金钗石斛copacamphane型倍半萜合成酶的探究与应用

	金钗石斛copacamphane型倍半萜合成酶的探究与应用; Exploration and Application of Copacamphane-type Sesquiterpene Synthase from Dendrobium nobile
	刘立
导师	胡江苗
摘要	Dendrobium nobile Lindl. is a perennial epiphytic herb of Dendrobium, it has been included in the Chinese Pharmacopoeia (2020 edition) as one of the basic source plants for “Shi-Hu”. The accumulation of our research group shows that sesquiterpenes and its alkaloids are abundant in nine species of Dendrobium, such as Dendrobium nobile, Dendrobium findlayanum et al. As the main pharmacodynamic components in D.nobile, it possesses a wide range of pharmacological properties including neuroprotection, immune regulation and hypoglycemic effect. The pharmacopoeia stipulates that the content of dendrobine in D.nobile should not be less than 0.4%. Dendrobine belongs to Picrotoxane-type sesquiterpene, which is a kind of characteristic chemical constituents in D.nobile. Copacamphane-type sesquiterpene also belongs to Picrotoxane-type from the investigation of biogenic pathways. Sesquiterpene synthase is the key enzyme in the biosynthetic pathway of sesquiterpenoids, catalyze the formation of the sesquiterpenoid core skeleton from the straight-chain precursor Farnesyl diphosphate (FPP). In this study, Dendrobium nobile was used as the research material to explore the enzymatic characteristics of sesquiterpene synthase through transcriptome analysis and heterologous expression verification. Based on the transcriptome sequencing, the full-length cDNAs of two sesquiterpene synthases were cloned by reverse transcription polymerase chain reaction (RT-PCR). Furthermore, we constructed the prokaryotic expression vector and recombinant the MVA pathway in Escherichia coli to carry out heterologous expression. The results showed that JC6 had no biocatalytic activity, and JC3 could catalyze the farnesyl diphosphate to generate a single product copaborneol. It belongs to the Copacamphane-type sesquiterpene of D.nobile, the yield in E. coli was 44.25 mg/L. This study further analyzed the molecular regulation mechanism of the synthesis of Copacamphane-type sesquiterpene in D.nobile, laying a foundation for the subsequent regulation of biosynthesis of dendrobine.
	2021-05
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/74550
专题	昆明植物所硕博研究生毕业学位论文
推荐引用方式 GB/T 7714	刘立. 金钗石斛copacamphane型倍半萜合成酶的探究与应用, Exploration and Application of Copacamphane-type Sesquiterpene Synthase from Dendrobium nobile[D],2021.

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