Mechanistic Characterization of a Terpene Synthase for a Diterpene Diol from Chitinophaga jiangningensis

A type I terpene synthase from Chitinophaga jiangningensis is described that produces the diterpene diol jiangning-3,15-diol. The cyclization mechanism toward its tricyclic skeleton bearing one additional hydroxyl group as referred to usual type I diterpene synthase products was deeply investigated by isotopic labeling experiments and DFT calculations. The absolute configuration was established by chemical correlation using stereoselectively deuterated substrates.