Secondary metabolites of a mangrove endophytic fungus Aspergillus terreus (No. GX7-3B) from the South China Sea.

The mangrove endophytic fungus Aspergillus terreus (No. GX7-3B) was cultivated in potato dextrose liquid medium, and one rare thiophene compound (1), together with anhydrojavanicin (2), 8-O-methylbostrycoidin (3), 8-O-methyljavanicin (4), botryosphaerone D (5), 6-ethyl-5-hydroxy-3,7-dimethoxynaphthoquinone (6), 3ß,5α-dihydroxy-(22E,24R)-ergosta-7,22-dien-6-one (7), 3ß,5α,14α-trihydroxy-(22E,24R)-ergosta-7, 22-dien-6-one (8), NGA0187 (9) and beauvericin (10), were isolated. Their structures were elucidated by analysis of spectroscopic data. This is the first report of a natural origin for compound 6. Moreover, compounds 3, 4, 5, 7, 8 and 10 were obtained from marine microorganism for the first time. In the bioactive assays in vitro, compounds 2, 3, 9 and 10 displayed remarkable inhibiting actions against α-acetylcholinesterase (AChE) with IC50 values 2.01, 6.71, 1.89, and 3.09 µM, respectively. Furthermore, in the cytotoxicity assays, compounds 7 and 10 exhibited strong or moderate cytotoxic activities against MCF-7, A549, Hela and KB cell lines with IC50 values 4.98 and 2.02 (MCF-7), 1.95 and 0.82 (A549), 0.68 and 1.14 (Hela), and 1.50 and 1.10 µM (KB), respectively; compound 8 had weak inhibitory activities against these tumor cell lines; compounds 1, 2, 3, 4, 5, 6 and 9 exhibited no inhibitory activities against them.

Three bianthraquinone derivatives from the mangrove endophytic fungus Alternaria sp. ZJ9-6B from the South China Sea.

Three new bianthraquinone derivatives, alterporriol K (1), L (2) and M (3), along with six known compounds were obtained from extracts of the endophytic fungus Alternaria sp. ZJ9-6B, isolated from the mangrove Aegiceras corniculatum collected in the South China Sea. Their structures were elucidated by one- and two-dimensional NMR spectroscopy, MS data analysis and circular dichroism measurements. Compounds 1, 2 and 3 were first isolated alterporriols with a C-2-C-2' linkage. The crystallographic data of tetrahydroaltersolanol B (7) was reported for the first time. In the primary bioassays, alterporriol K and L exhibited moderate cytotoxic activity towards MDA-MB-435 and MCF-7 cells with IC50 values ranging from 13.1 to 29.1 µM.

[Secondary metabolites of seaweed endophytic fungi ZJ27 in the South China Sea coast].

OBJECTIVE: To study the secondary metabolites of coastal seaweed endophytic fungi ZJ27. METHODS: The compounds were isolated by chromatographic technique. The structures were identified by comprehensive physic-chemical properties and spectral methods. RESULTS: Five compounds were isolated and identified as sclerotiorin (1), ochrephilone (2), 6-((3E, 5E)-5,7-dimethyl-2-methylenenona-3,5-dienyl)-2,4-dihydroxy-3-methylbenzaldehyde (3),(2E,4E)-4,6-dimethylocta-2,4-dienoic acid (4), pencolide (5). CONCLUSION: 11 g of the compound 1 and 66 mg of the compound 2 were isolated from this fungi indicate that it may develop to be medical source microorganism.

Protection of feruloylated oligosaccharides from corn bran against oxidative stress in PC 12 cells.

Feruloylated oligosaccharides (FOs) were prepared by autoclaving corn bran in oxalic acid (0.6%) solution, and their protection effects against oxidative stress in pheochromocytoma cells (PC 12) cells were investigated. The FOs samples, which comprised a mixture of feruloylated mono- and dipentoses with 4.88% bound ferulic acid (FA), as well as xylose, arabinose, galactose, and glucose amounting to 46.43, 40.46, 3.76, and 8.68% of the total sugars, respectively, were prepared by autoclaving the pretreated corn bran in 0.6% oxalic acid and then further separated. Antioxidant activity was tested by 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH) scavenging and oxygen radical absorbance capacity (ORAC) methods. Oxidative stress was induced by H2O2 in PC 12 neuronal cell culture model. The results showed that FOs exhibited higher antioxidant activity than free ferulic acid, with an IC50 value of 11 versus 128 µM for DPPH and an ORAC value of 4.77 versus 2.62 µmol Trolox/µmol. Tetrazolium blue assay showed that the addition of FOs with an FA concentration >50 µM significantly increased cell viability after treatment with H2O2. Flow cytometry analysis showed that the addition of FOs at concentrations of 800, 200, and 50 µM significantly decreased the apoptosis rate at the sub-G0 phase from 37.5 to 12.7, 16.2, and 20.9% (P < 0.01), respectively. FOs also significantly decreased the malonic dialdehyde content and lactate dehydrogenase (LDH) activity, but increased superoxide dismutase activity in PC 12 cells treated with H2O2 and prevented the damage of cellular membranes by decreasing the release of LDH to the cultures. The addition of FA at 800 µM showed an effect similar to that of FOs at 200 µM. Therefore, the FOs prepared from corn bran are potential functional ingredients for protection against oxidative stress.