[关键词]
[摘要]
多糖是众多药用植物中重要的质量标志物，在免疫调节、抗肿瘤等方面具有显著的药理作用。多糖是一类结构复杂、种类繁多、组合多样的生物大分子，其生物合成通路主要包括蔗糖转化、尿苷二磷酸葡萄糖（uridine diphosphate，UDP）-葡萄糖至其他NDP单糖的转化、多糖聚合3个部分。在这一合成过程中涉及的关键酶主要包括蔗糖合成酶（sucrose synthase，SUS）、果糖-6磷酸酯在蔗糖磷酸合成酶（sucrose phosphate synthase，SPS）、蔗糖由转化酶（invertase，INV）、己糖激酶（hexokinase，HK）、果糖激酶（fructokinase，FRK）、UDP-葡萄糖脱氢酶（UGDH）、UDP-葡萄糖焦磷酸化酶（UDP-glucose pyrophosphorylase，UGPase）、UDP-鼠李糖合成酶（UDP-rhamnose synthase，RHM）、磷酸甘露糖突变酶（phosphomannose isomerase，PMM）、GDP-甘露糖焦磷酸化酶（GDP-mannose pyrophosphorylase，GMPP）、糖基转移酶（glycosyl transferases，GTs）等。选取以多糖为主要质量标志物的药用植物为探讨对象，对其多糖生物合成通路、关键酶作用机制及单糖组成进行归纳分析，并对研究中存在的问题和可能的解决思路进行了梳理和展望。对明确药用植物质量标志物多糖生物合成通路，了解关键酶作用机制具有一定的参考价值。
[Key word]
[Abstract]
Polysaccharide is a critical quality marker for many medicinal plants, of which plays important roles in regulating immunity and enhancing tumor resistance. Plant polysaccharide is a kind of biological macromolecules composed of a variety of monosaccharides with complex structure. The biosynthesis pathway could be divided into three parts, sucrose conversion, the conversion of other NDP-sugars from UDP-glucose polysaccharides, in which many key enzymes were involved, e.g. sucrose synthase (SUS), sucrose phosphate synthase (SPS), invertase (INV), hexokinase (HK), fructokinase (FRK), UDP-glucose hydrogenase (UGDH), UDP-glucose pyrophosphorylase (UGPase), UDP-glucose rhamnose synthase (RHM), phosphomannose isomerase (PMM), GDP-mannose pyrophosphorylase (GMPP) and glycosyltransferase (GTs). In this paper, medicinal plants with polysaccharide as the quality marker were taken as objects for discussion, the biosynthesis pathway of polysaccharides, monosaccharide composition of polysaccharides and the roles of involved key enzymes were analyzed. Besides, deficiency in current study of polysaccharide and possible solution are sorted out and prospected. The paper has a certain reference value for clarifying the biosynthesis pathway of quality marker polysaccharide in medicinal plants and understanding the roles of key enzymes.
[中图分类号]
R286
[基金项目]
云南省科技厅应用基础计划面上项目（202001AT070109，2019FB122）；云南省教育厅项目（2021Y464）；云南省科技厅重点研发计划（2019IB009）；云南省南药可持续利用重点实验室项目（202005AG070158）
