The Study On Utilization Technology Of Anti-hyperdemic Extracts From Ascidians

As people’s living standards rise, hyperlipidemia with high incidence and great harm has increased the demand for anti-hyperdemic drugs or functional foods, among which polyunsaturated fatty acids(PUFAs) is one kind of effective molecules. Asidians are typical marine fouling organisms, which are overproducing and have seriously affected the marine environment. Foreign scholars have made remarkable achievements in the research and development of anticancer drugs from ascidians. Also ascidian is important biological resources rich in PUFAs. Our previous study has showed that some liposoluble extracts of ascidians have certain cholesterol-lowing activity. Therefore, the ascidians may have good potent in anti-hyperdemic products development as new natural drug, or new biological resources for functional food.There have not been many research reports on liposoluble and anti-hyperdemic components of Aplidium constellatum and Styela plicata till now. Most of the previous studies focused on their secondary metabolites with other bioactivities, few were on anti-hyperdemic activity. To develop anti-hyperdemic products as new natural drug or new biological resources for functional food on the basis of our previous study, chemical investigations, including study on the changes of the liposoluble components in these two ascidian materials in different seasons, modification of extraction procedure and quantity analysis of the effective sections, and chemical constituents of these two ascidians, were carried out to provide a material for product development with anti-hyperdemic extracts from ascidians in the future.Two dominant species rich in PUFAs——A. constellatum and S. plicata were selected as research objects. Liposoluble components of ascidians which were collected at different times in the same place or at the same time in different places were extracted by the method of solvent dynamic extraction at low temperature, calculating the extraction yields. Quality standard for raw materials would be established by the extraction yields and explored the seasonal variation of liposoluble components. The results showed that extraction yields of liposoluble component vary with seasons but no significant difference; the extraction yields of Styela plicata collected from different locations at the same time showed an increasing trend from north to south. By combination comparison of the extraction yields and natural biomass for sample collection, the suitable collection time is summer and early autumn for A. constellatum, and summer for S. plicata.In this study, orthogonal experimental design was used to optimize the extraction process of ester-soluble components from these two ascidians. Extraction yields and concentrations of carotenoids were chosen as evaluating indicators to assess pros and cons of the process. The result showed that two indicators—the extraction yields and concentrations of carotenoids prompted that A3B3C1 was optimal process condition, namely the ratio of solid to liquid 1:1.5(W/V), the extraction time 8 min, the ratio of solvent(n-butyl alcohol/acetic ether) 1:2(V/V). Validation experiment showed that this condition was the optimal combination of extraction of liposoluble active ingredients from A. constellatum and S. plicata.Quality standard indicators of phospholipid content, EPA+DHA content were developed by analyzing the quality of liposoluble components with methods of gas chromatography(GC) and high performance liquid chromatography(HPLC) methods. In these extracts of both ascidians, relatively higher contents of phospholipid were found at 21.9-51.6%, while quite low contents of EPA+DHA were found only at 1.0-5.7% by HPLC, and the latter was far lower than the relative content data of EPA+DHA at about 16% by GC.For a better understanding of the chemical substances in these resources, chemical cinstituents of Styela plicata were isolated and identified, and those of Aplidium constellatum have been reported in our previous study Extracts of Styela plicata were isolated and purified by column chromatography on macroporous resin, MCI, silica gel, Sephadex LH-20 gel and HPLC. Mass spectrometry(MS) and nuclear magnetic resonance(NMR) spectroscopic were used to identify structures of those purified compounds. 11 compounds were identified as:(1) cholest-5-ene-3β-alcohol,(2) 4, 8-diene-sphingosine-sixteen carbonate amide,(3) cytosine,(4) 2’-deoxy-uridine,(5) adenosine,(6) guanosine,(7) 2’-deoxythymidine,(8)3-(2-sulfo-ethylamino)-dec-7-enoic acid,(9) tryptophan,(10) 2, 3, 4, 9-tetrahydro-1H-β-carboline-3-carboxylic acid,(11) p-hydroxy-phenylethylamine. Structures of other compounds are still in elucidation.This study could provid a material with two types of major components and a clear background of for successive evaluations of anti-hyperdemic effects and safety. It is expected to not only finally provid a new natural drug for the treatment of cardiovascular disease or new biological resources of functional food, but also make it possible to turning the waste ascidians into treasure.