Stability of monacolin K and citrinin and biochemical characterization of red-koji vinegar during fermentation.

Red-koji vinegar is a Monascus -involved and acetic acid fermentation-derived traditional product, in which the presence of monacolin K and citrinin has attracted public attention. In this study, red-koji wine was prepared as the substrate and artificially supplemented with monacolin K and citrinin and subjected to vinegar fermentation with Acetobacter starter. After 30 days of fermentation, 43.0 and 98.1% of the initial supplements of monacolin K and citrinin were decreased, respectively. During fermentation, acetic acid contents increased, accompanied by decreases of ethanol and lactic acid contents and pH values. The contents of free amino acids increased while the contents of other organic acids, including fumaric acid, citric acid, succinic acid, and tartaric acid, changed limitedly. Besides, increased levels of total phenolics in accordance with increased antioxidative potency, α,α-diphenyl-ß-picrylhydrazyl scavenging, and xanthine oxidase inhibitory (XOI) activities were detected. It is of merit that most citrinin was eliminated and >50% of the monacolin K was retained; contents of free amino acids and total phenolics along with antioxidant and XOI activities of the red-koji vinegar were increased after fermentation.

Toxicological and immunomodulatory assessments of botryosphaeran (ß-glucan) produced by Botryosphaeria rhodina RCYU 30101.

Toxicological and immunomodulatory activities of botryosphaeran (BR), a newly emerged ß-glucan that comprises a ß-(1 → 3) backbone and ß-(1 → 6) branched glucose residues were assessed. BR was 1.82 × 10(6) Da (M.W.) estimated by reversely-linear equation constructed by regression of logarithms of standard polysaccharides and their retention times of gel permeation chromatography. Sprague-Dawley rats were daily gavage-administered with BR at doses of 0, 1.25, 12.5, and 125 mg/kg body weight (BW) for 28 d. Serum hematological and biochemical analysis of all treatment were all within normal ranges. Mitogen-stimulated lymphoblastogenesis of spleno-lymphocytes was enhanced by BR at doses of 1.25 and 12.5 mg/kg BW. Through in vitro comparative assessments, RAW 264.7 macrophage (RAW) cells were treated with BR and two commercial ß-glucans, zymosan (ZY) and barley ß-glucan (GB), to characterize their relative immunomodulatory properties. All three ß-glucans stimulated phagocytosis on fluorescence-labeled Escherichia coli. At dose levels from 5 to 200 µg/mL for 24h, nitric oxide produced by BR- and ZY-treated cells were higher than those produced by GB-treated and control groups. BR, ZY but GB also stimulated RAW cells in producing TNF-α. The results demonstrate that BR is toxicologically accepted and features as a potent immunomodulator.