Isolation and identification of the metabolites of 22,25-dideoxyecdysone from cockroach fat body cultures.

Abstract

Hydroxylation and conjugation were the principal pathways of metabolism of 22,25-dideoxyecdysone in cockroach fat body cultures. The major metabolite isolated and identified was the tetrahydroxy steroid 22-deoxyecdysone; other exdysteroids isolated, in order of decreasing quantities, were 22-deoxy-26-hydroxyecdysone, 22,25-dideoxy-26-hydroxyecdysone, and 22-deoxy-20-hydroxyecdysone. Cockroach fat body from late-instar nymphs appears to lack the mechanism for hydroxylating at C-22. Radioanalyses of the material obtained from enzymic hydrolysis of the conjugate fraction showed 65, 15 and 20% of tetraols, pentaols, and unhydrolyzed conjugates respectively, and no 22,25-dideoxyecdysone. An azasteroid and two nonsteroidal amines that effectively inhibit the activity of 22,25-dideoxyecdysone in the cockroach leg regenerate-fat body culture system enhanced the metabolism of 22,25-dideoxyecdysone, decreased the quantity of the pentaol fraction present, and caused an increase or accumulation of the tetraol and conjugate fractions in the fat body culture system.