Grape proanthocyanidins (PAs) play a major role in the organoleptic properties of wine. They are accumulated mainly in grape skin and seeds during the early stages of berry development. Despite the recent progress in the identification of genes involved in PA biosynthesis, the mechanisms involved in subunit condensation, galloylation, or fine regulation of the spatio-temporal composition of gra...

The simulation of enzymatic reactions, using computer models, is becoming a powerful tool in the most fundamental challenge in biochemistry: to relate the catalytic activity of enzymes to their structure. In the present study, various computed parameters were correlated with the natural logarithm of experimental rate constants for the hydroxylation of various substrate derivatives catalysed by ...

Micrococcus sp. strain 12B was isolated by enriching for growth with dibutylphthalate as the sole carbon and energy source. A pathway for the metabolism of dibutylphthalate and phthalate by micrococcus sp. strain 12B is proposed: dibutylphthalate leads to monobutylphthalate leads to phthalate leads to 3,4-dihydro-3,4-dihydroxyphthalate leads to 3,4-dihydroxyphthalate leads to protocatechuate (3...

The effect of discrete esters and ester mixtures on the intestinal stability and absorption of tenofovir disoproxil fumarate (tenofovir DF, an esterase-sensitive prodrug of the antiviral tenofovir) was compared with the effect of strawberry extract, which has been shown to enhance the absorption of the prodrug across Caco-2 monolayers and in rat ileum. In addition, the mechanism of absorption e...

A bacterium was isolated by elective culture with p-hydroxybenzoate as substrate and nitrate as electron acceptor. It grew either aerobically or anaerobically, by nitrate respiration, on a range of aromatic compounds. The organism was identified as a pseudomonad and was given the trivial name Pseudomonas PN-1. Benzoate and p-hydroxybenzoate were metabolized aerobically via protocatechuate, foll...

Cultures of Caulobacter crescentus were found to grow on a variety of aromatic compounds. Degradation of benzoate, p-hydroxybenzoate, and phenol was found to occur via beta-ketoadipate. The induction of degradative enzymes such as benzoate 1,2-dioxygenase, the ring cleavage enzyme catechol 1,2-dioxygenase, and cis, cis-muconate lactonizing enzyme appeared similar to the control mechanism presen...

RebC is a putative flavin hydroxylase functioning together with RebP to carry out a key step in the biosynthesis of rebeccamycin. To probe the mechanism of flavin-based chemistry in RebC, we solved the structure of RebC with reduced flavin. Upon flavin reduction, the RebC crystal undergoes a change in its unit cell dimension concurrent with a 5 A movement of the isoalloxazine ring, positioning ...

BACKGROUND Propolis (bee glue) has been used as a remedy since ancient times. Propolis from unexplored regions attracts the attention of scientists in the search for new bioactive molecules. RESULTS From Iranian propolis from the Isfahan province, five individual components were isolated: the prenylated coumarin suberosin 1, and four terpene esters: tschimgin (bornyl p-hydroxybenzoate) 2, tsc...

The literature concerning the issue of canine sex pheromones includes reports presenting completely conflicting opinions about the chemical composition of the canine urine in the context of semiochemical communication. At present, the predominant report cited by many different authors is the article published in Science in 1979 by Goodwin at al., presenting methyl p-hydroxybenzoate (methyl para...

Obligate alkaliphilic strains, AM31D(T) and AM11D, that utilize benzoate and m-hydroxybenzoate were isolated from soil obtained from Tsukuba, Ibaraki, Japan. The isolates grew at pH 8-10, but not at neutral pH. They were Gram-positive, facultatively anaerobic, straight rods with peritrichous flagella and produced ellipsoidal spores. The isolates reduced nitrate to nitrite and grew in 0-14 % NaC...