Biological activity of precocene analogues onLocusta migratoria

Structure-optimization studies of C-5-C-8-substituted precocene (P) analogues revealed that 1) compounds disubstituted asymmetrically at C-6, C-7 had an anti-allatal effect only if the C-6 side-group was shorter than that at C-7, 2) in the case of C-5, C-7 disubstitution, activity was enhanced by Me at C-5 whereas MeO caused inactivity. Effects of various other substitutions are also discussed.