The objective of this study is to perform the comparative study of the use of jacketed reactor, ultrasound and maceration as extraction methods for the preparation of standardized extracts of "Alternanthera paronychioides" (Amaranthaceae), a Brazilian plant with potential antioxidant activity and antidiabetics. Therefore, ethanol was used as extractive liquid, and different extraction times for the same amount of vegetable powder and extractive liquid. The antioxidant activity in vitro (ORAC-FL assay) of the extracts was evaluated and the chemical characterization of active extracts was analized by way ESI(-)-MS and HPLC-UV-DAD/MS. The results indicate that etanol extracts of "A. paronychioides" has a remarkable antioxidant activity and among the extraction methods tested, the jacketed reactor and especially the ultrasound had the highest yields.
Popularly known as "Yerba mate", Ilex paraguariensis St Hil. (Aquifoliaceae) is a South American plant extensively used to prepare many beverages, with "chimarrão", "terere" and "mate-tea" as three of the most consumed, and the preparations methods, from the plant material process to extraction mode, determines the type of the final beverage. With many health benefits and also cultural and economic relevance, in this work the volatile compounds composition of these three main beverages were analyzed through headspace solid-phase microextraction (HS-SPME) used in combination with gas chromatography–mass spectrometry (GC-MS). Through this technique, 39 main volatile compounds were identified with spectral similarity above 90%. Using Principal Component Analysis (PCA) and Heatmap analysis, the volatile compounds composition was profiled for all the extracts and start material, and a good homogeneity among the replicates was observed, along with similarities between extracts and their start materials, as well as a notorious distinctive clustering of the different Ilex paraguariensis products, all good indications of the capability of the entire methodology used to analyze volatile compounds profiles. Limonene and n-hexanal were found as the main volatile compounds, and their abundances seem to be affected by the extraction modes, mainly due to water temperature and plant drying process. This work successfully compared the volatile profile of "chimarrão", "terere" and "mate-tea" beverages and their start materials using HS-SPME-GC-MS techniques, with the identification of the volatile compounds as well as the impact of the preparation modes in these ones.
The Alternanthera paronychioides has been studied by their notorious anti-glucotoxic activity, however the chemical characterization had not been done yet. With the use of HPLC-UV-DAD and UPLC-ESI-MS/MS the present work allowed to identify four heterosides possibly associated with the anti-glucotoxic activity; Vitexin and Isovitexin, associated with the alpha-glucosidase inhibition, Flavosativaside and Rutin, associated with the aldose-reductase inhibition. The identified substances were quantified and the extraction methodology was optimized. The study allowed to clarify some of the pharmacological bases involved in the therapeutic uses of the specie, until then empirical.
The Pre-mRNA processing factor 4B Kinase is a serine/threonine kinase responsible for the phosphorylation of essentials proteins of the tri-snRNP complex in the B Complex of the spliceosome in mammals¹, being that the overexpression of PRP4K has being associated with certain ovary cancer forms ², Paclitaxel and Carboplatin resistance³. The understanding of the kinase domain is crucial for the ligand-based rational drug design, and our research group have being working with the obtainment of high resolution crystallographic structures of this protein domain. In this work we present some advances in the protein PRP4K kinase domain production and purification, and also the attempts of protein overexpression in mammals cells.
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