Catalytic Site Constraints in the P450s Mediating Loganic Acid (7DLH) and Secologanic Acid Synthesis (SLAS) in .

Terpene indole alkaloids (TIAs) are plant-derived natural products synthesized in low levels in medicinal plants such as and . TIA pathways species utilize several CYP72A subfamily members to form loganic acid from 7-deoxyloganic acid (a simple hydroxylation) as well as secologanin and secologanic acid from loganin and loganic acid (a C-C bond scission). Divergences in the specificities of these P450s have allowed secologanic acid synthases (SLASs) to become bifunctional enzymes capable of performing both reactions.