In situ Raman spectroscopy was applied for the analysis of the solution-mediated polymorphic transformation of prasugrel hydrochloride from the metastable form II to the stable form I. The solution concentration during the transition process was monitored by a gravimetric method. The main factors studied were solvent, temperature, solid loading, and agitation speed. Because of the balance between the solubility and the strength of solute−solvent interactions, the transformation rate was highest in ethyl acetate and lowest in butanone at all three temperatures studied (20, 30, and 40 °C). The thermodynamic driving force of the polymorphic transformation from form II to form I was evaluated through solubility measurements of the two forms in ethyl acetate, acetone, and butanone. At increasing temperature, the nucleation induction time and the overall transformation time decreased despite the decreasing driving force. The solid loading seemed to have no effect on the transformation time because of surface nucleation of form I on form II, as determined from the morphology−time profile through polarizing microscope analysis, whereas increasing the agitation rate resulted in a faster polymorphic transformation process. It was confirmed by transformation experiments that the polymorphic transformation from form II to form I is controlled by the nucleation and growth of the stable form I crystal.
This study is the first to report the use of response surface methodology to improve phenolic yield and antioxidant activity of Acer truncatum leaves extracts (ATLs) obtained by ultrasonic-assisted extraction. The phenolic composition in ATLs extracted under the optimized conditions were characterized by UPLC-QTOF-MS/MS. Solvent and extraction time were selected based on preliminary experiments, and a four-factors-three-levels central composite design was conducted to optimize solvent concentration (X1), material-to-liquid ratio (X2), ultrasonic temperature (X3) and power (X4) for an optimal total phenol yield (Y1) and DPPH• antioxidant activity (Y2). The results showed that the optimal combination was ethanol:water (v:v) 66.21%, material-to-liquid ratio 1:15.31 g/mL, ultrasonic bath temperature 60 °C, power 267.30 W, and time 30 min with three extractions, giving a maximal total phenol yield of 7593.62 mg gallic acid equivalent/100 g d.w. and a maximal DPPH• antioxidant activity of 74,241.61 μmol Trolox equivalent/100 g d.w. Furthermore, 22 phenolics were first identified in ATL extract obtained under the optimized conditions, indicating that gallates, gallotannins, quercetin, myricetin and chlorogenic acid derivatives were the main phenolic components in ATL. What’s more, a gallotannins pathway existing in ATL from gallic acid to penta-O-galloylglucoside was proposed. All these results provide practical information aiming at full utilization of phenolics in ATL, together with fundamental knowledge for further research.
Bacterial strains grown in the presence of low concentrations of dimethyl sulfoxide (DMSO) exhibit significant qualitative and quantitative alterations in the production of secondary metabolites. This effect was confirmed for a variety of biosynthetic families, including chloramphenicol (chorismate), thiostrepton (peptide) and tetracenomycin (polyketide), and for natural and recombinant strains of streptomycetes; a similar effect was seen with antibiotic-producing bacilli such as B. circulans. Increase in antibiotic production was not the result of a change in the growth rate of these organisms, since yields of biomass were similar in media with and without DMSO(up to 3%). Wesuggest that the addition of compounds such as DMSOprovides a means of examining the full biosynthetic potential of microbes and might be used to promote secondary metabolite production. The mode of action ofDMSOis not known, but in the cases studied it may act at the level of translation.
BackgroundLow back pain is a common, disabling musculoskeletal disorder in both developing and developed countries. Although often recommended, the potential efficacy of massage therapy in general, and Chinese massage (tuina) in particular, for relief of chronic low back pain (CLBP) has not been fully established due to inadequate sample sizes, low methodological quality, and subclinical dosing regimens of trials to date. Thus, the purpose of this randomized controlled trial (RCT) is to evaluate the comparative effectiveness of tuina massage therapy versus conventional analgesics for CLBP.Methods/DesignThe present study is a single center, two-arm, open-label RCT. A total of 150 eligible CLBP patients will be randomly assigned to either a tuina treatment group or a conventional drug control group in a 1:1 ratio. Patients in the tuina group receive a 20 minutes, 4-step treatment protocol which includes both structural and relaxation massage, administered in 20 sessions over a period of 4 weeks. Patients in the conventional drug control group are instructed to take a specific daily dose of ibuprofen. The primary outcome measure is the change from baseline back pain and function, measured by Roland-Morris Disability Questionnaire, at two months. Secondary outcome measures include the visual analogue scale, Japanese orthopedic association score (JOAS), and McGill pain questionnaire.DiscussionThe design and methodological rigor of this trial will allow for collection of valuable data to evaluate the efficacy of a specific tuina protocol for treating CLBP. This trial will therefore contribute to providing a solid foundation for clinical treatment of CLBP, as well as future research in massage therapy.Trial registrationThis trial was registered with ClinicalTrials.gov of the National Institute of Health on 22 October 2013 (http://NCT01973010).
Anthocyanins, other flavonoids, and phenolic acids belong to a group of plant natural products with antioxidant activity and may play important roles in plant protection against biotic and abiotic stress and in protection against human diseases. In the present study, the Arabidopsis regulatory gene Production of Anthocyanin Pigment 1 (AtPAP1) was expressed in Brassica napus (canola), and its presence enhanced the antioxidant capacity in transgenic leaves up to 4-fold. Transgenic plants had intense purple coloration, cyanidin and pelargonidin levels were enhanced 50-fold, and quercetin and sinapic acid were 5-fold higher. Consistent with these phytochemical and biological changes, expression for most genes in the flavonoid and phenolic acid biosynthetic pathways was also stimulated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.