Anti-Epstein-Barr Viral Agents from the Medicinal Herb-Derived Fungus Alternaria alstroemeriae Km2286.

Chromatographic separation on the liquid-state fermented products produced by the fungal strain Alternaria alstroemeriae Km2286 isolated from the littoral medicinal herb Atriplex maximowicziana Makino resulted in the isolation of compounds 1-9. Structures were determined by spectroscopic analysis as four undescribed perylenequinones, altertromins A-D (1-4), along with altertoxin IV (5), altertoxin VIII (6), stemphyperylenol (7), tenuazonic acid (8), and allo-tenuazonic acid (9). Compounds 1-6 exhibited antiviral activities against Epstein-Barr virus (EBV) with EC50 values ranging from 0.17 ± 0.07 to 3.13 ± 0.31 µM and selectivity indices higher than 10. In an anti-neuroinflammatory assay, compounds 1-4, 6, and 7 showed inhibitory activity of nitric oxide production in lipopolysaccharide-induced microglial BV-2 cells, with IC50 values ranging from 0.33 ± 0.04 to 4.08 ± 0.53 µM without significant cytotoxicity. This is the first report to describe perylenequinone-type compounds with potent anti-EBV and anti-neuroinflammatory activities.

Effects of the headspace gas composition on anaerobic biotransformation of o-, m-, and p-toluic acid in sediment slurries.

Composition of the headspace gas affected the biotransformation pattern of toluic acid isomers in anoxic sediment slurries. Under an N2 atmosphere, o- and m-, and p-toluic acid (20-25 mg L(-1)) were biotransformed in 100 days, 77 days, and 148 days, respectively, with a lag period of 50 days, 49 days, and 50 days, respectively. Under a CO2 atmosphere, the same toluic acid isomers were biotransformed by the sediment microorganisms in 16-25 days without a lag period. CO2 thus increased the biotransformation rates. The presence of H2, on the other hand, decreased the biotransformation rates: in most cases, adding H2 gas (5% and 20% to the N2 and CO2 atmospheres, respectively) not only increased the lag period but also decreased the maximum biotransformation rates. These effects were especially noticeable for the N2 atmosphere. Under N2, the maximum biotransformation rates of the toluic acid isomers were in the order o-toluic acid > m-toluic acid > p-toluic acid. However, under CO2, the maximum biotransformation rates were reversed, i.e., p-toluic acid > m-toluic acid > o-toluic acid. The presence of the methanogen inhibitor bromoethanesulfonic acid (BESA) slowed the biotransformation rates of p-toluic acid, and this together with the population dynamics of the acetogenic bacteria in the sediment slurries, suggested that acetogenic bacteria were involved in the degradation pathway. However, their exact role remains unclear.