Human colostrum in vitro protein digestion: peptidomics by liquid chromatography-Orbitrap-high-resolution MS and prospection for bioactive peptides via bioinformatics.

Breast milk is known to contain bioactive peptides that are released during digestion, being a major source of bioactive peptides to the new-born, some of which act against invading pathogens. However, the formation of bioactive peptides during digestion of human colostrum remains largely uninvestigated. This study aimed to investigate the formation of peptides during simulated digestion of human colostrum from adult women and to prospect antimicrobial peptides. For this purpose, we used high-resolution MS to monitor the release of peptides during in vitro digestion. Bioinformatics was used for the prospection of antimicrobial activity of peptides. During simulated digestion (oral, gastric and duodenal phases), 2318 peptide sequences derived from 112 precursor proteins were identified. At the end of simulated digestion, casein-derived peptide sequences were the most frequently observed. Among precursors, some proteins were seen for the first time in this study. The resulting peptides were rich in proline, glutamine, valine and leucine residues, providing characteristic traits of antimicrobial peptides. From bioinformatics analysis, seven peptides showed potentially high antimicrobial activity towards bacteria, viruses and fungi, from which the latter was the most prominent predicted activity. Antimicrobial peptides released during digestion may provide a defence platform with controlled release for the new-born.

An NMR-Based Chemometric Strategy to Identify Leishmania donovani Nucleoside Hydrolase Inhibitors from the Brazilian Tree Ormosia arborea.

Nucleoside hydrolases are a strategic target for the development of drugs to treat leishmaniasis, a neglected disease that affects 700 thousand to one million people annually. The present study aimed to identify Leishmania donovani nucleoside hydrolase (LdNH) inhibitors from the leaves of Ormosia arborea, a tree endemic to Brazilian ecosystems, through a strategy based on 1H NMR analyses and chemometrics. The aqueous EtOH extract of O. arborea leaves inhibited LdNH activity by 95%. The extract was fractionated in triplicate (13 in each step, making a total of 39 fractions). Partial least squares discriminant analysis (PLS-DA) was used to correlate the 1H NMR spectra of the fractions with their LdNH inhibitory activity and thus to identify the spectral regions associated with the bioactivity. The strategy aimed at isolating the probable bioactive substances and led to two new A-type proanthocyanidins, linked to a p-coumaroyl unit (1 and 2), which appeared as noncompetitive inhibitors of LdNH (IC50: 28.2 ± 3.0 µM and 25.6 ± 4.1 µM, respectively). This study confirms the usefulness of the NMR-based chemometric methods to accelerate the discovery of drugs from natural products.

Optimization of Aqueous Extraction from Kalanchoe pinnata Leaves to Obtain the Highest Content of an Anti-inflammatory Flavonoid using a Response Surface Model.

INTRODUCTION: The medicinal plant Kalanchoe pinnata is a phenolic-rich species used worldwide. The reports on its pharmacological uses have increased by 70% in the last 10 years. The leaves of this plant are the main source of an unusual quercetin-diglycosyl flavonoid (QAR, quercetin arabinopyranosyl rhamnopyranoside), which can be easily extracted using water. QAR possess a strong in vivo anti-inflammatory activity. OBJECTIVE: To optimize the aqueous extraction of QAR from K. pinnata leaves using a three-level full factorial design. MATERIAL AND METHODS: After a previous screening design, time (x1 ) and temperature (x2 ) were chosen as the two independent variables for optimization. Freeze-dried leaves were extracted with water (20% w/v), at 30°C, 40°C or 50°C for 5, 18 or 30 min. QAR content (determined by HPLC-DAD) and yield of extracts were analyzed. The optimized extracts were also evaluated for cytotoxicity. RESULTS: The optimal heating times for extract yield and QAR content were similar in two-dimensional (2D) surface responses (between 12.8 and 30 min), but their optimal extraction temperatures were ranged between 40°C and 50°C for QAR content and 30°C and 38°C for extract yield. A compromise region for both parameters was at the mean points that were 40°C for the extraction temperature and 18 min for the total time. CONCLUSION: The optimized process is faster and spends less energy than the previous one (water; 30 min at 55°C); therefore is greener and more attractive for industrial purposes. This is the first report of extraction optimization of this bioactive flavonoid. Copyright © 2018 John Wiley & Sons, Ltd.

Phenolic compounds of Brazilian beers from different types and styles and application of chemometrics for modeling antioxidant capacity.

In the present study we aimed at investigating, for the first time, phenolic compounds in Brazilian beers of different types and styles. We also aimed at applying chemometrics for modeling beer's antioxidant capacity as a function of their physicochemical attributes (density, refractive index, bitterness and ethanol content). Samples (n=29) were analyzed by PCA originating five groups, especially according to ethanol contents and bitterness. In general, Group V (alcoholic beers with very high bitterness) presented higher refractive index, bitterness, ethanol and phenolics contents than Groups I (non-alcoholic beers) and II (alcoholic beers with low bitterness). Brazilian beers phenolics profile was distinct from that of European beers, with high contents of gallic acid (0.5-14.7 mg/L) and low contents of ferulic acid (0.2-1.8 mg/L). Using PLS, beer's antioxidant capacity measured by FRAP assay could be predicted with acceptable precision by data of ethanol content and density, bitterness and refractive index values.

Production of Bacillus sphaericus entomopathogenic biomass using brewery residues.

The use of brewery residues--yeast and trub--has been evaluated aiming to minimize the costs of the industrial production of Bacillus sphaericus-based bioinsecticide. Both brewery residues promoted growth and sporulation of the three B. sphaericus strains that were isolated from Brazilian soils (S1, S2, and S20). However, distinct growth and sporulation behaviors were observed in relation to the different nutritional conditions and strain used. The maximum sporulation percentage was obtained through the cultivation of S20 strain in brewery residual yeast. In general, the entomopathogenic biomasses produced showed good results for toxicity to Culex larvae. The minimum values of larvae population (LC50) were observed for the S20 strain grown on yeast brewery residue-containing media. After fermentation, a considerable decrease in the organic material of alternative media was verified, although the residual values were still higher than that considered appropriate for effluent discharge.

Production of Bacillus sphaericus entomopathogenic biomass using brewery residues.

The use of brewery residues--yeast and trub--has been evaluated aiming to minimize the costs of the industrial production of Bacillus sphaericus-based bioinsecticide. Both brewery residues promoted growth and sporulation of the three B. sphaericus strains that were isolated from Brazilian soils (S1, S2, and S20). However, distinct growth and sporulation behaviors were observed in relation to the different nutritional conditions and strain used. The maximum sporulation percentage was obtained through the cultivation of S20 strain in brewery residual yeast. In general, the entomopathogenic biomasses produced showed good results for toxicity to Culex larvae. The minimum values of larvae population (LC50) were observed for the S20 strain grown on yeast brewery residue-containing media. After fermentation, a considerable decrease in the organic material of alternative media was verified, although the residual values were still higher than that considered appropriate for effluent discharge.