Study On Anti-diabetic Active Components Of Litsea Glutinosa

Objective:The purpose of this paper is to clarify the composition of chemical components in the root bark extract of Litsea glutinosa,on the basis of the separation of the chemical components of the root barks of Litsea glutinosa.Through the research on anti-diabetic targets of the alkaloids isolated from the root bark extract of Litsea glutinosa,its anti-diabetic active ingredients were defined.The anti-diabetic effect of Litsea glutinosa root bark extracts were studied by evaluating the effects of Litsea glutinosa root bark extracts on the overall appearance,blood glucose,blood lipids,insulin resistance,inflammation and viscera in ob/ob diabetic mice.Methods:1.Using 70% ethanol solution for reflux extraction,the chemical constituents of the Litsea glutinosa root bark were systematically separated by silica gel column chromatography,Sephadex LH-20 and preparative high performance liquid chromatography(HPLC),according to the physicochemical properties of the compounds.Spectroscopic data including nuclear magnetic resonance(NMR),mass spectrometry(MS),and ultraviolet(UV)spectra were used to identify the structures of the isolated compounds.2.Three-dimensional crystal structures of 14 targets were downloaded from the protein PDB structure database and saved in PDB format.The target protein was structurally processed using the Discovery Dock(4.5)software Flexible Docking module,and each compound was individually docked with 14 targets according to default parameters.3.Alkaloid-rich extract of Litsea glutinosa root barks was orally administrated(50,100 and 200 mg/kg)to ob/ob mice for 4 weeks.Parameters of glucose metabolism,hepatotoxicity,hyperlipidemia and inflammation were measured.Results:1.Twenty chemical components were obtained and identified from the bark of Litsea glutinosa,including 12 cosides compounds:(7R,8S)-3,3,5-trimethoxy-4,7-epoxy-8,5-neolignan-4,9,9-triol9-β-D-xylopyranoside(1),(7S,8R)-3,3,5-trimethoxy-4,7-epoxy-8,5-neolignan-4,9,9-triol9-β-D-xylopyranoside(2),(8R,7’R,8’S)-5-methoxyl ariciresinol9-O-β-D-xylopyranoside(3),(8S,7’S,8’R)-5-methoxylariciresinol9-O-β-Dxylopyranoside(4),schizandriside(5),lyonside(6),isolariciresinol-5-methoxy-iso-Larix a-9-O-β-D-xylopyranoside(7),erythro-guaiacylglycerol-β-O-4-dehydrodisinapylether(8),threo-guaiacylglycerol-β-O-4dehydrodisinapyl ether(9),Dihydrobuddlenol(10),Ssioriside(11),dendranthemoside B(12),5 terpenoids:N-trans-feruloyltyramine(13),N-cis-feruloyl tyramine(14),N-trans-sphingoyltyramine(15),Cinnzeylanol(16),epianhydrocinnzeylanol(17);3 alkaloids: boldine(18),laurolitsine(19)and Coclaurine(20).Among them,compounds 2,3 and 4 are new compounds,and compounds 1,5,6,8,9,10,11,12,13,14,15,16,17 and 20 are isolated from the bark of Litse a glutinosa for the first time.2.Through the docking of 14 bases of boldine and laurolitsine,it was found that these two compounds bind well to PTP1 B protein,suggesting that the efficacy of these components may be closely related to the regulation of PTP1 B.3.Alkaloid-rich of L.glutinosa root barks can decreased body and fat weights without reducing average food intake.Alkaloid-rich of L.glutinosa root barks significantly reduced the serum levels of fasting glucose,glycosylated hemoglobin(HbAlc)and glycosylated serum protein(GSP).Alkaloid-rich of L.glutinosa barks increase liver pyruvate kinase,glucokinase activity and hepatic glycogen content.Alkaloid-rich of L.glutinosa root barks increased insulin sensitivity.Alkaloid-rich extract of L.glutinosa barks also alleviated dyslipidemia,ameliorated liver steatosis,increased the activity of serum lipase and alleviated inflammation.Conclusions:1.In this paper,20 compounds were isolated from the root bark of L.glutinosa,including 3 new compounds,and 14 compounds were isolated from the root bark of L.glutinosa for the first time.Enriches the chemical composition of L.glutinosa.2.Using in vitro cell model,computer virtual screening technology,found that alkaloids have hypoglycemic effect.3.Alkaloid-rich from the root bark of L.glutinosa can play an anti diabetic role,which may work by improving insulin sensitivity.