Nowadays, flavonoids are present in many cosmetic formulations, mainly in the form of plant extracts. The main reason of still increasing popularity of these substances is their beneficial biochemical activity. The main factor affecting activity of flavonoids in the skin is their skin penetration ability. The studies have evidenced that flavonoids from grape leaf extract as well as flavonoids like quercetin, rutin and catechin can migrate through the model lipophilic membrane from aqueous solution. The influence of common hydrophilic cosmetic additives on the permeation profile of flavonoids has been checked. The partition coefficients of examined flavonoids in the octanol-water extraction system were determined. Correlations between permeation coefficients and log P of particular flavonoids were plotted. To determine the mechanism of influence of hydrophilic substances on the permeation profile of flavonoids, the solubility of these compounds was investigated. Studies suggest that the presence of hydrophilic additives causes the increase in the flavonoid solubility that decreases the activity of flavonoids in the vehicle. In such a situation, the driving force for the penetration is reduced and the decrease of permeation coefficient can be observed.

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Old master paintings -A fruitful field of activity for analysts: Targets, methods, outlook Natural products used by ancient artists as components of paintings on canvas and wood, on sculptures, for murals or illuminated manuscripts are presented as potential analytical targets. Analytical methods recommended so far for the identification of binders, inorganic pigments, and organic dyestuffs are reviewed with special emphasis on hyphenated techniques.

A bacterial strain, TI-C3, was isolated and verified to display 498 U mL -1 of anti-tyrosinase activity. Based on morphological, physiological, and chemical analysis, gyr B sequences, and DNA-DNA hybridization analysis, the strain TI-C3 was identified as a strain of Streptomyces hiroshimensis. The antityrosinase activity of the strain was improved to 905 U mL -1 under cultivation, using glucose and malt extract as the sole carbon and nitrogen sources, respectively.