Rapid determination of 111 anti-infective drugs possibly added in cosmetics using high-performance liquid chromatography-tandem mass spectrometry with scheduled multiple reaction monitoring.

RATIONALE: Illegal addition of anti-infective drugs to cosmetics at low concentrations has been found. The illicit addition of anti-infective drugs encompasses a wide variety of medications. The current sample purification methods are inadequate to detect all these compounds. A sensitive, wide-coverage, and weak-matrix-effect measurement method needs to be established to address this issue. METHODS: Samples were extracted using acetonitrile, diluted 25 times, and then analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to detect 111 anti-infective drugs. The method was validated and assessed for matrix effect before being applied to cosmetic products. RESULTS: The calibration curves for the analytes exhibited a strong correlation coefficient (r > 0.995). The limit of detection ranged from 0.006 to 0.6 mg/kg. Matrix effects were significantly improved after a 25-fold dilution. The method was successfully applied to various cosmetics. Two of 82 samples tested contained lincomycin and miconazole, respectively. CONCLUSIONS: The developed method is quick and reliable to analyze anti-infective drugs in cosmetics, with potential for both qualitative and quantitative analyses. It is a valuable tool for cosmetic research and development, contributing to safer and more effective cosmetic products.

Screening for illegal addition of glucocorticoids in adulterated cosmetic products using ultra-performance liquid chromatography/tandem mass spectrometry with precursor ion scanning.

RATIONALE: The screening for illegal adulteration of glucocorticoids (GCs) in cosmetics is challenging due to the vast variety of potential GCs that are present to improve the declared effects. An effective analytical method to screen illegally added GCs in cosmetics is vital to protect consumers. METHODS: An ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method using precursor ion scanning (PIS) acquisition mode was developed to screen GCs in cosmetics. Forty-seven GCs were investigated to identify their common product ions formed by collision-induced dissociation. Cosmetic samples spiked with GCs were extracted using solid-phase extraction. RESULTS: Four common positive product ions, m/z 121, 135, 147, and 171, were selected for PIS analysis. Limits of detection (LODs) were established for all 47 GCs. The method was validated on spiked samples to ensure its effectiveness in terms of sensitivity and selectivity. Sixty samples were analyzed. Seven GCs were detected in six samples. CONCLUSIONS: An effective screening method using UPLC/MS/MS with PIS acquisition mode was developed and successfully applied to screen for targeted and untargeted GCs in cosmetic samples.

[Structure determination of three novel bile acids from bear bile powder].

A method of LC-QTOF/MS combining with chemical synthesis has been used to determine the structures of three novel bile acids from bear bile powder. Reference substances of tauroursodeoxycholic acid and taurochenodeoxycholic acid were oxidized by pyridinium chlorochromate. The products were analyzed by LC-QTOF/MS. Total 4 products including 3 isomers were predicted and identified according to the PCC oxidation theory and LC-QTOF/MS results. Bear bile powder samples were dissolved by methanol and analyzed by LC-QTOF/MS. Three unknown peaks were found and identified as 2-[[(3beta, 5beta)-3-hydroxy-7, 24-dioxocholan-24-yl]amino]-ethanesulfonic acid, 2-[[(5beta)-3, 7, 24-trioxocholan-24-yl]amino]-ethanesulfonic acid and 2-[[(5beta, 7beta)-7-hydroxy-3, 24-dioxocholan-24-yl]amino]-ethanesulfonic acid, separately, by matching their results with that of oxidation products above.

[Rapid identification of two new isomers in bear bile powder by LC-Q-TOF-MS combined with PCC oxidation].

A rapid method of Liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) combined with pyridinium chlorochromate (PCC) oxidation has been developed to determine chemical structures of two novel isomers in bear bile powder. Derivatives of ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) were semi-synthesized by PCC oxidation, then were analyzed by LC-Q-TOF-MS. Separation was carried out on a reverse column with the mobile phase of acetonitrile-0.1% formic acid (45:55). The data of Q-TOF-MS was acquired by MS, MS/MS, positive and negative modes. Since UDCA and CDCA were stereochemical isomeric at an alcohol position, two oxidation products were same and have been confirmed by LC-Q-TOF-MS. Other two products were also determined based on the PCC oxidation theory. Samples of bear bile powder were dissolved by methanol and measured by LC-Q-TOF-MS. Two unknown peaks were found and identified by matching their retention times and accurate mass spectra ions with PCC oxidation productS. Finally, the structures of two new bile acids in bear bile powder were confirmed as 3alpha-hydroxy-7-oxo-5beta-cholanic acid, 7alpha-hydroxy-3-oxo-5beta-cholanic acid, respectively.

Metabolism and pharmacokinetics of mangiferin in conventional rats, pseudo-germ-free rats, and streptozotocin-induced diabetic rats.

To clarify the role of the intestinal flora in the absorption and metabolism of mangiferin and to elucidate its metabolic fate and pharmacokinetic profile in diabetic rats, a systematic and comparative investigation of the metabolism and pharmacokinetics of mangiferin in conventional rats, pseudo-germ-free rats, and streptozotocin (STZ)-induced diabetic rats was conducted. Forty-eight metabolites of mangiferin were detected and identified in the urine, plasma, and feces after oral administration (400 mg/kg). Mangiferin underwent extensive metabolism in conventional rats and diabetic rats, but the diabetic rats exhibited a greater number of metabolites compared with that of conventional rats. When the intestinal flora were inhibited, deglycosylation of mangiferin and sequential biotransformations would not occur. Pharmacokinetic studies indicated a 2.79- and 2.35-fold increase in the plasma maximum concentration and the area under the concentration-time curve from 0 to 24 h of mangiferin in diabetic rats compared with those for conventional rats, whereas no significant differences were observed between conventional rats and pseudo-germ-free rats. Further real-time quantitative reverse transcription-polymerase chain reaction results indicated that the multidrug resistance (mdr) 1a level in the ileum increased, whereas its level in the duodenum and the mdr1b mRNA levels in the duodenum, jejunum, and ileum decreased in diabetic rats compared with those in conventional rats. With regard to the pseudo-germ-free rats, up-regulated mdr1a mRNA levels and down-regulated mdr1b mRNA levels in the small intestines were observed. The diabetic status induced increased UDP-glucuronosyltransferase (UGT) 1A3, UGT1A8, UGT2B8, and sulfotransferase (SULT) 1A1 mRNA levels and decreased catechol-O-methyltransferase (COMT), UGT2B6, UGT2B12, and SULT1C1 mRNA levels. These results might partially explain the different pharmacokinetic and metabolic disposition of mangiferin among conventional and model rats.

Structure elucidation of in vivo and in vitro metabolites of mangiferin.

The in vivo and in vitro metabolism of mangiferin was systematically investigated. Urine, plasma, feces, contents of intestinal tract and various organs were collected after oral administration of mangiferin to healthy rats at a dose of 200mg/kg body weight. For comparison, mangiferin was also incubated in vitro with intestinal flora of rats. With the aid of a specific and sensitive liquid chromatography coupled with electrospray ionization tandem hybrid ion trap mass spectrometry (LC-ESI-IT-MS(n)), a total of thirty-three metabolites of mangiferin were detected and their structures were tentatively elucidated on the basis of the characteristics of their precursor ions, product ions and chromatographic retention times. The biotransformation pathways of mangiferin involved deglycosylation, dehydroxylation, methylation, glycosylation, glucuronidation and sulfation.