A contribution to the elemental profile of the leaf samples of newly developed Cabernet Franc varieties.

The elemental profile of the leaf samples of three Cabernet Franc clone candidates recently developed in Serbia (Nos. 02, 010 and 012) obtained in the last phase of clonal selection was examined within this study by ICP-OES. Optimal content of Al, Fe, Cu and Zn, the metals well known for their links with a number of neurodegenerative disorders including Alzheimer's disease, has actually highlighted the potential of the leaf sample No. 10 to afford a novel food supplement of natural origin possessing well balanced metal ingredients. Furthermore, lower content of some other elements (Cr, Mn, Ni and Pb) thoroughly supports such a claiming. Finally, the most favourable K/Na ratio observed for the aforementioned sample points out its likely cardioprotectivity. However, two other Cabernet Franc clone candidates might also be recommended for breeding in the same or similar viticultural conditions, since all obtained values were below toxic ones for human consumption.

The natural product content of the selected Cabernet Franc wine samples originating from Serbia: a case study of phenolics.

This work aimed to evaluate the content of selected phenolic natural products in the wine samples made of three new Serbian Cabernet Franc clones (Nos. 02, 010 and 012, respectively) and mother vine (used as the relevant standard) during the period 2008-2012. Compared with all other wine samples, the Cabernet Franc wine of the clone No. 010 was found to have the highest total content of polyphenolics (1.85 ± 0.02 g/L) and anthocyanins (178.55 ± 3.75 mg/L). In addition, its Folin-Ciocalteu index (36.86 ± 0.12) stood out among the examined samples. Finally, the same wine was enriched with ellagic and gallic acids (3.44 ± 0.29 and 27.46 ± 0.21 mg/L, respectively), catechin (135.16 ± 6.47 mg/L) and epicatechin (51.33 ± 2.33 mg/L), the natural products known to exert significant lipid-lowering effects. Taken all together, the clone No. 010 developed in Serbia may offer new Cabernet Franc wine with geographical indication.

Quercetin Potently Reduces Biofilm Formation of the Strain Pseudomonas aeruginosa PAO1 in vitro.

This work was focused on in vitro evaluation of anti-biofilm and anti-quorum sensing effects of four selected flavonoid compounds /(+)-catechin, caffeic acid, quercetin and morin/ using the strain Pseudomonas aeruginosa PAO1. At a concentration of 0.5 MIC quercetin was the only compound found to potently reduce both P. aeruginosa biofilm formation (95%) and its twitching motility. The chemical scaffold of quercetin, a common dietary polyphenol, may actually inspire development of novel and more effective medicinal agents targeting P. aeruginosa, the bacterium well known for its resistance.

Further in vitro evaluation of antimicrobial activity of the marine sesquiterpene hydroquinone avarol.

This work extends in vitro screening of antimicrobial activity of the sesquiterpene hydroquinone avarol, a main secondary metabolite of the Mediterranean sponge species Dysidea avara. The antimicrobial activity was in part evaluated by microdilution method against selected bacterial and fungal strains. Additionally, the screening included evaluation of anti-quorum sensing (anti-QS) effects. At a different extent avarol was proven to be active against all the microorganisms tested (MIC 0.002-0.008 mg/mL and MBC 0.004-0.016 mg/mL; MIC 0.004-0.015 mg/mL and MFC 0.008-0.030 mg/mL; respectively). This marine natural product also showed moderate anti-QS effects, reducing Pseudomonas aeruginosa PAO1 biofilm formation (75%), its twitching and protrusions motilities as well as pyocianin production (39%). According to the best of our knowledge, this is the first report both on avarol anti Gram-negative bacterial activity and anti-QS effects.

Heavy metal content of a medicinal moss tea for hypertension.

The content of various heavy metals (arsenic, cadmium, chromium, copper, iron, lead, mercury, nickel, manganese and zinc) in the moss species Rhodobryum ontariense (Kindb.) Kindb. and its tea are presented in this study. Pursuant to the use of this tea in traditional Chinese medicine for hypertension, the aim of this study was to examine its safety in regard to the metals. All heavy metals were determined by adequate EPA methods. The concentrations of all metals for daily intake in its tea were below the safety levels for human consumption. These results indicate the importance of manganese in R. ontariense tea traditionally used for hypertension and other heart disorders.

Influence of the microenvironment of thiol groups in low molecular mass thiols and serum albumin on the reaction with methylglyoxal.

Methylglyoxal (MG), a reactive alpha-oxoaldehyde that is produced in higher quantities in diabetes, uremia, oxidative stress, aging and inflammation, reacts with the thiol groups (in addition to the amino and guanidino groups) of proteins. This causes protein modification, formation of advanced glycated end products (AGEs) and cross-linking. Low molecular mass thiols can be used as competitive targets for MG, preventing the reactions mentioned above. Therefore, this paper investigated how the microenvironment of the thiol group in low molecular mass thiols (cysteine, N-acetylcysteine (NAcCys), carboxymethylcysteine (CMC) and glutathione (GSH)) and human serum albumin (HSA) affected the thiol reaction with MG. The SH group reaction course was monitored by (1)H-NMR spectroscopy and spectrophotometric quantification. Changes in the HSA molecules were monitored by SDS-PAGE. The microenvironment of the SH group had a major effect on its reactivity and on the product yield. The reactivity of SH groups decreased in the order Cys>GSH>NAcCys. CMC did not react. The percentages of the reacted SH groups in the equilibrium state were almost equal, regardless of the ratio of thiol compound/MG (1:1, 1:2, 1:5): 38.1 + or - 0.9%; 38.2 + or - 0.7% and 39.0 + or - 0.8% for Cys; 26.5 + or - 0.6%; 26.6 + or - 2.6% and 27.4 + or - 2.5% for GSH; 10.8 + or - 0.9%; and 11.2 + or - 0.7% and 12.2 + or - 0.9% for NAcCys, respectively. Our results explain why substances containing alpha-amino-beta-mercapto-ethane as a pharmacophore are successful scavengers of MG. In equilibrium, HSA SH reacted in high percentages both with an insufficient amount and with an excess of MG (55% and 65%, respectively). An analysis of the hydrophobicity of the microenvironment of the SH group on the HSA surface showed that it could contribute to high levels of SH modification, leading to an increase in the scavenging activity of the albumin thiol.