Wang Changyun

Chemical defensive substances of soft corals and gorgonians

Abstract Despite lack of efficient physical protection in the highly competitive and hostile environment, the marine invertebrates including soft corals and gorgonians can survive, mainly relying on their chemical defensive system by a series of secondary metabolites accumulating in their bodies or releasing to their surroundings. The chemical defensive functions of these secondary metabolites were found to serve as antipredatory, antimicrobial, allelopathy and antifouling agents. Study on chemical defensive substances from corals and gorgonians is one of the most important topics in marine chemical ecology. The research results could help us to understand the chemical ecological relationships between corals and their surrounding organisms. The research strategy and methodology played an enlightening role in the discovery of bioactive natural products and the generation of new drug lead compounds from marine sources. The chemical defensive substances from soft corals and gorgonians were reviewed. This review focused on the structures of these secondary metabolites as well as their functions including antipredatory, allelopathy and antifouling activities.

Extraction, Fractionation, and Chemical Characterisation of Fucoidans from the Brown Seaweed Sargassum pallidum

Liu X., Liu B., Wie X.L., Sun Z.L., Wang C.Y. (2016): Extraction, fractionation, and chemical characterisation of fucoidans from the brown seaweed Sargassum pallidum. Czech J. Food Sci., 34: 406–413. The fucoidans were obtained by extraction with water and gradient precipitation with different concentrations of ethanol. The main structural characterisations and bioactivities were achieved. Four fractions of water-soluble crude fucoidans with different molecular weights – SPC60, SPC70, SPH60, SPH70 – were extracted from S. pallidum collected from the Yellow Sea, China, using cold water and hot water extraction, and fractional precipitation with gradient concentrations of ethanol. Chemical analysis demonstrated that all of these fucoidan fractions consisted of fucose, rhamnose, xylose, mannose, glucose, and galactose with different monosaccharide mole ratios. Fractions SPC60, SPC70, and SPH70 showed moderate cytotoxic activity against P388 murine leukaemia cells. Fucoidan is a kind of bioactive polysaccharide from the brown algae. This study provides a fast and feasible method to obtain fucoidans from S. pallidum, which can be used as pharmaceutical material and functional food.

Growth inhibition to three red tide microalgae by extracts of Ulva pertusa

Growth inhibition effect of different concentration of distilled water extract and four polar organic solvent (methanol, acetone, ether and chloroform) extracts ofUlva pertusa on three typical red tide microalgae (Heterosigma akashiwo, Alexandrium tamarense andProrocentrum micans) were investigated. Liquid-liquid fractionation and HPLC analysis for methanol extract ofU. pertusa were carried out. Growth of the three microalgae was significantly inhibited by the distilled water extract ofU. pertusa at relatively higher concentration. However, the cells of the three microalgae did not die completely even at high concentration. Methanol extract ofU. pertusa showed the highest growth inhibition on the three microalgae, and all the cells of the three microalgae were killed at relatively high concentration. The other three organic solvent extracts ofU. pertusa had no apparent effect on the three microalgae. The results of bioassays and HPLC analysis suggested that the inhibitory substances inU. pertusa to the microalgal growth had relatively high polarities.H. akashiwo was the most sensitive one whileA. tamarense was the most tolerant one to the growth inhibitory substances.

Studies on the antitumor activity and isolation of the glycoprotein from the gonad ofChlamys (Azumapecten) farreri

After being degreased with acetone, the female gonad ofChlamys (Azumapecten) farreri was extracted with water, and then subjected to DEAE—cellulose column chromatography and purified by Sephadex G-100 chromatography to obtain a pure female gonad glycoprotein (FGGP). The IR spectra, electrophoresis and chemical analysis of FGGP indicated that it was a kind of acid glycoprotein and that the content of total protein and sugar were 54.8% and 40%, respectively. Pharmacological tests showed that FGGP could inhibit (inhibition rate of 40.87%) the growth of Sarcoma 180 of mice.