New apocarotenoids and β-carotene cleavage in Blakeslea trispora
作者:Alejandro F. Barrero、M. Mar Herrador、Pilar Arteaga、Jesús Gil、Jose-Antonio González、Eugenio Alcalde、Enrique Cerdá-Olmedo
DOI:10.1039/c1ob05712j
日期:——
Mixed cultures of strains of opposite sex (âmatedâ cultures) of Blakeslea trispora contain trisporic acids and other apocarotenoids, some of which mediate the sexual responses of this fungus and other Mucorales. In mated cultures of the wild-type strains F986 and F921 we identified eleven apocarotenoids: two C18 trisporoids, three C15 compounds with a monocyclofarnesane skeleton, a C13 compound, and five C7 compounds with a 2-methylhexane skeleton. Six of them are new natural products and two others are new for Blakeslea. Their structures were established by NMR and mass spectra and those of the C7 and C13 compounds were confirmed by chemical synthesis. The finding of these compounds and the presence of approximately equimolecular amounts of the C18, C15, and C7 families led to the conclusion that β-carotene is initially split in three fragments by cleavage of its 13,14 and 11â²,12â² double bonds.