Figure 1

Putative saikosaponin biosynthetic pathway in B. chinense. ACAT, acetyl-CoA acetyltransferase; β-AS, β-amyrin synthase; FPS, farnesyl diphosphate synthase; GT, glycosyltransferase; HMGR, HMG-CoA reductase; HMGS, HMG-CoA synthase; IPPI, isopentenyl diphosphate isomerase; MDD, mevalonate diphosphate decarboxylase; MK, mevalonate kinase; P450, cytochrome P450; PMK, phosphomevalonate kinase; SE, squalene epoxidase; SQS, squalene synthase; SS-a, saikosaponin-a; SS-c, saikosaponin-c; SS-d, saikosaponin-d.