Study On Extraction And Antibacterial Activity Of Active Components From Chaenomeles Speciosa

Chaenomeles speciosa（Sweet）Nakai is the mature fruit belongs to the family of Rosaceae and Chaenomeles,native to southwest China.Chaenomeles speciosa is acidic and warm,which is a food and medicinal plant.The results of pharmacological research showed that Chaenomeles speciosa has anti-inflammation,anti-microbial,anti-oxidative,immunoregulation,anti-parkinson,liver protection,anti-tumor and other medicinal activities.The current research results shows that the main active ingredient of Chaenomeles speciosa including triterpene compounds,phenol,benzoic acid,flavonoids,saccharide,essential oils and alkaloids.All of these ingredient has been extracted from it and study on the biological activity also has been carried out.Polyphenols and oleanolic acids,which belong to phenols and triterpenoids,have been the focus of research in recent years because of their various medicinal activities and market demands.The polyphenols and triterpenic acid extraction process from Chaenomeles speciosa was optimized by orthogonal design experiment and the anti-bacterial effect of crude extraction against Aeromonas sobria was also stuied.Then,the inhibitory effect of oleanolic acid on Escherichia coli,Bacillus subtilis,Staphylococcus aureus and Aeromonas sobria was determined.On the basis of the results,the inhibition mechanism of oleanolic acid on Aeromonas sobria was studied.The effects of microwave power,microwave time,ethanol concentration and solid-liquid ratio on the extraction of polyphenols were investigated by single factor experiments.On this basis,the optimum technological conditions of microwave-assisted extraction of Chaenomeles speciosa polyphenol were studied by L₉（3⁴）four-factor and three-level orthogonal experimental design.The best extraction conditions were:microwave power700W,microwave time 90s,ethanol concentration 40%,solid-liquid 1:25,the polyphenols content in the process conditions got to 47.27 mg/g.Enzyme-microwave method was used to extract triterpenic acid from Chaenomeles speciosa.According to orthogonal experimental design,the optimum technological conditions for triterpenic acid extraction by enzyme-microwave method were microwave time 5mins,microwave power 500W,ethanol concentration 80%,enzymolysis pH 3,and the final yield was 0.879%.The minmum inhibitory concentration of crude polyphenols and triterpenic acid against Aeromonas sobria was0.3mg/mL and 0.25mg/mL,respectively.The diameter of the inhibit zone（DIZ）formed by 1.2mg/mL polyphenols to Aeromonas sobria was14.095±0.064mm.Meanwhile,the DIZ value by 0.5mg/mL triterpenic acid was9.645±0.1344mm.Bacteriostatic zone experimental results showed that the size of the inhibition zone of 0.5mg/mL OA on E.coli,B.subtilis,S.aureus and A.sobria was11.52±0.1305,9.56±0.058,10.64±0.1024,9.65±0.1343 mm respectively.Moreover,OA had different inhibitory effects on the growth of 4 kinds of bacteria,and also had different influences on the permeability of their cell membrane.OA affected the cell membrane permeability of A.sobria,and the content of macromolecules in the supernatant of the experimental group was significantly higher than that of the control group.Otherwise,OA had no siginificant effect on intracellular soluble protein by analysis of polyacrylamide gel electrophoresis and Gel-pro analyzer software.OA could result in significant shrinkage of cells surface of A.sobria surveyed by scanning electron microscopy.And the higher the OA concentration,the more obvious the cell shrinkageIn summary,both polyphenols and OA have great antibacterial properties,they could affect the permeability of bacterial cell membranes and can be used as the component of clinical antibacterial drugs.The main inbitory effect of OA on A.sobria by inbititing the integrity of the bacterial cell membrane and thereby inhibit the growth and reproduction of the bacteria.