polyphenol oxidase (ppo) from tomatoes was extracted and partially purified through  (nh4)2so4 precipitation, dialysis and ion exchange chromatography. the activity of polyphenol oxidase was investigated in solanum lycopersicum. spectrophotometric method was used to assay the enzyme activity and the kinetic constants - maximum enzyme velocity (vmax) and michealis - menten constant (km). of the ...

In the title compound, C(17)H(18)O(5), the pyrogallol group is almost coplanar with the mean plane of the attached carbonyl group [dihedral angle of 1.95 (13)°] and makes a dihedral angle of 56.01 (10)° with the other benzene ring. Of the three meth-oxy groups, only one is significantly twisted relative to its attached benzene ring [C-O-C-C torsion angles of 4.0 (5), 3.9 (6) and -106.3 (4)°]. I...

The anhydrate and the stoichiometric tetarto-hydrate of pyrogallol (0.25 mol water per mol pyrogallol) are both storage stable at ambient conditions, provided that they are phase pure, with the system being at equilibrium at aw (water activity) = 0.15 at 25 °C. Structures have been derived from single crystal and powder X-ray diffraction data for the anhydrate and hydrate, respectively. It is n...

Congestive heart failure (HF) is characterized by inadequate nitric oxide (NO) production in the vasculature. Because NO is degraded by oxygen radicals, we hypothesized that NO is degraded faster in HF from inadequate peripheral arterial antioxidant reserves. HF was induced in male Sprague-Dawley rats by left coronary artery ligation. Vascular endothelial function was evaluated by measuring the...

The potential of the product unit neural networks built by using different memetic evolutionary algorithms for the simultaneous determination of mixtures of analytes based on dynamic responses was investigated. For this purpose, three methodologies for obtaining the structure and weights of neural networks were proposed, based on the combination of the evolutionary programming algorithm, a clus...

BACKGROUND Theaflavins including theaflavin (TF), theaflavin-3-gallate (TF3G), theaflavin-3'-gallate (TF3'G), and theaflavin-3,3'-digallate (TFDG), are the most important bioactive polyphenols in black tea. Because of their poor systemic bioavailability, it is still unclear how these compounds can exert their biological functions. The objective of this study is to identify the microbial metabol...

concentration of a sample that gave an absorbance value within the linear range of the assay and was expressed relative to the absorbance/␮g of BSA (corresponding to the gradient of the calibration curve): Interference ϭ absorbance/␮g of aminoglycoside absorbance/␮g of BSA ϫ 100% The aminoglycosides gave negligible interference in the CBB assay (Ͻ0.2% relative to BSA) and failed to generate tur...

In skeletal muscle cells, GLUT1 is responsible for a large portion of basal uptake of glucose and dehydroascorbic acid, both of which play roles in antioxidant defense. We hypothesized that conditions that would decrease GLUT1-mediated transport would cause increased reactive oxygen species (ROS) levels in L6 myoblasts, while conditions that would increase GLUT1-mediated transport would result ...