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- Author or Editor: Wei Yang x
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A high-performance liquid chromatography—diode-array detection method was developed and validated to determine simultaneously eleven major alkaloids in Corydalis decumbens (Thunb.) Pers. The alkaloids detected were corlumidine, protopine, coptisine, tetrahydrojatrorrhizine, palmatine, berberine, sanguinarine, papaverine hydrochloride, tetrahydropalmatine, bicuculline, and corydaline. Chromatographic separation was achieved using a C-18 column with a mobile phase composed of A (0.2% acetic acid solution, adjusted with triethylamine to pH 5.0) and B (acetonitrile), with stepwise gradient elution. Ultraviolet diode-array detection was used; chromatograms were examined at the wavelength of 280 nm. The regression equations showed a good linear relationship between the peak area of each marker and concentration (r = 0.9994–0.9999). The recovery values ranged between 93.66% and 100.54%. The method was fully validated with respect to detection and quantification limits, precision, reproducibility, and accuracy. The described high-performance liquid chromatography (HPLC) method was successfully used for the differentiation and quantification of the eleven major alkaloids in C. decumbens (Thunb.) Pers. and can be considered an effective procedure for the analyses of this important class of natural compounds.
Abstract
SZJ-1207 is an antidepressant natural product with a steroidal structure extracted from Stephanotis mucronata. It is a novel antidepressant candidate molecule and all its pharmacokinetic properties have not been reported. In this pharmacokinetic study in mice following oral administration, an accurate and sensitive UPLC-MS/MS method was established and evaluated to measure SZJ-1207 concentrations in mouse plasma and brain samples. The results provide information regarding the pharmacokinetics of SZJ-1207 as a potential antidepressant.
Abstract
Background
Existing research has demonstrated that problematic smartphone use (PSU) may reflect a composition of heterogeneous symptoms, with individual PSU symptoms uniquely related to predisposing variables. The Big Five personality traits represent one of the most frequently examined predisposing variables in relation to PSU. However, no studies to date have examined the trait-to-symptom association between the Big Five personality traits and PSU. Using a network analysis approach, we aimed to understand: 1) specific pathways linking each of the Big Five personality traits to PSU symptoms and 2) the bridging effects of each Big Five personality trait on the PSU symptom cluster.
Methods
A regularised graphical Gaussian model was estimated among 1,849 Chinese university students. PSU symptoms were assessed with items from the Problematic Smartphone Use Scale. Facets of the Big Five personality traits were assessed with the subscales of the Chinese Big Five Personality Inventory-15. An empirical index (i.e., bridge expected influence) was used to quantify bridge nodes.
Results
Results revealed specific and distinct pathways between the Big Five personality traits and PSU symptoms (e.g., Neuroticism-Escapism/Avoidance, Conscientiousness-Preoccupation and Extraversion-Escapism/Avoidance). Further, Neuroticism showed the highest positive bridge centrality among the Big Five personality traits, while Conscientiousness had the highest negative bridge centrality.
Discussion and conclusions
The current study provided direct empirical evidence concerning specific pathways between the Big Five personality traits and PSU symptoms and highlighted the influential role of Neuroticism and Conscientiousness as potential targets for early detection and treatment of PSU.
Abstract
A sensitive and rapid method using HPLC-MS/MS was developed for the determination of eight glucocorticoids residues in chicken muscle simultaneously by Turbo Flow. The eight glucocorticoids were prednisone, prednisolone, hydrocortisone, methylprednisolone, dexamethasone, betamethasone, beclomethasone and fludrocortisones. Samples were extracted with ethyl acetate and on-line cleaned up through a Turbo Flow solid-phase extraction column without time-consuming pretreatment before HPLC-MS/MS analysis. Sample pretreatment conditions, Turbo Flow conditions and mass spectral parameters were optimized and obtained eight glucocorticoids calibration curves. These curves showed good linearity over the concentration from 0.2 μg/kg to 50 μg/kg with an average recovery from 71.63% to 117.36%. This method could be applied on real samples and provided simple, rapid, sensitive and highly selective analysis, which made it feasible to be adopted in food inspection organizations or carry out quantitative analysis for other banned substance.
Abstract
A reliable LC-MS/MS method for the determination of five bioactive constituents (bilobalide, BLL; ginkgolide A, GLA; ginkgolide B, GLB; ginkgolide C, GLC; rutin) of Ginkgo biloba leaf extracts (GBE) in rat plasma was established, fully validated and applied to an intragastric pharmacokinetic study of a preparation of GBE in rat. Samples were extracted with ethyl acetate. C18 column was selected as analytical column in this method. Mobile phase was water with 0.01% formic acid and acetonitrile. Quantification was performed in negative multiple-reaction monitoring mode. Matrix instability of terpene lactones was noticed and hydrochloric acid was used as a stabilizer. This method showed good precision and accuracy, recovery was reproducible and matrix effect was negligible. Among four terpene lactones, BLL had the highest exposure and the shortest terminal half-life, GLA and GLB had lower exposure and longer terminal half-life, the exposure of GLC was lowest and its terminal half-life was the maximum, and all of them showed rapid absorption. This study provides a reference for determination of terpene lactones and flavonol glycoside prototypes in GBE and offers pharmacokinetic data of flavonol glycoside prototype in GBE.
Abstract
SZJ-1207 is a natural product extracted from Stephanotis mucronata (Blanco) Merr which has significant antidepressant effects in various depression mouse models, without obvious acute toxicity or sedative-hypnotic side effects. The aim of this study was to preliminarily clarify the pharmacokinetic characteristics of SZJ-1207 in rats after a single intragastric and intravenous administration. In this study, sensitive and reliable UPLC-MS/MS quantification methods were established and then successfully applied to the pharmacokinetic study of SZJ-1207 in rats. The linear range of SZJ-1207 were 0.5–400 ng mL−1 in plasma, feaces, bile and 20–4,000 ng mL−1 in urine, respectively (r > 0.99). All methods met the requirements of ICH M10. The results of pharmaconetic study showed that Cmax, AUC(0-t) and AUC(0-∞) had linear relationships with the administered doses in the range of 0.5–4.5 mg kg−1. There was a significant gender difference in the AUC (0-t) of 0.5 and 1.5 mg kg−1 and Cmax of 1.5 mg kg−1 after ig (P < 0.05). The excretion rates of SZJ-1207 were 8.46 ± 4.82% in feces, 1.89 ± 1.08% in urine, and 0.179 ± 0.118% in bile. The oral absolute bioavailability of SZJ-1207 was calculated as 64.64%.
