基于α-葡萄糖苷酶的降糖苦瓜三萜的挖掘

	基于α-葡萄糖苷酶的降糖苦瓜三萜的挖掘; Extraction of the hypoglycemic triterpenes from Momordica charantia based on α-glucosidase
	高亚
导师	邱明华
摘要	Diabetes mellitus is a chronic disease that is caused by the relative or absolute lack of insulin, which is characterized by metabolic disorders and elevated blood sugar. According to statistics, about 463 million adults worldwide suffer from diabetes in 2019, and 4.2 million of them dying from it. Therefore, it is urgent to prevent and treat diabetes. Researches showed that α-glucosidase is a key enzyme in the sugar metabolism pathway, which could hydrolyze starch, glycogen, etc. into monosaccharides and promote their absorption into the blood circulation. Therefore, α-glucosidase inhibitors are a class of effective drugs for treating diabetes. Momordica charantia, a species of genus Momordica, family Cucurbitaceae. It tastes bitter and is a common vegetable, which can also be used as a traditional Chinese medicine to treat diabetes. However, the key ingredient of its hypoglycemic activity is still unclear. In order to fully exploit the medicinal value of M. charantia, it is necessary to excavate the active components of it methodically. In this paper, the chemical constituents of M. charantia were systematically separated by the bioactivity-guided with α-glucosidase inhibitory activity. Firstly, the fresh M. charantia fruits were pre-treated to obtain four extracts with different polarity. After measuring, it was found that the petroleum ether layer extract and ethyl acetate layer extract of M. charantia had a better inhibitory activity. Based on this, 38 cucurbitane-type triterpenoid monoglycosides, including 16 new compounds, were isolated from the active parts of M. charantia. These compounds were identified by 1D, 2D NMR, HRESIMS, UV, and IR spectrum analysis, which novelty are mainly due to the difference of 19-configuration and side chain. Simultaneously, compounds 2, 4, 18, and 28 showed α-glucosidase inhibitory activity with IC50 values of 19.30, 15.28, 13.31 and 17.22 μM, respectively. Moreover, compounds 6, 13, 19, 20, 27, 34, and 37 showed α-glucosidase inhibitory activity with IC50 values 28.40-69.71 μM, while the positive control group ursolic acid given IC50 value of 25.96 μM (the IC50 value of acarbose is 87.65μM). Among them, except for compound 2, all other active compounds have a glucosyl group. Therefore, we speculated that the cucurbitane-type triterpenes with glucosyl groups may have better hypoglycemic activity. Furthermore, compounds 1-38 were screened for the inhibitory activity of dipeptidyl peptidase-4 (DPP-IV), but the results were not satisfactory. In addition, we summarized the hypoglycemic mechanisms of crude extracts and secondary metabolites of M. charantia in the past five years. It provides a reference for further excavating the active components of M. charantia and elucidating its hypoglycemic mechanism.
	2020-05
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/74122
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	高亚. 基于α-葡萄糖苷酶的降糖苦瓜三萜的挖掘, Extraction of the hypoglycemic triterpenes from Momordica charantia based on α-glucosidase[D],2020.

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