Discovery Of Alkaloids In Portulaca Oleracea L.that:Promote GLP-1 Secretion And Its In Vivo Drug Analysis

Portulaca oleracea L.has a long history of treating diabetes.Modern clinical and pharmacological studies have shown that the hypoglycemic effect of purslane is similar to that of GLP-1,which promotes insulin secretion and improves insulin resistance.Chemical composition studies showed that purslane mainly contains polysaccharides,polyphenols and alkaloids.The alkaloid crude extract has better hypoglycemic activity than crude extracts of polysaccharides and polyphenols.The significant hypoglycemic activity of the alkaloid component has gradually attracted the attention of scholars at home and abroad.At present,the research on the efficacy of purslane has only stayed in the crude extract,and the monomer research has not been reported.The hypoglycemic positive drug nateglinide releases insulin after acting on the K_ATPchannel on the pancreaticβcell membrane.It has been found that purslane alkaloids have similar structures to nateglinide as phenylalanine compounds.Purslane alkaloids may cause Ca²⁺influx by closing this channel,thereby promoting GLP-1 secretion and reducing blood glucose.Therefore,this project uses a variety of chromatographic methods（macroporous resin,MCI gel,silica gel,gel,ODS,preparation of liquid phase）.Under the guidance of elemental tracking technology based on LC-QTof/MS,alkaloids in purslane extract were guided and deduplicated for separation,and 13 alkaloid monomer compounds wereisolatedfromthem（（S,E）-1-（3-（4-hydroxyphenyl）acryloyl）indoline-2-carboxylic acid、methyl（S,E）-1-（3-（4-hydroxyphenyl）acryloyl）indoline-2-carboxylicacid、（S,E）-1-（3-（4-hydroxy-3-methoxyphenyl）acryloyl）indoline-2-carboxylic acid、methyl（S）-1-（3-（4-hydroxy-3-methoxyphenyl）propanoyl）indoline-2-carboxylate、（S,E）-1-（3-（3-hydroxy-4-methoxyphenyl）acryloyl）indoline-2-carboxylic acid、methyl（S,E）-1-（3-（3-hydroxy-4-methoxyphenyl）acryloyl）indoline-2-carboxylate、（S,E）-1-（3-（3-hydroxy-4-methoxyphenyl）acryloyl）indoline-2-carboxylate、methyl（S）-1-（3-（3,4-dihydroxyphenyl）propanoyl）indoline-2-carboxylate、methyl（S）-1-cinnamoylindoline-2-carboxylate、Oleracein B、Trollisine、N-trans-Feruloyltyramine、N-Caffenoyldopamine）.Using comprehensive analysis of UV,1D-NMR,2D-NMR,ESI-MS,HR-MS,and CD spectra,the structures of these compounds were identified,of which 9 were new purslane alkaloids,and the method of CD experiment was used to determine and calculate the stereo configuration of chiral compounds.Then the spectroscopic laws such as mass spectrometry and nuclear magnetic resonance of purslane alkaloids were summarized.The above work has laid a material foundation forthe study of the mechanism of hypoglycemic activity of purslane.We Used computer simulation technology to simulate the binding of the isolated monomeric alkaloids to SUR1 protein,and used fluorescent probes and flowcytometry to determine the calcium concentration of some monomeric alkaloids in mouse intestinal STC-1 cells.The effects of these monomeric alkaloids on the secretion of GLP-1 by mouse intestinal STC-1 cells were measured using enzyme-linked immunosorbent assay technology,and the mechanism of GLP-1secretion by intestinal cells based on K_ATPchannels was studied at the molecular and cellular levels.Use preparation liquid,the amount of Neo-Oleracein F（methyl（S,E）-1-（3-（3-hydroxy-4-methoxyphenyl）acryloyl）indoline-2-carboxylate）was accumulated,and the use of Immunohistochemistry techniques to study the effects of Purslane alkaloid 6 on the proliferation of pancreatic islet cells and insulin secretion in the pancreas and GLP-1secretion by intestinal cells were measured through animal experiments.This project not only clarifies the basis of the hypoglycemic active substance of Purslane and its mechanism of action,but also provides new ideas for the research of the mechanism of hypoglycemic activity of other traditional.We clarified the mechanism by which alkaloids in purslane may promote GLP-1secretion by acting on ATP-sensitive potassium channels on intestinal L-cell membranes.This study not only clarified the basis of the hypoglycemic active substance of purslane and its mechanism of action,but also provided new ideas for the research of the mechanism of hypoglycemic activity of other traditional Chinese medicine.