.4 Strains Of Marine Fungi And Two Kinds Of Secondary Metabolites Of Marine Animals And Their Anti-tumor Activity Study

Marine microorganisms and invertebrates continue to be an important source of bioactive secondary metabolites. A study on four strains of marine microorganisms and two invertebrates was carried out to investigate the potential anti-tumor and antioxidant compounds. Studies include comparison of microbial metabolites under different culture conditions, selecting aimed strains, fermentation studies, bioassay-guided fractionation, structural elucidation and preliminary evaluation for activities of pure compounds.After careful comparison of microbial metabolites under different culture conditions, the metabolite patterns of two fungal strains exhibited TLC and HPLC profiles very distinct from those of the original strains, such as higher polarity and different UV absorbance. However, their anti-tumor activity remained. So they were chosen as main objects of this thesis. Furthermore, two invertebrates with anti-tumor activity and two marine fungus of Korean coast with antioxidant activity were selected.Large-scale fermentations of the active strains and smash of the invertebrates were performed. Following the bioactivity, compounds were isolated and purified by using solvent extraction, silica gel column, Sephadex LH20, PHPLC and etc. From fungus Penicillium terrestre, 29 compounds (1-29) were isolated; from fungus Aspergillus repens, 7 compounds (30-36) were isolated; from fungus B382, 6 compounds (37-42) were isolated; from fungus B523, 6 compounds (43-48) were isolated; from echinus Temnopleurus hardwickii, 3 compounds (49-51) were isolated; from ascidian Amaroucium constellatum, 9 compounds (52-60) were isolated.By means of physico-chemical properties and spectral analysis (IR, UV, MS, NMR, X-ray, etc.), structures of 60 pure compounds were respectively determined, Among them there are 20 new compounds, including 8 new gentisyl alcohol polymers (1–8), 3 gentisyl alcohol derivatives (12, 18, 19), 5 sorbicillin derivatives (14-17, 20), 1 zearalenone derivative (37), 3 sulfated alkenes (49-51). Furthermore, 1 new natural product (13) was also isolated.In addition, the types of compounds are involved in benzene derivates (9-11,22-29,43,47-48,56-58), sorbicillin derivative (21), steroides (33,34,53), cerebrosides (31-32), alkaloids (30, 35-36), zearalenone derivatives (38-42), anthraquinones (44-46), nucleosides (52, 55, 59-60), glycerol derivative (54). The antitumor activity against several cancer cell lines of the new compounds was assayed by MTT, SRB and flow cytometry methods. Compounds 1-8 all showed inhibitive activity against HL-60, MOLT-4, A-549, and BEL-7402, and compound 6 showed stronger activity than others. In the continuous research, 6 showed moderate inhibitive activity against protein tyrosine kinases (Src and KDR) by ELISA (inhibitive rate 35.9% and 31.8% on concentration 10μM). In addition, compounds 14 and 15 have weak cytotoxicity against HL-60 with IC50= 9.2 and 37.8μM; 14 also has weak cytotoxicity against A-549 with IC50=39.7μM. When evaluated for their radical scavenging activity against DPPH, compounds 1–8, 12 and 13 showed moderate activity(IC50=4.3, 4.6, 4.4, 6.2, 5.2, 4.1, 6.3, 2.6, 8.5 and 9.8μM respectively. They were all stronger than the positive control (ascorbic acid, IC50=17.4μM).Summarily, this work obtained sixty compounds from four strains of marine fungus and two invertebrates. Among them, 20 compounds were identified new and the possible biogenetic pathways of 12 new compounds were given. A series of novel gentisyl alcohol polymers with antitumor and antioxidant activity was reported. The most important, none of the 36 compounds isolated from the new cultural condition was the same as the 22 compounds isolated from the original condition. Studies mentioned above provided novel structures for searching leading antitumor compounds, and gave a good example for the deep development of the active strains.