Sex pheromone biosynthesis from 14C-hexadecanoic acid in the silkworm moth.

[16-14C]Hexadecanoic acid in dimethyl sulfoxide was applied topically to a sex pheromone gland of the silkworm moth, Bombyx mori L. By the combination of normal-phase TLC and reversed-phase TLC or HPLC, bombykol (the sex pheromone of this species, (10E, 12Z)-10, 12-hexadecadien-1-ol) was purified, and its 14C-incorporation was successfully counted without any contamination by other alcohol components in the gland. The highest incorporation ratio (ca. 1.5%) of the 14C-acid into bombykol was observed when a 1-day-old virgin female was treated 4hr after lighting under a 16:8 light-dark cycle, the gland being excised for extraction 1 or 3 hr after the treatment. This reliable incorporation method is suggested to be useful for further investigations of the biosynthetic pathway. The 14C-acid was also incorporated into other components in the pheromone gland, which have been proposed as precursors of bombykol biosynthesis, namely the (10E, 12Z)-10, 12-hexadecadienoic and (Z)-ll-hexadecenoic acid moieties, hexadecan-1-ol, and (Z)-11-hexadecen-l-ol. The total recovery of radioactivity attained ca. 20%, including the unchanged 14C-acid.