Biosynthesis of a C21 steroid conjugate in an insect. The conversion of [14C]cholesterol to 5-[14C]pregnen-3 beta,20 beta-diol glucoside in the tobacco hornworm, Manduca sexta.
Following injection into Manduca sexta (L.) female pupae (day 16), [14C]cholesterol was converted to a C21 steroid conjugate, 5-[14C]pregnen-3 beta,20 beta-diol glucoside. The conjugate was isolated from ovaries and eggs and contained three glucose units at least one of which is attached to C-20. The distribution of the other two glucose units remains to be determined. Other than the dealkylation of C-24 alkane or alkene substituents, side-chain cleavage of sterols is uncommon to insects. Here we report the first definitive proof of the biosynthesis of a C21 steroid conjugate from cholesterol in an insect species. The capability of M. sexta to so readily convert cholesterol to a C21 steroid suggests a physiological role for 5-pregnen-3 beta,20 beta-diol in this species.
D000818:Animals; D002784:Cholesterol / Q000378:metabolism*; D005260:Female; D005960:Glucosides / Q000378:metabolism*; D006027:Glycosides / Q000378:metabolism*; D007915:Lepidoptera; D009682:Magnetic Resonance Spectroscopy; D011283:Pregnenes / Q000378:metabolism*; D011284:Pregnenolone / Q000031:analogs & derivatives / Q000378:metabolism
D005960:Glucosides; D006027:Glycosides; D011283:Pregnenes; D011284:Pregnenolone; C009033:5-pregnene-3,20-diol; D002784:Cholesterol; C047500:5-pregnen-3,20-diol glucoside