1.14.13.54	testosterone	lactonization of androstenedione	
1.14.13.54	progesterone	strong, competitive inhibitor of lactonization of 17-ketosteroids	
1.14.13.54	pregnenolone	and other C21-20-ketosteroids which are the substrates for oxygenative esterification of the enzyme, strongly inhibit lactonization of androstenedione	
1.14.13.54	Testosterone acetate	lactonization of androstenedione	
1.14.13.54	5-Pregnene-3beta,20alpha-diol	lactonization of androstenedione