Using thermal desorption electrospray ionization mass spectrometry to rapidly determine antimicrobial preservatives in cosmetics.

RATIONALE: Characterization and quantification of permitted preservatives are important inspections to prevent the overuse of preservatives in authentic formulations. However, the complexity of sample matrices makes preservative determination in cosmetics a tedious process. A rapid analytical strategy to identify preservatives would insure large numbers of products are in compliance with government regulations. METHODS: Thermal desorption electrospray ionization mass spectrometry (TD-ESI-MS) was used to directly detect preservative compounds in authentic formulations without sample pretreatment. The technique employs a metal probe, which was configured for sampling cosmetics in their original states and was inserted in a closed preheated oven to thermally desorb analytes. The desorbed analytes were then carried by a nitrogen gas stream into an ESI plume, where the formed ions were subsequently detected by the mass analyzer. RESULTS: The TD-ESI mass and tandem mass spectra of different classes of preservative standards were rapidly obtained, and the limits of detection were far below the legal limit of their respective concentrations. The preservatives were also directly detected in different types of authentic formulations in the absence of sample preparation, and within a few seconds per sample. Calibration curves for preservatives in four common formulations yielded good linearity in the regulation-allowed range. CONCLUSIONS: Due to its sensitivity, short analysis time, repeatability, and quantitative ability, TD-ESI-MS may serve as a suitable tool for large-scale screening of cosmetic preservatives to assure product safety. Copyright © 2016 John Wiley & Sons, Ltd.

2-(2H-Benzotriazol-2-yl)-6-[(dicyclo-hexyl-amino)-meth-yl]-4-(2,4,4-trimethyl-pentan-2-yl)phenol.

In the title mol-ecule, C(33)H(48)N(4)O, the dihedral angle between the mean planes of the benzotriazole ring system [maximun deviation = 0.038 (2) Å] and the phenol ring is 16.6 (2)°. There is an intra-molecular O-H⋯N hydrogen bond between the phenol and benzotriazole groups.

Hydrocamptothecin promotes the mRNA expression of Wnt signaling inhibitor DKK-1 / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of hydrocamptothecin on the expression of Wnt signaling pathway inhibitor DKK-1 in tumor cells.</p><p><b>METHODS</b>Human HepG2, Hep3B, LoVo and U251 cells were treated with the antitumor drug Hydrocamptothecin. DKK-1 mRNA expression in the cells was detected with RT-PCR, and beta-catenin expression was measured by fluorescence-activated cell sorting (FACS).</p><p><b>RESULTS</b>DKK mRNA in Hep3B, HepG2, LoVo and U251 cells was significantly increased after hydrocamptothecin treatment for 24 h, and the percentage of beta-catenin-positive cells and fluorescence intensity for beta-catenin expression was lowered in the cells after the treatment.</p><p><b>CONCLUSION</b>Hydrocamptothecin promotes mRNA expression of Wnt signaling pathway inhibitor DKK-1 in Hep3B, HepG2, LoVo and U251 cells.</p>

[The antitussive and de-sputum essential substance from the root of Gerbera piloselloides and its analytical compositions].

OBJECTIVE: To study the chemical constituents of the essential substance from the root of Gerbera piloselloides and its antitussive and de-sputum effects. METHOD: The essential substance (G4) was extracted from the root by alcohol and ethyl acetate, then it was separated by silica gel column eluted by the mixture of ethyl acetate and petroleum ether (5:95). Its chemical components were separated and identified by GC-MS. Its antitussive and de-sputum effect was tested by mice. RESULT: 4 main peaks were separated and identified by GS-MS. They are beta-caryophyllene (15.160%), caryophyllene oxide (21.140%), aristolenepoxide (2.673%) and 6-acetyl-2,2-dimethyl-8(3-methyl-2-butenyl)-2H-chromoene (60.077%) respectively. Its antitussive and de-sputum effect was prominent when the mice was given G4 2,000 mg.kg-1 ig. CONCLUSION: Itis the first time that the antitussive and de-sputum essential substance was separated from the root of Gerbera piloselloides and its main compositions were analyzed.