| Marine species rich in natural resources belonging to five kingdom,forty-four phyla such a treasure of resources for marine species of marine natural products.Marine natural products are widely derived from microbes and plankton,bryozoans,seaweed(brown algae,green algae,red algae),sponge,coelenterate,mollusks and echinoderms.This paper focuses on the exploration of natural products in red algae and mollusks.The marine red algal species of the genus Laurencia are consisted of 135 species in the world and over 37 of them distributed in China(family Rhodomalaceae,order Ceramiales,class Rhodophyceae,and phylum Rhodophyta).They mainly distribute among tropical,subtropical,and temperate coasts and deep sea part.The genus Laurencia is rich of secondary metabolites.The secondary metabolites of the genus Laurencia are mainly composed of sesquiterpenes,diterpenes,triterpenes,and C15-acetogenins,most of them have halogen elements.It is reported that some of the secondary metabolites of the genus Laurencia have bio-activities such as anti-microbial,cytotoxic,apastia and anti-worms biological activities.This paper sum up the study of metabolites in the genus Laurencia,conclude and enumerate some compounds with novel structures and biological activities.The Laurencia okamurai sample in this paper was collected from Zhanjiang,Guangdou Province,China.Dried and powdered algal material was extracted with organic solvents.Each extract was isolated and purified upon repeated silica gel and Sephadex LH-20 column chromatography,preparative thin layer chromatography(PTLC)and high performance liquid chromatography(HPLC)to obtian pure compounds.Then their structures were identified on the basis of spectroscopic data analysis including 1H NMR,13 C NMR,EIMS and so on.Two compounds were isolated and identified from the Laurencia okamurai sample collected from Zhanjiang,Guangdou Province,China.Mollusks have huge biodiversity which is divided into eight different classes.Mollusks provide a wealth of resources for humans,such as food,shellfish,dyes and drugs.In many cultures in the world,mollusks have been a source of a medical effect for a long time.Although some mollusks are shelled,most mollusks are essentially soft and parts of the species are exposed to seawater containing bacteria and microbes,making it vulnerable to predators and pathogens.However,mollusks,like all invertebrates,have no acquired immunity.This suggests that mollusks must develop alternative defense strategies to protect themselves from microbial attacks.Under the pressure of natural selection,a series of secondary metabolites with different antibacterial,antifungal,antiparasitic and antiviral properties developed in mollusks.Thus,there is growing interest in the study of the biological activity of mollusks extracts and secondary metabolites.The samples of mollusks were collected from Hokkaido,Aomori,Chiba,Shimane,Hiroshima and Gotou.9 kinds of mollusks were Corbicula japonica,Whelk,Venerupis philippinarum,Meretrix lusoria,Pseudocardium sachalinense,Mizuhopecten yessoensis,Todarodes pacificus,Anadara broughtonii and Megangulus venulosa.In this paper,the metabolites of 9 kinds of mollusks were comparatively analyzed based on LC-MS/MS data.The samples were weighed and cut into small pieces,extracted using Bligh / Dyer method or 70% ethanol method.The crude extracts were concentrated by reduced pressure,freeze dried and weighed and adjusted to a concentration of 10 mg / ml.The sample concentration for LC-MS / MS analysis was adjusted to 0.05 mg / ml.Among all these samples Corbicula japonica and scallop are quite different from the others.For they contain the specific compound which molecular weight is 549.The targeted compounds were isolated and purified by Sephadex LH-20 column chromatography and high performance liquid chromatography(HPLC-RID).Their structures were identified on the basis of spectroscopic data analysis including 1H NMR and LC-MS.The construction of this compound was confirmed to be formic acid plus trisaccharide which is combined by ?-1,4-glycoside.Besides,remarkable differences were detected in contents of Corbicula japonica origin from Aomori and Abashiri.Thus the trisaccharide could be used as chemotaxonomy or traceability.The metabolites of Todarodes pacificus origin from different places are quite the same.However,there are difference among the content of some special compounds such as octopine,242.1750/22.53(molecular weight/retention time)and phenylalanine.The detailed analysis of metabolites of every sample also confirmed that the metabolites analysis method based on LC-MS/MS can seek out the characteristic compounds more rapidly and purposively,which makes it more convenient to analysis the chemical components of samples.At the same time,metabolites analyze and compare the difference of the composition and content of samples from different origin can establish a more accurate and rapid method to identify the origin and quality of the samples. |
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