV-1 reverse transcriptas
e inhibitors. Pyridobenzoxazocynone hydrochloride was found to inhibit
HIV-1 reverse transcriptase activity. At concentration 0.35 mu M the
enzyme activity decreased by 64 +/- 14%. Higher concentrations of pyri
dobenzoxazocynone hydrochloride completely abolished the enzyme activi
ty expressed as radioactivity of acid insoluble products. These result
s suggest that pyridobenzoxazocynones may represent a new class of HIV
-1 reverse transcriptase inhibitors.