Study On The Chemical Composition And Antibacterial Activity Of Asterina Pectinifra

The starfish Asterina pectinifra is also called pentagram and sea five star.It belongs to the genus Asteroidea of Eehiondermata.It has Asterinidae and Asterina.Distributed in the northern part of the Pacific Ocean,it is also widely distributed in China's Yellow Sea and Bohai Sea.In recent years,the special chemical composition of sea star has attracted more and more experts and scholars to study it,and steroidal saponins,polyhydroxysteroids,alkaloids,anthraquinones and lipids have been separated from various starfishes in succession.And other biologically active compounds.According to statistics,most of the compounds isolated from starfish have biological activities such as antibacterial,anti-inflammatory,antihypertensive,antiviral,and antitumor.These compounds have become research hotspots at home and abroad due to their novel chemical structure and remarkable biological activity.At the same time,their pharmacological activities also provide new ideas for the medical field.This project took the sea star Asterina pectinifra from the Yellow Sea as the research object,and extracted and separated it.A dry weight of 10 kg of the starfish Asterina pectinifra was extracted by heating and refluxing with 95%ethanol,petroleum ether and n-butanol to obtain 73 g of crude extract of n-butanol layer.The crude extract of the sample was separated and purified by chromatography to prepare monomer Compounds,and the structure identification of monomer compounds using modern spectroscopy technology,and finally the isolated compounds were tested for bacteriostatic activity.In this experiment,thin layer chromatography,silica gel column chromatography,reversed-phase ODS column chromatography,dextran gel column chromatography(Sephadex LH-20),and high performance liquid chromatography(HPLC)were used to extract the crude n-butanol layer from the starfish Asterina pectinifra.The compounds were separated,and the structures of the separated compounds were identified by combining ~1H NMR and ¹³C NMR with modern spectroscopy techniques.A total of 10 compounds were isolated:(22E)-Ergosta-4,6,14,22-tetraen-3-one(1),(22E)-Ergosta-4,6,8,22-tetraen-3-one(2),(22E)-5a,8a-Epidioxyergosta-6,22E-dien-3?-ol(3),ergosterol(4),5?-cholestane-3?,6?,7?,8,15?,16?,26-heptanol(5),3-O-sulfoasterone(6),asterosaponin P₁(7),L-cyclic(val-pro)ine dipeptide(8),L-cyclic(hydroxypro-phenylalanine)dipeptide(9),dibutyl phthalate(10),auriculatum A(11),butyl 1H-imidazole-4-carboxylate(12).Among them,six steroidal compounds(1-6),one steroidal saponin compound(7),two cyclic dipeptide compounds(8?9)and three other compounds(10-12),compounds 1-4 and 12 were isolated from petrel for the first time.The isolated compounds were tested for antibacterial activity by the microdilution method.The strains selected in this experiment were:fungal Candida albicans(CMCC(F)98001)and bacterial Bacillus subtilis(CMCC(B)63501),Staphylococcus aureus(CMCC(B)26003),and Escherichia coli(CMCC(B)44102).Test results show that compounds 7 and 9 are effective against Escherichia coli(CMCC(B)44102)have inhibitory effects.Compound 7 shows a moderate inhibitory activity with a MIC value of 31.3?g/m L,while compound 9 shows a strong inhibitory activity with a MIC value of 7.8?g/m L;Compound 8 showed strong inhibitory activity on the growth of Staphylococcus aureus(CMCC(B)26003),with a MIC value of 15.6?g/m L,and all other tested compounds against these four None of the tested strains had bacteriostatic activity.