| Sponges are marine invertebrates,which were proven to a rich source of novel secondary metabolites,including steroids,alkaloids,fatty acids,and other chemical substances.The existence of a large number of diverse chemical structures and biological activity of natural products widely sponge.10%sponges have the cytotoxic activity.In addition,there are many peculiar structures with anti-virus,anti-tumor activities.In recent decades the study,isolated from the sponge ingredients have terpenes,alkaloids,steroids,peptides,and other macrolides.Red algae of the genus Laurencia are rich in novel structure and a significant bioactive secondary metabolites.In previous studies,we found that extracts isolated from Laurencia Okamura,found a series of bromophenols sesquiterpene has significant antibacterial,anti-pathogenic microorganisms and other biological activity.In the process of looking lead compound having biological activity,We study unknown species of sponge in the waters near China ’s Fujian Province Meizhou island chemical composition and biological activity to systematic;To modify Okamura Laurencia algae extract laurinterol’s Structure collected from the Nanji Island,Zhejiang Province,get some goals compounds for activity screening studies.The fresh Sponge material was extracted with acetone,each extract was partitioned between water and ether.The ether fraction was purified by repeated silica gel,Sephadex LH-20 column chromatography and high performance liquid chromatography(HPLC)to yield pure compounds,and their structures were elucidated mainly by NMR,mass,infrared spectroscopic techniques and comparison with those reported data in the liaterature.As results,a total of 22 compounds including 3 steroids,1 sesquiterpene,2 sesterterpenoids,4 alkaloids,7 aliphatic esters,3 phenolic and 2 phthalates were isolated and identified from the South China Sea Sponge.Unknown species of sponge collected from the South China Sea,the isolation of alkaloids1-7,1-8,1-9,1-10 were consistent with those of other species of sponges,this showed up the similarities of chemical composition in marine mollusks.Structurally,these simple alkaloids generally contain halogen atoms,since that fits with their growth of marine organism natural geographical environment.The sesterterpenoids 1-1,1-2 containing furan rings are relatively rare in the sponge.They are highly oxidized compounds,as 1-2 has been formed lactone ring.Meanwhile isolated three phenolic compounds 1-11,1-12,1-13,and it is the first such compound 1-13 from nature products.They may be intermediate products of this spong’s secondary metabolites.And three steroids 1-4,1-5,1-6,there are three hydroxyl groups among 1-5 and 1-6.The dry L.okamurai materials was extracted with ethanol,each extract was partitioned between water and diethyl ether.The diethyl ether fraction was purified by repeated silica gel,sephadex LH-20 column chromatography to yield pure compounds,aurinterol and aplysin are the maximum amount of two monomeric compounds.We got 11 compounds through a series of semi-synthetic transformation acetylation passivation bromide,hydrolysis,oxidation by laurinterol and modified the aplysin’s structure obtained two compounds.This series of compounds 2-3,2-5,2-6 are originally designed for the target product,the remaining compounds are derived by synthetically as design ideas.2-3,2-5,2-13 compounds by X diffraction experiments further confirmed the correctness of their structures.The similarities and minor differences between these compounds will help clarify the structure-activity relationships of the bromine phenolic compounds,and find new lead compounds that possess efficient bioactivities.The configurational isomers of 2-3,2-5 and 2-6 were obtained by Structural modificationm.But they were not fully identified by two-dimensional NOE spectrum、One-dimensional NOE spectra、X diffraction.Their only differences are their 1H-NMR chemical shifts,the optical testing of 2-1 to 2-13.Through the compounds 2-1 to 2-13’s optical testings showed the optical rotations of 2-3,2-5,2-6,2-11 is positive value,while the other compounds were negative value.So we have reason to infer these unidentified configurational isomers which the flips between angular methyl on the right side and trimethylene,more research was needed to confirm the argument.Bioactivity assay including inhibition on PTP1B and protection of damage nerve cell showed that some secondary metabolites from the sponge of south china sea,In the bioscreening experiment,the compounds 1-1、1-2、1-6 and 1-13 showed a strong antibacterial activity and PTP1B inhibition,while antibacterial and inhibitor of PTP1B were tested on the products of Laurinterol’s Structural modification,the strongest inhibition on PTP1B were sesterterpene 1-1 and 1-2.Their IC50 were 1.11μg/mL and 0.92μg/mL respectively with oleanolic acid as positive control.Laurinterol’s were the best activity against Staphylococcus aureus,2-1,2-5 and 2-6 also have better activity,and their IC50 were 10μg/ml、40μg/ml、10μg/ml respectively. |
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