Identification of the Main Intermediate Precursor of l-Ergothioneine Biosynthesis in Human Biological Specimens.

A capillary electrophoresis coupled to tandem mass spectrometry (CE-MS/MS) has been used to make a qualitative determination of hercynine-the main precursor of l-ergothioneine biosynthesis-in some key human biological specimens, such as urine, whole blood, plasma, and saliva. From semiquantitative analysis results, the highest concentrations of hercynine were detected in saliva and whole blood, whereas much lower concentrations were measured in urine and plasma. Whole blood was the biological matrix with the highest concentration of l-ergothioneine followed by plasma, saliva, and urine.

An isotope dilution capillary electrophoresis/tandem mass spectrometry (CE-MS/MS) method for the simultaneous measurement of choline, betaine, and dimethylglycine concentrations in human plasma.

Plasma concentrations of choline, betaine, and dimethylglycine provide valuable information on the flow of methyl groups in key biological processes, particularly during folate deficiency states. We developed a new method to simultaneously measure these analytes in human plasma. Following sample deproteinization using acetonitrile, an aliquot was evaporated to dryness under vacuum to be then taken up by water.

Simultaneous determination of the main amino thiol and thione in human whole blood by CE and LC.

Background: Two precolumn fluorescence derivatization procedures by two different sulfhydryl-reactive iodoacetyl reagents were established to measure simultaneously glutathione and l-ergothioneine in human whole blood by means of CE and LC.

Materials & Methods: Separations were achieved in <5 min on a reverse-phase column (100 mm × 4.6 mm Zorbax Eclipse Plus C18 3.

Human Serum Albumin Increases the Stability of Green Tea Catechins in Aqueous Physiological Conditions.

Epicatechin (EC), epigallocatechin (EGC), epicatechingallate (ECG) and epigallocatechingallate (EGCG) are antioxidants present in the green tea, a widely used beverage whose health benefits are largely recognized. Nevertheless, major physicochemical limitations, such as the high instability of catechins, pose important questions concerning their potential pharmacological use. Recent studies indicate that binding of catechins with plasmatic proteins may modulate their plasma concentration, tissue delivery and biological activity.

Simultaneous determination of aromatic amino acids in human blood plasma by capillary electrophoresis with UV-absorption detection.

Phenylalanine, tyrosine, and tryptophan, also known as aromatic amino acids, are involved in many physiological and pathophysiological conditions and are indicative of the liver and kidney function. In this work, we describe a simple and accurate method for their simultaneous quantification, in a single capillary electrophoresis run. This method requires minimal sample manipulation, no derivatization procedures, and methyl tryptophan as internal standard.

Simultaneous determination of citrulline and arginine in human blood plasma by capillary electrophoresis with ultraviolet absorption detection.

A new capillary electrophoresis method to measure human blood plasma arginine and citrulline levels in a single run without derivatization was established. After adding homoarginine as internal standard, plasma proteins were removed by a 90:10 v/v acetonitrile/ammonia mixture. Arginine and citrulline were detected by an ultraviolet detector at 190 nm and separated in 11.