Functional and Mechanistic Characterization of the 4,5-diepi-Isoishwarane Synthase from the Liverwort Radula lindenbergiana

Chembiochem. 2024 Feb 19:e202400104. doi: 10.1002/cbic.202400104. Online ahead of print.ABSTRACTThe microbial type sesquiterpene synthase RlMTPSL4 from the liverwort Radula lindenbergiana was investigated for its products, showing the formation of several sesquiterpene hydrocarbons. The main product was structurally characterized as the new compound 4,5-diepi-isoishwarane, while the side products included the known hydrocarbons germacrene A, a-selinene, eremophilene and 4,5-diepi-aristolochene. The cyclization mechanism towards 4,5-diepi-isoishwarane catalyzed by RlMTPSL4 was investigated through isotopic labeling experiments, revealing the stereochemical course for the deprotonation step to the neutral intermediate germacrene A, a reprotonation for its further cyclization, and a 1,2-hydride shift along the cascade. The absolute configuration of 4,5-diepi-isoishwarane was determined using a stereoselective deuteration approach, revealing an absolute configuration typically observed for a microbial type sesquiterpene.PMID:38372483 | DOI:10.1002/cbic.202400104

Source: Chembiochem - February 19, 2024 Category: Biochemistry Authors: Houchao Xu Tobias K öllner Feng Chen Jeroen S Dickschat Source Type: research