共0篇 平均IF=NaN (-) 更多分析

    加载中

    logo
    Analysis of docosanol using GC/MS: Method development, validation, and application to human skin permeation studies. Journal of pharmaceutical analysis Docosanol is the only US Food and Drug Administration (FDA) approved over-the-counter topical product for treating recurrent oral-facial herpes simplex labialis. Validated analytical methods for docosanol are required to demonstrate the bioequivalence of docosanol topical products. A gas chromatography/selected ion monitoring mode mass spectrometry (GC/SIM-MS) method was developed and validated for docosanol determination in biological samples. Docosanol and isopropyl palmitate (internal standard) were separated on a high-polarity GC capillary column with (88% cyanopropy)aryl-polysiloxane employed as the stationary phase. The ions of 83 and 256 were selected to monitor docosanol and isopropyl palmitate, respectively; the total run time was 20 min. The GC/SIM-MS method was validated in accordance with US FDA guidelines, and the results met the US FDA acceptance criteria. The docosanol calibration standards were linear in the 100-10000 ng/mL concentration range ( >0.994). The recoveries for docosanol from the receptor fluid and skin homogenates were >93.2% and >95.8%, respectively. The validated method was successfully applied to analyze ex vivo human cadaver skin permeation samples. On applying Abreva® cream tube and Abreva® cream pump, the amount of docosanol that penetrated human cadaver skin at 48 h was 21.5 ± 7.01 and 24.0 ± 6.95 ng/mg, respectively. Accordingly, we concluded that the validated GC/SIM-MS was sensitive, specific, and suitable for quantifying docosanol as a quality control tool. This method can be used for routine analysis as a cost-effective alternative to other techniques. 10.1016/j.jpha.2021.08.004
    Metabolomics-based comparative analysis of the effects of host and environment on metabolites and antioxidative activities. Journal of pharmaceutical analysis (Kom.) Nakai is a well-known medicinal hemiparasite widely distributed in Asia. The synthesis and accumulation of its metabolites are affected by both environmental factors and the host plants, while the latter of which is usually overlooked. The purpose of this study was to comprehensively evaluate the effects of host and habitat on the metabolites in through multiple chemical and biological approaches The metabolite profile of harvested from three different host plants in two habitats were determined by multiple chemical methods including high-performance liquid chromatography-ultraviolet (HPLC-UV), gas chromatography-flame ionization detector (GC-FID) and ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-QTOF/MS). The differences in antioxidant efficacy of were determined based on multiple in vitro models. The multivariate statistical analysis and data fusion strategy were applied to analyze the differences in metabolite profile and antioxidant activity of . Results indicated that the metabolite profile obtained by various chemical approaches was simultaneously affected by host and environment factors, and the environment plays a key role Meanwhile, three main differential metabolites between two environment groups were identified. The results of antioxidant assay indicated that the environment has greater effects on the biological activity of than the host. Therefore, we conclude that the integration of various chemical and biological approaches combined with multivariate statistical and data fusion analysis, which can determine the influences of host plant and habitat on the metabolites, is a powerful strategy to control the quality of semi-parasitic herbal medicine. 10.1016/j.jpha.2021.04.003
    Systematic screening and structural characterization of dipeptides using offline 2D LC-LTQ-Orbitrap MS: A case study of . Journal of pharmaceutical analysis () is a widely used and highly valuable traditional Chinese medicine. Several dipeptides have been detected in , but current scientific knowledge of its chemical makeup remains limited. In this study, an improved approach that integrates offline two-dimensional liquid chromatography (2D LC) separation, precursor ion list, library screening, and diagnostic ion filtering was established to systematically screen and characterize dipeptides in . Offline 2D LC integrating hydrophilic interaction LC and reverse phase separations was established to eliminate interference and identify the target dipeptides. A library containing the potential 400 dipeptides was created, and a precursor ion list with all theoretical precursor ions was adopted to trigger the MS/MS scan with high sensitivity. To identify dipeptides, the type and connection sequence of amino acids were determined according to the product ions. Ile and Leu residues were differentiated for the first time according to the characteristic ion at 69.07. Ultimately, 170 dipeptides were identified or tentatively characterized from , and most are reported for the first time in this species herein. In addition, the identified dipeptides were also applied for discrimination among the three species, and 11 markers were identified. The obtained results provide a deeper understanding of the chemical basis of 10.1016/j.jpha.2021.07.007