Characterization of a novel PepF-like oligopeptidase secreted by Bacillus amyloliquefaciens 23-7A.

An oligopeptidase from Bacillus amyloliquefaciens 23-7A was characterized along with its biochemical activities and structural gene. The protein's amino acid sequence and enzymatic activities were similar to those of other bacterial PepFs, which belong to metallopeptidase family M3. While most bacterial PepFs are cytoplasmic endopeptidases, the identified PepFBa oligopeptidase is a secreted protein and may facilitate the process of sporulation.

Antioxidant properties of scopoletin isolated from Sinomonium acutum.

Scopoletin was isolated from Sinomonium acutum and studied using four experimental models designed to assess antioxidant properties. The results indicated that scopoletin scavenged superoxide anion in the xanthine/xanthine oxidase reaction system in a concentration-dependent manner, but did not inhibit xanthine oxidase. Scopoletin may therefore be responsible for the superoxide anion scavenging activity seen in Sinomonium acutum extracts and may be of use in preventing superoxide anion-induced damage in vivo.

Purification, characterization, and genetic analysis of a leucine aminopeptidase from Aspergillus sojae.

Extracellular leucine aminopeptidase (LAP) from Aspergillus sojae was purified to protein homogeneity by sequential fast protein liquid chromatography steps. LAP had an apparent molecular mass of 37 kDa, of which approximately 3% was contributed by N-glycosylated carbohydrate. The purified enzyme was most active at pH 9 and 70 degrees C for 30 min.

2,3,4-Trimethyl-5,7-dihydroxy-2,3-dihydrobenzofuran, a novel antioxidant, from Penicillium citrinum F5.

Bioassy-directed fractionation of a culture broth of Penicillium citrinum F5 led to the isolation of a novel antioxidant 2,3,4-trimethyl-5,7-dihydroxy-2,3-dihydrobenzofuran (1), together with gentisic acid (2), and their structures were determined on the basis of spectroscopic data. In the 1,1-diphenyl-picryl-hydrazyl (DPPH) assay system, compounds 1 and 2 showed free radical scavenging activity with IC(20) values of 10.39 and 4.