Fatty acid analysis of triacylglycerols: Preparation of fatty acid methyl esters for gas chromatography.

A method to prepare fatty acid methyl esters was developed for fatty acid analysis of triacylglycerols by gas chromatography (GC). Triacylglycerols were mixed with methanolic CH3ONa in hexane containing a mid-polar solvent for 10 s at room temperature. Under these conditions, trioleoylglycerol was converted to methyl oleate with an average yield of 99.

pyroGlu-Leu inhibits the induction of inducible nitric oxide synthase in interleukin-1β-stimulated primary cultured rat hepatocytes.

Pyroglutamyl leucine (pyroGlu-Leu), which is a peptide isolated from wheat gluten hydrolysate, has been reported to be a hepatoprotective compound in acute liver failure. In inflamed liver, proinflammatory cytokines including interleukin (IL)-1β and tumor necrosis factor (TNF)-α stimulate the induction of inducible nitric oxide synthase (iNOS). Excess production of nitric oxide (NO) by iNOS is an inflammatory biomarker in liver injury.

Adenosine, a hepato-protective component in active hexose correlated compound: its identification and iNOS suppression mechanism.

Supplementation of active hexose correlated compound (AHCC) improved the prognosis of postoperative hepatocellular carcinoma patients. Excess production of nitric oxide (NO) by inducible NO synthase (iNOS) is an inflammatory biomarker in liver injury. AHCC suppressed iNOS induction in hepatocytes, suggesting that AHCC has a potential liver-protective effect.

Identification of pyroglutamyl peptides in Japanese rice wine (sake): presence of hepatoprotective pyroGlu-Leu.

Japanese rice wine, sake, is made from steamed rice, water, and lactic acid by "multiple parallel fermentation" with mold (Aspergillus oryzae) and yeast (Saccharomyces cerevisiae). Nineteen pyroglutamyl peptides were identified in commercially available sake. Among them, pyroGlu-Leu and pyroGlu-Gln were the major constituents.

Ingestion of low dose pyroglutamyl leucine improves dextran sulfate sodium-induced colitis and intestinal microbiota in mice.

Inflammatory bowel diseases (IBD) are based on chronic inflammation in the gastrointestinal tract. We previously found anti-inflammatory peptide pyroGlu-Leu in the enzymatic hydrolysate of wheat gluten. The objective of present study is to elucidate improvement of colitis by oral administration of pyroGlu-Leu in an animal model.

Identification of a hepatoprotective peptide in wheat gluten hydrolysate against D-galactosamine-induced acute hepatitis in rats.

A hepatoprotective peptide, pyroglutamyl leucine (pyroGlu-Leu), was identified in wheat gluten hydrolysate through an in vivo activity-guided fractionation approach based on D-galactosamine-induced acute hepatitis in rats and fractionation of peptides with large-scale preparative ampholine-free isoelectric focusing. The active acidic fraction predominantly consisted of pyroglutamyl peptides and free pyroglutamic acid. Pyroglutamyl peptides were derivatized with phenyl isothiocyanate after removal of a pyroglutamyl residue by pyroglutamate aminopeptidase.

Identification of food-derived elastin peptide, prolyl-glycine (Pro-Gly), in human blood after ingestion of elastin hydrolysate.

Elastin hydrolysate has apparent beneficial effects, and the food-derived peptide prolyl-glycine (Pro-Gly) is present in human blood after oral ingestion. Following ingestion of elastin hydrolysate (10 g/60 kg body weight) by healthy human volunteers, peripheral blood was used to prepare plasma samples from which peptides were extracted by solid phase extraction and fractionated by size-exclusion chromatography (SEC). Peptides in the SEC fractions were derivatized with phenyl isothiocyanate (PITC) and resolved by reversed phase (RP)-HPLC.