Isolation And Identification Of Theα-Glucosidase Inhibitor From Macroalgae And Studies Of Inhibition Mechanism

The aim of this research is to find anti-diabetes and anti-HIV substances from macroalgae with cL-glucosidase as target. The large-scale screening of a-glucosidase inhibitor from the organic solvent extracts of algae collected from Qingdao was completed, and then the cx-glucosidase inhibitor SQG was isolated and identified after screening of inhibitor from U/va lacuca L.. A rapid spectrophotometric method for determination of SQG was established, and the content and the change with season of SQG in algae were investigated for the selection of material. The method of large-scale preparation of SQG was established to facilitate the discovery of its inhibition mechanism and preclinical investigation. The inhibition theory of SQG on the a-glucosidase was postulated, and it is helpful for further research on drug. This dissertation consists of six sections, and the contents are as the follows. 1. Screening of c-glucosidase inhibitor from the organic solvent extracts of 20 species of alga was completed, and the result indicated that most of alga contains the inhibitor against i-glucosidase 2. The cL-glucosidase inhibitor SQG was isolated and identified after screening from U/va lctciucct L.. 3 A rapid spectrophotometric method for determination of SQG was established. This method has low limit (0.00442imol). 4.. The content and the change with season of SQG in algae were investigated, and we find U/va /actuca L contained large amount of SQG and the content in this species is relatively stable. 5. A method for large-scale preparation of SQG from U/va /actuca L. was described. 6. The 1C50 of SQG was 201.tM and the result of enzyme kinetics show that SQG is the lion-competition inhibitor, and the inhibition constant Ki is 72.31 iM; The function and structLlre of SQG was investigated and the inhibition mechanism was put forward.