Study On Secondary Metabolites Of A Dinoflagellate Amphidinium Sp.from Hainan

Dinoflagellates,also known as dinoflagellates,are single-celled eukaryotes with double flagellates,cell walls,and photosynthetic pigments.Dinoflagellates are widely distributed and are mostly Marine species.Prosulaceae is a genus of Dinoflagellates,widely distributed in the world and found in the South China Sea.Its secondary metabolites mainly include macrolides and long-chain polyketones,which have antitumor,hemolysis and antifungal activities.In this paper,a strain of Dinoflagellum sp.From Hainan was studied.The secondary metabolites were isolated,extracted and identified.Firstly,the algal strain was cultured in a large scale,and 1200L algal liquid was obtained under the suitable growth conditions.After 21 days of growth,the algal liquid was separated from the algal body by means of filtration after the density of algal cells reached 4×105 cells/mL,and 21 g extract was obtained from the algal liquid by macroporous resin column chromatography.After that,12 monomer compounds were isolated by reversed-phase silica gel column chromatography,TLC analysis and HPLC.The structures of these compounds were characterized by high/low resolution mass spectrometry and nuclear magnetic resonance spectroscopy.Two new compounds and 10 known compounds were identified.Ten known compounds are Grasshopper ketone(L-1),N-acetyltryptamine(L-2),N-phenethylacetamide(L-3),P-hydroxybenzaldehyde(L-4),hydroxydihydrobovolide(L-5),N-acetylkynuramine(L-6),stearic acid(L-7),1-hexadecanoyl propan-2,3-Diol(L-8),Loliolide(L-9),Gibbosterol A(L-10).Compounds L-11 and L-12 are new compounds.Compound L-11 is a relatively rare water-soluble sterol,while compound L-12 is a ribose derivative of loliolide.Their relative configurations were determined by NOESY spectrogram analysis.