Chemical Constituents And α-Glucosidase Inhibitory Activities Of Machilus Rufipes

Diabetes Mellitus（DM）is a metabolic disorder characterized by persistent hyperglycemia due to insufficient insulin secretion or impairment of islet function.With the rapid changes of human environment,human behavior and life style,the incidence of obesity and diabetes is increasing.Diabetes is now one of the major threats to human health in the 21st century.Natural products have always been an important source of drug research and development.At present,many clinically common anti-inflammatory,antiviral,anti-tumor and other drugs are derived from natural products.Therefore,it is of great scientific significance and practical value to find safe and effective natural compounds with hypoglycemic activity from natural products.Therefore,in order to find a highly effective hypoglycemic activity derived from natural products,the subject has systematically studied the chemical composition and activity of the plants Machilus rufipes H.W.Li.The plants were extracted with 95%ethanol using the dipping method,and the resulting crude extract was fully suspended in water and extracted fhree times with petroleum ether and ethyl acetate and butyl alcohol,respectively.The obtained ethyl acetate phase and butyl alcohol phase were subjected to various separation methods such as MCI column chromatography,silica gel column chromatography,Sephadex LH-20 gel column chromatography,and reversed-phase semi-preparative HPLC.A total of 42 monomer compounds were separated,including seventeen flavonoid compound（1*、2、3*、4-17）,eleven Phenylpropanoids compound（18-29）,thitteen Lignans compound（29-（18）（19）、35*、36-41）,one Terpenes compounds（42*）.Among them,four compounds were new compounds.They are a new flavanocoumarin 1*,a new phenylpropanolin-epicatechin hybrid 3*,a new aryltetrahydronaphthalene lignin lesonoside 35*,and a new C₁₄sesquiterpenoid 42*,respectively.The planar structure and absolute configuration of the new compound were determined using techniques such as nuclear magnetic resonance spectroscopy（NMR）,high-resolution mass spectrometry（HRMS）,optical measurement combined with CD spectroscopy,and calculated CD spectroscopy.In this paper,theα-glucosidase activity inhibition test was carried out on the compounds isolated from Oleifera rubifolia.The results showed that compounds 2、3*、5-7、12、16 and 35*could inhibit theα-glucosidase activity.Notably,compound6 showed a very strong inhibitory activity(IC₅₀ 4.0±0.2μm),which was more than700 times that of the standard control acarbose.Compounds 7 also exhibited goodα-glucosidase inhibitory activities(IC₅₀ values of 4.1±0.04μm,respectively),so further study on these compounds could lead to the development of naturalα-glucosidase inhibitors.