The sensitivities of oligosaccharide derivatives in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) were compared using two matrixes, 2,5-dihydroxybenzoic acid (DHBA) and alpha-cyano-4-hydroxycinnamic acid (CHCA). For this purpose, maltopentaose was tagged with 2-aminopyridine (PA), 4-aminobenzoic acid ethyl ester (ABEE), and trimethyl-(p-aminophenyl)ammonium chloride (TMAPA). DHBA was more advantageous for enhancement than CHCA. Among the derivatives, the sensitivity with the PA-tagged maltopentaose showed a 100-fold improvement over the native one with DHBA as a matrix, while the oligesaccharide derivatized with ABEE and TMAPA gave 30- and 10-fold increases in sensitivity over the underivatized one. To obtain structural information from these derivatized oligosaccharides, postsource decay (PSD) during flight in the field-free drift in MALDI-TOFMS was measured. Predictable and reproducible fragmentation patterns could be obtained in all cases. Furthermore, we found matrix-dependence fragmentation with the PA-labeled oligosaccharide. With CHCA, a simple spectrum ascribable to Y series ions was obtained. On the other hand, both B and Y series ions were clearly observed in the DHBA case. The results demonstrate the usefulness of derivatives for sensitive analysis of oligosaccharides with MALDI.

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These findings suggest that AN patients have reduced cardiovascular sympathetic nervous responsiveness, increased parasympathetic nervous responsiveness, and increased complexity of the interbeat interval time series compared with healthy controls. Regarding the relationship to prognosis of AN, the study showed conflicting results, and further prospective studies are needed to determine if these results are related to high mortality in AN patients.

BackgroundRosmarinic acid (RA) is a natural substance that may be useful for treating diabetes mellitus. The present study investigated the effects of RA on glucose homeostasis and insulin regulation in rats with streptozocin (STZ)-induced type 1 diabetes or high-fat diet (HFD)-induced type 2 diabetes.MethodsGlucose homeostasis was determined using oral glucose tolerance tests and postprandial glucose tests, and insulin activity was evaluated using insulin tolerance tests and the homeostatic model assessment for insulin resistance. Additionally, the protein expression levels of PEPCK and GLUT4 were determined using Western blot analysis.ResultsRA administration exerted a marked hypoglycemic effect on STZ-induced diabetic rats and enhanced glucose utilization and insulin sensitivity in HFD-fed diabetic rats. These effects of RA were dose-dependent. Meanwhile, RA administration reversed the STZ- and HFD-induced increase in PEPCK expression in the liver and the STZ- and HFD-induced decrease in GLUT4 expression in skeletal muscle.ConclusionRA reduces hyperglycemia and ameliorates insulin sensitivity by decreasing PEPCK expression and increasing GLUT4 expression.