of the carbon skeleton in the indole diterpenes, paxilline, and emindole DA was examined. Intact incorporation of multiply (2)H-labeled 3-geranylgeranylindole into two different fungal metabolites proves 3-geranylgeranylindole to be a biosynthetic intermediate. These results give evidence that indole diterpenes are biosynthesized via epoxidation of a common intermediate, and the subsequent cationic
Cephalotene synthase (CsCTS), a new diterpene synthase from Cephalotaxus sinensis responsible for forming the core skeleton of cephalotane-type diterpenoids, was functionally identified. The cyclization cascade was studied in depth through isotopic labeling experiments and DFT calculations. Site-directed mutagenesis guided by molecular docking revealed the critical amino acid residues for the unique
Allylic polyenyl diphosphates such as geranyl and (E,E,E)-geranylgeranyl diphosphates are ubiquitous substrates for monoterpene and diterpene synthases and transferases in isoprenoid biosynthesis. These enzyme substrates were prepared in asymmetrically labeled form by reduction of 1-deuterio aldehyde precursors with (R)- and (S)-Alpine boranes®, conversion into diethyl phosphates, and SN2 displacements