The realization that p-aminobenzoic acid is essential as a growth factor has stimulated extensive research in the field of antagonists of this essential metabolite. Woods (1940) and Woods and Fildes (1940) reported that yeast contained a substance, identified as p-aminobenzoic acid, that could protect it against the growth inhibiting action of sulfanilamide. Youmans et al. (1947) reported the t...

Three new ursane-type triterpenoids, 3α,6α,30-trihydroxy-ursan-28-oic acid (1), 3α,30-dihydroxy-6-oxo-ursan-28-oic acid (2) and 3α,6α,7α,30-tetrahydroxy-ursan-28-oic acid (3), together with one known triterpenoid, betulinic acid (4), one known anthraquinone, 1,7-dihydroxy-2-methylanthraquinone (5), four known phenols, 1,3,5-trimethoxybenzene (6), p-hydroxybenzoic acid (7), syringic acid (8), is...

The main antioxidants present in plant extracts—quercetin, ?-carotene, gallic acid, ascorbic hydroxybenzoic caffeic catechin and scopoletin—are able to synthesize silver nanoparticles when reacting with a Ag NO3 solution. UV-visible absorption spectrum recorded most of the shows characteristic surface plasmon resonance band nanoparticles. Nanoparticles synthesised ascorbic, hydroxybenzoic, caff...

The metabolite production of lactic acid bacteria (LAB) on silage was investigated. The aim was to compare the production of antifungal metabolites in silage with the production in liquid cultures previously studied in our laboratory. The following metabolites were found to be present at elevated concentrations in silos inoculated with LAB strains: 3-hydroxydecanoic acid, 2-hydroxy-4-methylpent...

Spectrophotometric methods for the determination of total polyphenols and flavonoids are often used because they simple, sensitive, precise. Before using these methods, must be validated to ensure quality obtained data prove that method is suitable its purpose. The aim this study was validate spectrophotometric flavonoids. has been according polyphenol standards, which belong groups phenolic ac...

new biodegradable network polymers containing siloxane-linked polymeric prodrugs of 5-ammino-2-hydroxybenzoic acid (5-asa) in the main chain were prepared by ter polymerization of methacrylic acid (ma), 2-hydroxyethylmethacrylate (hema), and bis (trimethylsilyloxy) methylsilane (vbm) in the presence of some new cross-linking agents.the monomers and polymers were characterized by ft-ir and 1h-nm...

An arylamine N-acetyltransferase (NAT) responsible for the N acetylation of exogenous 3-amino-4-hydroxybenzoic acid in Streptomyces griseus was identified and characterized. This enzyme was distinct from other eukaryotic and bacterial NATs in that it acetylated various 2-aminophenol derivatives more effectively than it acetylated 5-aminosalicylic acid, and thus it may be involved in the metabol...

The ultrasound-assisted extraction of phenolic compounds from Epimedium brevicornu Maxim was modeled using response surface methodology. A Central Composite Design (CCD) was employed to optimize three extraction variables, including ethanol concentration (X 1), extraction time (X 2), and ratio of aqueous ethanol to raw material (X 3), for the achievement of high extraction yield of the phenolic...