Development and validation of a sensitive LC-MS/MS method for simultaneous quantification of thirteen steroid hormones in human serum and its application to the study of type 2 diabetes mellitus.

Endogenous steroid hormones with similar structure, poor content and high efficacy are difficult and vital to be quantitatively detected. In this study, a validated method was established for the simultaneous quantification of thirteen steroids in human serum, and applied to the study of type 2 diabetes mellitus (T2DM). An ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of thirteen steroid hormones in human serum, including androstenedione, corticosterone (B), cortisol (F), cortisone, 18-hydroxycortisol (18OHF), 11-deoxycorticosterone, 11-deoxycortisol, pregnenolone, progesterone, 17-hydroxyprogesterone, testosterone, androstanolone and estradiol. Under the optimum conditions, method was achieved with a BEH Shield RP18 column within 18 min. The lower limits of quantitation for steroids were 0.08-7.81 ng/mL. The intra- and inter-day precision for all the analytes were less than 15 %, and the accuracy ranged from -14.19 % to 12.89 % at three quality control levels. The proposed method, indicating high steady and sensitivity, was successfully applied to the quantification of thirteen steroids levels in serum from patients with T2DM and healthy individuals. The serum concentrations of 18OHF and F were significantly increased in the patients compared with the healthy individuals, while B was significantly decreased. The fold change was 1.98, 1.25 and 0.79 respectively. The ratio of 18OHF to B (18OHF/B) exhibited a 2.51-fold increase in T2DM patients and presented a more significant change. 18OHF/B was identified as a prospective serum marker, which deserves further attention.

Tissue and serum metabolomic phenotyping for diagnosis and prognosis of hepatocellular carcinoma.

More than two-thirds of patients with hepatocellular carcinoma (HCC) cannot receive curative therapy and have poor survival due to late diagnosis and few prognostic directions. In our study, nontargeted and targeted metabolomics analyses were conducted by liquid chromatography-mass spectrometry to characterize metabolic features of HCC and identify diagnostic and prognostic biomarker candidate incorporating liver tissue and serum metabolites. A total of 552 subjects, including 432 with liver tissue and 120 with serum specimens, were recruited in China. In the discovery cohort, a series of 138 metabolites were identified to discriminate HCC tissues from matched nontumor tissues. Retinol presented with the highest area under the curve (AUC) of 0.991 and associated with Edmondson grade. In the validation cohort, all metabolites in retinol metabolism pathway were examined and the levels of retinol and retinal in tumor tissue and serum decreased in the order of normal to cirrhosis to HCC of Edmondson Grades I to IV. Retinol and retinal levels could also differentiate between HCC and cirrhosis, with AUCs of 0.996 and 0.994, respectively, in tissue and 0.812 and 0.744, respectively, in serum. The AUC of the combined retinol and retinal panel in serum was 0.852. Univariate and multivariate Cox regression identified this panel as an independent predictor for HCC and showed that low expression of retinol and retinal correlated with decreased survival time. In conclusion, the retinol metabolic signature had considerable diagnostic and prognostic value for identifying HCC patients who would benefit from prompt therapy and optimal prognostic direction.

Development and validation of a rapid, selective, and sensitive LC-MS/MS method for simultaneous determination of D- and L-amino acids in human serum: application to the study of hepatocellular carcinoma.

A validated liquid chromatography-tandem mass spectrometry method was developed for the simultaneous determination of D- and L-amino acids in human serum. Under the optimum conditions, except for DL-proline, L-glutamine, and D-lysine, the enantioseparation of the other 19 enantiomeric pairs of proteinogenic amino acids and nonchiral glycine was achieved with a CROWNPAK CR-I(+) chiral column within 13 min. The lower limits of quantitation for L-amino acids (including glycine) and D-amino acids were 5-56.25 µM and 0.625-500 nM, respectively, in human serum. The intraday precision and interday precision for all the analytes were less than 15%, and the accuracy ranged from -12.84% to 12.37% at three quality control levels. The proposed method, exhibiting high rapidity, enantioresolution, and sensitivity, was successfully applied to the quantification of D- and L-amino acid levels in serum from hepatocellular carcinoma patients and healthy individuals. The serum concentrations of L-arginine, L-isoleucine, L-aspartate, L-tryptophan, L-alanine, L-methionine, L-serine, glycine, L-valine, L-leucine, L-phenylalanine, L-threonine, D-isoleucine, D-alanine, D-glutamate, D-glutamine, D-methionine, and D-threonine were significantly reduced in the hepatocellular carcinoma patients compared with the healthy individuals (P < 0.01). D-Glutamate and D-glutamine were identified as the most downregulated serum markers (fold change greater than 1.5), which deserves further attention in hepatocellular carcinoma research. Graphical abstract Simultaneous determination of D- and L-amino acids in human serum from hepatocellular carcinoma patients and healthy individuals. AA amino acid, HCC hepatocellular carcinoma, LC liquid chromatography, MS/MS tandem mass spectrometry, NC normal control, TIC total ion chromatogram.

Au(I)-catalyzed rearrangement reaction of propargylic aziridine: synthesis of trisubstituted and cycloalkene-fused pyrroles.

A rearrangement reaction of propargylic aziridine, catalyzed by PPh(3)AuCl/AgOTf, forming trisubstituted and cycloalkene-fused pyrroles is described which involves an unusual tandem cyclization/ring-opening/Wagner-Meerwein process. The unique structures of the products demonstrated its potential applications for synthesizing structurally diverse alkaloids.

Gold-catalyzed reaction of enynols by a dimerization-fragmentation process: an expeditious assembly of enyne molecular architecture.

Intermolecular condensation reaction of 1,3,5-triarylenynols catalyzed by gold as Lewis acid was reported for the first time; the products with unique structures have potential applications in materials chemistry, and tandem reaction product has been used to detect mercury ions as an organic molecular probe.

Arylation and vinylation of alkenes based on unusual sequential semipinacol rearrangement/Grob fragmentation of allylic alcohols.

Alkenes can be stereoselectively arylated and vinylated without transition-metal catalyst under mild conditions through an interesting NBS-promoted semipinacol rearrangement and a subsequent unusual NaOH-mediated Grob fragmentation.