Studies on Monoterpene Glucosides and Related Natural Products. XXIII. Biosynthesis of the Secoiridoid Glucosides, Gentiopicroside, Morroniside, Oleuropein, and Jasminin

Abstract

Tracer experiments revealed that (10-³H)-loganin (2) was incorporated into gentiopicroside (3) in Gentiana triflora var. japonica. (7-³H)-2 and (carbo-¹⁴C-methoxy)-secolo-ganin (10) were also found to be incorporated into morroniside (4) in Gentiana thunbergii and Cornus officinalis, respectively. The biosynthetic pathway of oleuropein-type glucosides in Olea europaea and Jasminum primulinum was further examined by employing (10-³H)-7-deoxyloganic acid (1), (10-³H)-loganin (2), (carbo-¹⁴C-methoxy)-secologanin (10), (8-³H)-and (carbo-³H-methoxy)-kingiside (11), together with (8-³H)-and (carbo-¹⁴C-methoxy)-8-epikingiside (18).