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Taking in consideration the global analysis of complex samples, proposed by the metabolomic approach, the chromatographic fingerprint encompasses an attractive chemical characterization of herbal medicines. Thus, it can be used as a tool in quality control analysis of phytomedicines. The generated multivariate data are better evaluated by chemometric analyses, and they can be modeled by classification methods. 'Stone breaker' is a popular Brazilian plant of Phyllanthus genus, used worldwide to treat renal calculus, hepatitis, and many other diseases. In this study, gradient elution at reversed-phase conditions with detection at ultraviolet region were used to obtain chemical profiles (fingerprints) of botanically identified samples of six Phyllanthus species. The obtained chromatograms, at 275 nm, were organized in data matrices, and the time shifts of peaks were adjusted using the Correlation Optimized Warping algorithm. Principal Component Analyses were performed to evaluate similarities among cultivated and uncultivated samples and the discrimination among the species and, after that, the samples were used to compose three classification models using Soft Independent Modeling of Class analogy, K-Nearest Neighbor, and Partial Least Squares for Discriminant Analysis. The ability of classification models were discussed after their successful application for authenticity evaluation of 25 commercial samples of 'stone breaker.' [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The treatment of diseases using enzymes as targets has called for the development of new and reliable methods for screening. The protease cathepsin D is one such target involved in several diseases such as tumors, degenerative processes, and vital processes of parasites causing schistosomiasis. Herein, we describe the preparation of a fused silica capillary, cathepsin D (CatD)-immobilized enzyme reactor (IMER) using in a multidimensional High Performance Liquid Chromatography-based method (2D-HPLC) and zonal affinity chromatography as an alternative in the search for new ligands. The activity and kinetic parameters of CatD-IMER were evaluated by monitoring the product MOCAc-Gly-Lys-Pro-Ile-Leu-Phe (P-MOCAc) ( K M  = 81.9 ± 7.49 μmol/L) generated by cleavage of the fluorogenic substrate MOCAc-Gly-Lys-Pro-Ile-Leu-Phe-Phe-Arg-Leu-Lys(DNP)- d -Arg-NH2 (S-MOCAc). Stability studies have indicated that CatD-IMER retained 20% of activity after 5 months, a relevant result, because proteases are susceptible to autoproteolysis in solution assays with free enzyme. In the search for inhibitors, 12 crude natural product extracts were analyzed using CatD-IMER as the target, resulting in the isolation of different classes of natural products. In addition, 26 compounds obtained from different species of plants were also screened, demonstrating the efficiency and reproducibility of the herein reported assay even in the case of complex matrices such as plant crude extracts. [ABSTRACT FROM AUTHOR]

Highlights: [•] HsPNP was immobilized onto OT-, epoxy-silica and epoxy-polymeric monolithic capillaries. [•] Kinetic parameters of the immobilized enzyme on the three supports were determined. [•] A screening assay by FAC-MS was carried out on the three capillaries. [•] The obtained affinity order was confirmed by individual K d measurements. [•] HsPNP-monolithic capillary represents a valuable tool to identify new PNP inhibitors. [Copyright &y& Elsevier]

Abstract: Kielcorins are xanthonolignoids with protein kinase C inhibition and antitumor activities. Four racemates were enantioresolved at a multimilligram scale on tris-3,5-dimethylphenylcarbamate amylose phase using polar organic conditions as mobile phase. The low-solubility of these compounds conditioned the injection amount and consequently the productivity. A solid-phase injection system was developed to increase the production rate of the semipreparative process. The effects of the racemates and the related enantiomers on the in vitro growth of human breast cancer cell line MCF-7 were compared. Differences in their growth inhibitory activity were observed. [Copyright &y& Elsevier]

Abstract: The hydroalcoholic extract, prepared from authentic chopped barks of Trichilia catigua, was evaluated by high-performance liquid chromatography using a diode array detector (200–400mn). The crude extract was purified by rotation locular counter-current chromatography and the chloroform fraction obtained was clean-up by solid-phase extraction. With the aim of getting preliminary structure information on-line, the methanol fraction thus obtained was analyzed by gradient elution using the diode array detector coupled to a mass spectrometer. The presence of flavalignan in this extract was inferred by the chromatographic band, in the total ion current trace, that had an [M–H]− =451. With this information, cinchonain Ib was isolated as a pure compound from the crude hydroalcoholic extract using a solid-phase extraction procedure for the sample clean-up followed by a semi-preparative separation using the reverse mode of elution. The isolated compound, after complete characterization, was used as an external standard for the development and validation of a method for the analysis of this compound in herbal medicines using the ultraviolet as the detector. The validated method has been successfully applied for quantification of cinchonain Ib in commercialized herbal medicines sold as Catuaba in Brazil and also in standard chopped barks of T. catigua. [Copyright &y& Elsevier]

Abstract: 20-Hydroxyecdysone (20E) is effective in stimulating protein synthesis, therefore, it has been largely used as anabolic agent in several commercial formulas. Phytochemical study of methanolic extract of twigs from Vitex polygama, used in traditional Brazilian medicine as emenagogue, yielded a large quantity of 20E. This finding led us to developing and validating a simple and reliable method to determine 20E in the surveyed extract. Chromatographic separation of 20E was achieved on a phenyl-hexyl-based column using reversed elution mode. Extract was cleaned-up by solid phase extraction employing C18 cartridge, and an absolute recovery of 97% was acquired. External standard and standard addition calibration graphs were obtained and good linearity was accomplished (r >0.999 for both curves). The limit of quantification and detection were determined. The results for accuracy fell within the −5 to +7% range. [Copyright &y& Elsevier]