三七总皂苷(Panax notoginseng saponins,PNS)属于达玛烷型三萜皂苷,是中国传统珍贵药材三七的主要活性成分。三七总皂苷对中枢神经系统、心脑血管系统和免疫系统具有较好的保护作用,并被广泛地用于衰老、肿瘤等疾病的治疗。对三七总皂苷生物合成中的关键酶如法呢基焦磷酸合酶(FPS)、鲨烯合成酶(SS)、鲨烯氧化酶(SE)、达玛烯二醇合成酶(DS)、环阿屯醇合成酶(CAS)、P450单加氧酶(CYP450)和糖基转移酶(GT)等在催化机制、基因克隆、转录水平的表达调控及其表达模式和表达组织和器官的特异性方面的研究进展进行综述,并首次总结了多态性和环境胁迫等在三七皂苷生物合成的基因表达调控中的作用,为应用代谢工程人工合成PNS提供依据。
Panax notoginseng saponins(PNS), which belong to dammarane-type triterpenoid saponins, are the main active components of a precious Chinese materia medica(CMM) named Notoginseng Radix. PNS have better protective effects on the central nervous system, cardiovascular system, and immune system, and have been widely used in the treatment of diseases including fibrosis, aging, and neoplasm. This review summarized the research progress in the key enzymes involved in the biosynthesis of PNS, such as farnesyl pyrophaophate synthase(FPS), squalene synthase(SS), squalene oxidase(SE), dammarenediol-II synthase(DS), cycloartenol synthase(CAS), cytochrome P450 monooxygenases(CYP450), and glycosyltransferase(GT) in terms of catalytic mechanism, gene cloning, and expression regulation on the transcriptional level, as well as the specificity in expression patterns and expression tissues and organs. Meanwhile, the effects of polymorphism and environmental stress on the regulation of gene expression have been first summarized. This review provides a basis for artificial synthesis of PNS using metabolic engineering.