| The antioxidant activity of one hundred and seventy-four strains of marine fungi that were isolated from deep-sea sediment and mangrove debris was determined by chemical luminometry in this study. Eight compounds were isolated from the fermentation broth, three of which are novel compounds.The results showed that seven of the strains isolated from deep-sea sediment and one strain that was isolated from mangrove debris had the ability of scavenging H2O2, accounting for 4.60% of the strains tested. Among the seven strains, three had the ability of scavenging H2O2 and OH·. The antioxidant activity of #114, #115 and #134 were further determined by chemical luminometry and DPPH free radical assay. The results suggested that the EAF of the three fungi with the IC50 of 1.92μg/mL,55.55μg/mL and 11.23μg/mL(OH·system);1.45μg/mL,13.79μg/mL and 72.29μg/mL(H2O2 system);and 112.45μg/mL,58.87μg/mL and 169.39μg/mL(DPPH system),respectively, along with the glycans of the three strains, had antioxidant activities.The antioxidant activity of marine bacterium 1202 was also investigated using the 1, 1-Diphenyl-2-picryl-hydrazyl (DPPH) free radical-scavenging assay, the hydrogen peroxide-induced luminol chemiluminescence (CL) assay and hydroxyl free radical- -initiated chemiluminescence (CL) assay. The three water-solvent polysaccharides PI, PII and PIII and the ethyl acetate extraction (EAE) and its five fractions of water (WaF), methanol (MeF), butanol BuF), ethyl acetate (EAF) and (PeF) were prepared and then subjected to antioxidant activity evaluation. All the fractions exerted significant inhibitory effects on hydrogen peroxide and hydroxyl free radical, and with the exception of PI, PII and PIII, all other fractions possessed the DPPH scavenging activities. The EAF showed the highest effects on the DPPH scavenging and the inhibition of hydrogen peroxide-induced CL and hydroxyl free radical- -initiated CL with the IC50 of 35.17μg /m L, 0.05μg /ml and 1.13μg /ml, respectively. The result suggested that the EAF appeared in connection with antioxidant activities. Secondary metabolites from two marine fungi strains and one endophytic fungus from a pharmaceutical plant were observed in this study. The entire region ITS1-5.8s-ITS2 of #114, #115 and SXZ-02 were amplified by PCR. Associated with morphological character, #114, #115 and SXZ-02 were identified as Penicillium SP, Aspergillus oryzae and Phomopsis sp., respectively. Employing different isolation and purification methods, eight compounds were isolated from 114: six of them are 6,9,10-trihydroxy-5,6,9-trimethyl-octahydrobenzo[8]annulene-1,7,8(9H)-trione, 4-methoxybenzoic acid, 2-(4-hydroxyphenyl)acetic acid, methyl 4-hydroxybenzoate, (Z)-1-(2,4-dihydroxy-3,5-dimethylphenyl)hex-4-en-1-one and (2E,4E)-1-(2,6- dihydroxy- 3,5-dimethylphenyl)hexa-2,4-dien-1-one. Compound 115-3 isolated from WP-D-1 is identified as 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one. Five compounds were isolated from the fermentation broth of SXZ-02; one of these is identified as 8-O-acetyl multipolide A.Further more, these compounds were tested for their antimicrobial, antitumor, AchE inhibitory, TYR inhibitory and antioxidant activities. The result showed that AF-1 exhibited inhibitory activity against AChE with the IC50 value at 0.61μg/ml, but it exhibited no evident antifungal activities against Mycobecterium Tuberculosis at 25μg/ml, compared with the positive control galanthamine. And compound of 114-25 showed anti-tumor activity against Hela cell line with IC50 value at 2.64μg/ml.
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