The preservation for electron microscopy of saturated phospholipids in general, and phosphatidyl choline (PC)in particular, remains and unsolved problem since OsO(4) and glutaraldehyde are incapable of interacting with PC directly. However, by introducing tannic acid preceding osmication, we were able to demonstrate highly ordered, preserved lamellar structures in model experiments with saturat...

ÐFerron reagent and FTIR spectroscopy were used for the identi®cation and characterization of the aluminum species formed during dephosphorization of simulated wastewater with and without organic matter. Evidence from FTIR spectroscopy showed the formation of aluminum hydroxyphosphate, hydroxy-Al±tannate and aluminum complexes containing both phosphorus and tannic acid. The surface reactivity o...

The purpose of this study was to quantify the degree of suppression of the perceived bitterness of quinine by various substances and to examine the mechanism of bitterness suppression. The following compounds were tested for their ability to suppress bitterness: sucrose, a natural sweetener; aspartame, a noncaloric sweetener; sodium chloride (NaCl) as the electrolyte; phosphatidic acid, a comme...

Endoplasmic reticulum (ER) stress is an intriguing target with significant clinical importance in chemotherapy. Interference with ER functions can lead to the accumulation of unfolded proteins, as detected by transmembrane sensors that instigate the unfolded protein response (UPR). Therefore, controlling induced UPR via ER stress with natural compounds could be a novel therapeutic strategy for ...

A spectrophotometric method is proposed for the determination of the polyphenols content in aqueous extracts of plants. The method is based on the reduction of Cu(II) to Cu(I) by polyphenols, in the presence of bicinchoninic acid in a buffered medium (ammonium acetate, pH 7.0) with the formation of Cu(I)/BCA complexes. A calibration curve of absorbance (at 558 nm) vs tannic acid concentration i...

BACKGROUND AND OBJECTIVES Tannins are toxic polyphenols that either bind and precipitate or condense proteins. The high tannin content of some plants is the preliminary limitation of using them as a ruminant feed. So, the aim of this study was the isolation and characterization of tannic acid degrading bacterial strains from goat feces before and after feeding on Pistachio-Soft Hulls as tannin ...

Unsaturated natural and synthetic phosphatidyl cholines (PCs), when treated with tannic acid and OsO4, demonstrated a substantial increase in contrast as compared to PC treated only with OsO4. This was not observed when phosphatidyl ethanolamine (PEA) was similarly exposed to tannic acid. The increased electron density observed in the lamellar organization of the PC phospholipids was limited to...

Allelochemicals released from root exudates or decaying residues of plants play diversified roles in ecological interactions of plant-pathogen. The objective of this work was to evaluate the allelopathic effect of an externally supplied tannic acid on soil-borne in vitro Fusarium oxysporum f. sp. niveum. Results showed that the tannic acid decreased the growth of the fungus up to 9.5% at 800 mg...

Solutions of tannic (digallic) acid at concentrations of 5 or 50 parts per million reduce dissolved ferric iron to the ferrous state when the pH is less than 4. In solutions with a pH of 4 or more, a black material containing ferric iron and tannic acid is precipitated. In a solution containing 500 parts per million of tannic acid, a ferrous complex forms at a pH of more than 5. This complex is...

Astringent compounds were applied to oral epithelium of the clawed toad, Xenopus laevis, and rapidly rising and highly sensitive responses could be recorded from the whole glossopharyngeal nerve, but not at all from the trigeminal nerve. The response to 10 mM tannic acid decreased progressively with repetitive application. These responses to tannic acid, however, recovered completely by treatin...