Identification of crinosterol from astigamatid mites.

A 24-alkylsterol, crinosterol [(24S)-24-methylcholesta-5,22(E)-dien-3beta-ol] has been isolated from sea-dwelling animals, protists and plants. Here, we identified crinosterol from nine species of mites (Acari). The compound was identified by using (1)H-NMR analysis and GCMS spectral data along with the HPLC retention time by comparing with those of the synthesized compound. As far as we know, this is the first report on the identification of crinosterol from arthropods. Furthermore, after Rhizoglyphus robini were fed on artificial diets with d(3)-methionine, d(2)-crinosterol was detected from the mite's extracts. The incorporation of two deuterium atoms into the sterol indicated that a d(3)-methyl group was introduced into the C24 of the side chain to form crinosterol. Although the details of the biosynthesis of crinosterol remain unknown, the discovery of crinosterol in the mites implies the existence of interesting sterol metabolisms in the animals.