27 research outputs found
Quality Control of Hypericum perforatum L. Analytical challenges and recent progress
Objectives
The most widely applied qualitative and quantitative analytical methods in the quality control of Hypericum perforatum extracts will be reviewed, including routine analytical tools and most modern approaches.
Key findings
Biologically active components of H. perforatum are chemically diverse, therefore different chromatographic and detection methods are required for the comprehensive analysis of St. John’s wort extracts. Naphthodianthrones, phloroglucinols and flavonoids are the most widely analysed metabolites of this plant. For routine quality control, detection of major compounds belonging to these groups seem to be sufficient, however closer characterisation requires the detection of minor compounds as well.
Conclusions
TLC and HPTLC are basic methods in the routine analysis, whereas HPLC-DAD is the most widely applied method for quantitative analysis due to its versatility. LC-MS is gaining importance in pharmacokinetic studies due to its sensitivity. Modern approaches, such as DNA barcoding, NIRS and NMR metabolomics may offer new possibilities for the more detailed characterization of secondary metabolite profile of Hypericum perforatum extracts
Chemical constituents and antimicrobial activity of the ethanol extracts obtained from the flower, leaf and stem of Salvia officinalis L.
In this paper a comparison of the chemical composition and antimicrobial action of the ethanol extracts from the flower, leaf and stem of the herbal species Salvia officinalis L. (Lamiaceae), originating from the southeast region of Serbia was carried out. The chemical composition of the extracts was determined by GC-FID and GC-MS analyses. Manool has the highest level of all the components (9.011.1 %). Antimicrobial activity was determined by the diffusion and dilution method, whereby the latter one was modified by use of cellulose discs, and it was applied for the determination of the minimal inhibitory (MIC) and minimal lethal concentrations (MLC). The leaf extract has a stronger antimicrobial activity than those of the flower and stem
Syntheses and Properties of Two Heterocyclically Substituted Hypericin Derivatives: 10,11-Dibenzothiazolyl-10,11-didemethylhypericin and 10,11-Dibenzoxazolyl-10,11-didemethylhypericin
Variability of mycophenolic acid elimination in the renal transplant recipients-population pharmacokinetic approach
© 2015 Informa Healthcare USA, Inc. The aim of this study was to develop a population pharmacokinetic (PK) model for clearance of mycophenolic acid (MPA) in adult renal transplant recipients, to quantify the PK parameters and the influence of covariates on the MPA pharmacokinetic parameters. Parameters associated with plasma concentrations of MPA at steady-state were analyzed in 70 renal transplant recipients (mean age 42.97 years; mean total body weight 75.33kg) using nonlinear mixed-effect modeling (NONMEM). Characteristics of patients screened for influence on the pharmacokinetic parameters were gender, age, body weight, time after transplantation, whether the patient was diagnosed as having diabetes mellitus, organ source (living or deceased donor), biochemical parameters and co-therapy (tacrolimus, cyclosporine, prednisolone, omeprazole, bisoprolol, carvedilol, nifedipine). A validation set of 25 renal transplant recipients was used to estimate the predictive performance of population pharmacokinetic model. Typical mean value of MPA oral clearance, estimated by base model (without covariates) was 0.741Lh-1. During population modeling, the full model showed that clearance of the MPA was significantly influenced by age, total daily dose of MPA, creatinine clearance, albumin level, status and gender of a donor, and the nifedipine and tacrolimus co-therapy. In the final model, clearance of MPA was reported to be significantly influenced by age, total daily dose of MPA and thenifedipine co-therapy. The derived model describes adequately MPA clearance in terms of characteristics of our patients, offering basis for individual pharmacotherapy approach