Scheme 1.
Astragaloside biosynthetic pathway. AACT, acetoacetyl-coenzyme A (CoA) thiolase; CAS, cycloartenol synthase; FPS, farnesyl diphosphate synthase; HMGR, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase; HMGS, HMG-CoA synthase; IDI, iso-pentenyl diphosphate isomerase; MVD, mevalonate diphosphate decarboxylase; MK, mevalonate kinase; PMK, phosphomevalonate kinase; SE, squalene epoxidase ; SS, squalene synthase; GT, glyosyltransferase; MVA, mevalonic acid; MVP, 5'-phosphomevalonate; MVPP, 5'-diphosphomevalonate; IPP, isopentenyl diphosphate; DMAPP, dimethylallyl diphosphate; FPP, Farnesyl diphosphate.