Separation Of Active Compounds From Synechcoocus Sp. And Its Antibacterial And Antioxidative Properties

As the primary producers and main part of marine organism, marine microalgaeplays an important role in material and energy cycle of marine ecosystem which inturn provides a unique living environment for microalgae to produce functionalmetabolin. The research on microalgae active material has been a hotspot with thefound of more and more microalgae active compounds, and that makes marinemicroalgae as a potential resource for the development of new drugs or basic materialof functional food.Synechococcus, a kind of Cyanobacteria, can produce abundant functionalsecondary metabolite during the growth. Therefore, the active compounds of differentpolar from Synechococcus were extracted and separated to trace the antioxidant andantibacterial activities of crude extracted material. The more active parts were furtherpurified according to the results of bioactivity determinition. The molecularidentification was clarified and the bioactivities of compounds were confirmed further.The experiment results were as follows:1、The composition of Synechococcus algae powder was analyzed, and theresults showed there was ash content18.4%, crude protein content12.3%, crude fatcontent16.2%, crude fibre content5.9%, water content35.7%and carbohydratecontent11.5%. Fat content in Synechococcus was a little higher compared to othermicroalgae, making it a potential material for exploitation and development.2、Different polarity solvents were used to extract the freezing and driedSynechococcus algae powder. The results showed that there was more low-polaritymaterial in the Synechococcus than the high-polarity while middle-polarity materialwas the least. After GC-MS analysis on crude extract of every phase, petroleum etherand n-butyl alcohol phase each contained20components. The content of acids is69.9%in petroleum ether phase, and other major material are esters, carbon alkeneand alcohols. The content of Esters was69.9%in n-butyl alcohol phase, and othermajor material were alcohols, acids, alkane and ketone.3、The antibacterial and antioxidant activity of crude extracts were detected totrace the active component. The antibacterial ability of petroleum ether phase wasstronger than that of ethyl acetate and n-butyl alcohol in crude extract. IC50value of the free radical scavenging rate of petroleum ether phase was less than that of ethylacetate and n-butyl alcohol, which indicated a strong antioxidant ability of petroleumether phase. So the petroleum ether phase was further separated.4、Component G1, G2and G3were obtained in the separation of petroleum etherphase. Active tracking results showed that IC50value of G1and G2was292.76μg/mL and346.76μg/mL respectively, therefore G1and G2were further separated.H1and H2were got from G1, N1、N2and N3from G2. Activity analysis resultsindicated good actibity of H1and N1with the IC50value of302.82μg/mL and346.85μg/mL respectively.5、Two monomeric compound S1and S2were separated from H1and N1withthe method of gel Sephadex LH-20. Nuclear magnetic identification showed that S1was β-sitosterol, and that S2was daucosterol.6、Antibacterial activity and antioxidant activity of β-sitosterol and daucosterolwere examined. Antibacterial activity results showed that β-sitosterol had a restrainedeffect on bacillus subtilis, staphylococcus aureus, escherichia coli and mycetozoan.The minimal inhibitory concentration of β-sitosterol for gram-positive bacteria andgram-negative bacteria was7.5mg/mL and3.7mg/mL respectively. But daucosterolhad no bacteriostatic activity. Antioxidant activity was found in both β-sitosterol anddaucosterol. The IC50value of DPPH free radical scavenging rate of β-sitosterol anddaucosterol was372.62μg/mL and334.37μg/mL respectively and the antioxidantcapacity would increase with the increase of concentration. The antioxidant capacityof daucosterol was greater than that of β-sitosterol, which could be concluded fromIC50value.