The objective of the study was to determine seasonal variation in the concentration of tannins in wild bush tea (Athrixia phylicoides L.) leaves. The BuOH-HCl_Fe reagent was used to analyze condensed tannins, whereas hydrolysable tannin was analyzed using potassium iodate. The absorbance was measured using a spectrophotometer. Significant seasonal variations in both condensed and hydrolysable t...

The tannins are polyphenolic compounds with complex structures formed by the secondary metabolism in various plants. Among the oldest applications of tannins is leather tanning. Tanning properties are due to the ability of these polyphenols to form complexes with proteins. In this study were analysed six different types of commercially polyphenolic extracts by Fourier transform infrared spectro...

Eleven fungal strains (4 Penicillium commune, 2 Aspergillus niger, 2 Aspergillus rugulosa, Aspergillus terricola, Aspergillus ornatus and Aspergillus fumigatus) were isolated, characterized morphologically and by their capacity to degrade tannins. Aspergillus niger Aa-20 was used as control strain. Several concentrations of hydrolysable tannin (tannic acid) were used as sole carbon source. All ...

vegetable tannins are the main factor of tanning in historical leathers. the identification of tannins in vegetable tanned leathers is not only importantin determining chemical characterization, production technology and structural nature of the leather, but it is also efficient at the evaluation of new vegetable tannins for conservation purposes. previous studies have also shown that chemical ...

Hydrolysable tannins, total phenols and flavonoids in Eugenia uniflora leaves were monthly analysed for one year. The results were correlated with climate conditions (rainfall, humidity, cloudiness and mean temperature) through chemometric methods. Principal component analysis revealed high levels of hydrolysable tannins in the rainy season, whereas flavonoids were mainly produced in the dry se...

Plant tannins, including hydrolysable and condensed varieties, are well known antioxidants in medicinal plants, foods, and edible fruits. Their diverse biological properties and potential for disease prevention have been demonstrated by various in vitro and in vivo assays. A number of ellagitannins, the largest group of hydrolysable tannins, have been isolated from dicotyledoneous angiosperms a...

The aim of the present study was to compare the in vitro inhibitory effects on the salivary and pancreatic α-amylases and the in vivo hypoglycemic actions of the hydrolysable tannin from Chinese natural gall and the condensed tannin from Acacia mearnsii. The human salivary α-amylase was more strongly inhibited by the hydrolysable than by the condensed tannin, with the concentrations for 50% inh...

Introduction Recently it has been shown that flavonoids of polyphenolic compounds such as genistein and daidzein isolated from soyfood exert a therapeutic effect on osteoporosis and that they inhibit osteoclast differentiation [1,2]. Moreover, some flavonoids such as quercetin, kaempferol, and condensed tannins such as (-)-epigallocatechin-gallate (EGCG) derived from vegetables, wine, and green...

nanomaterials (nms) are widely used in health and biomedical applications, however, only a few studies investigate their toxic effects.  the present report signifies a contribution to the study of the toxic effects of silver nanoparticles (ag nps)  on   e. coli cells, which is a model organism of anthropogenic pollution. the toxicity of nanoparticles depends on their  chemical and surface prope...