Effects of p-Coumaric Acid on Ruminal Fermetation Parameters in In Vitro Ruminal Cultures

Abstract

Amino acids, the building blocks of proteins are providing fundamental information about metabolic status and early disease diagnosis. For an accurate interpretation of metabolic status, amino acid reference values for healthy humans are required. Most studies have pointed out that, the most accurate, reliable and sensitive tool to evaluate amino acids in bio?luids (blood or urine) is liquid chromatography coupled with mass spectrometry (LC/MS). The aim of this study was to determine and optimize the urine amino acids pro?ile by LC-QTOF (ESI+) MS, comparatively, using two generic samples from a healthy male and female. Urine aminoacids were puri?ied using solid phase extraction, a pre-column derivatization and liquid/liquid extraction according to Ez-Faast kit (Phenomenex). The derivatized samples were analyzed by LC-QTOF-(ESI+)-MS and data were processed by Data Analysis-Extracted Ion Chromatogram software. A number of 16 amino acids were found in both samples, the male urine showed higher values for 10 amino acids (hydroxyproline, alanine, sarcosine, lysine, histidine, tryptophan, leucine, phenylalanine, cysteine and tyrosine), while glutamine and valine were higher in female urine. Most of the amino acids identi?ied were essential amino acids found in both cases like: glutamine, proline, lysine, histidine, valine, tryptophan, leucine and phenylalanine. The main differences between the male vs female aminoacid ?ingerprints of urine were mainly quantitative and not qualitative. The amino acid concentrations ranged from 1.48 nmol/mg creatinine (proline) to 203.13 nmol/mg (histidine). The concentration of amino acids in man were 2 times higher than for female, while the percentages of essential amino acids were similar in both gender