Studies On The Extraction,Purification And Bioactivity Of Glycosaminoglycan From Scallop Skirt

Scallop is a bivalve mollusk,which its shell,meat and nacreous layer have extremely high utilization value.It has been a popular nutritional health product since ancient times.In recent years,along with the large-scale research and development of marine organisms,we have found that its scallop skirt has many biological activities such as reducing blood lipid,expanding blood vessels and inhibiting oxidation.During the production and processing of scallop,most scallop skirts are treated as waste and have not been fully developed and utilized.Therefore,the research and development of glycosaminoglycan in scallop skirt has become the current research focus.In this study,scallop skirt was used as raw materials to study the extraction,separation,purification and biological activity of scallop skirt glycosaminoglycan.The main research results are as follows:The extraction results of glycosaminoglycan from scallop skirt were compared by water bath heating,ultrasound and flash extraction combined with protein enzymolysis.It was found that flash extraction combined with protease enzymolysis had the best extraction effect.Among the four enzymes-papain,trypsin,neutral protease and cellulase,neutral protease had the best enzymolysis effect to the glycosaminoglycan extraction.By using single factor and orthogonal experiment analysis,the suitable enzymatic hydrolysis conditions of flash extraction combined with protease were obtained:enzyme dosage 1.1%,solid-liquid ratio 1:14,enzymolysis temperature 40?,enzymolysis time 3 h.It was determined that trichloroacetic acid is the best protein precipitation method by comparing the sevage method,trifluorotrichloroethane method and trichloroacetic acid method.Glycosaminoglycans with different molecular weights?GAG-30,GAG-50 and GAG-80?were obtained by fraction precipitation with 30%,50%and 80%ethanol,with extraction rates of 2.74%,0.56%and 7.68%,respectively.The crude glycosaminoglycan was further separated and purified by DEAE-52 Cellulose ion exchange chromatography and SephadexG-100 gel column chromatography to obtain refined glycosaminoglycan sugar.The spectrum of gycosaminoglycan showed characteristic group absorption peaks of glycosaminoglycan,especially the peak of pyran-type aminopolysaccharide in the wave range of 950-1250 cm^-1 in the infrared spectrum.In this paper,ACE inhibitory and proline endopeptidase?PEP?activities of glycosaminoglycans GAG-30,GAG-50 and GAG-80 obtained by fractional precipitation of ethanol were studied in vitro test.The results showed that the three glycosaminoglycans had certain activities of ACE inhibition with IC₅₀ values of 0.575,0.438 and 7.072mg/mL,respectively.GAG-30andGAG-50 had stronger inhibitory effect on ACE.The scallop skirt glycosaminoglycan had no inhibitory effect on PEP,which meant that it had no anti-depressant biological activity.The research in this paper might provide some theoretical basis for the development and utilization of active polysaccharides in the skirt of marine shellfish.