Trihydroxybenzoic Acid Research Articles

Vanadium metabolism in tunicates: The coordination chemistry of V(III), V(IV), and V(V) with models for the tunichromes

Two isomeric tunichrome model compounds have been prepared from spermidine and trihydroxybenzoic acid. The coordination chemistry of these ligands with V(III), (IV), and (V) are reported. Vanadium(V) is found to undergo rapid reduction to V(IV) in the presence of these ligands, Vanadium(IV) complexes were characterized by optical and EPR spectroscopy as well as elemental analysis and magnetic measurements. Vanadium(III) also reacts rapidly with these ligands, producing what is thought to be a VOV dimer in acidic solution. The biological implications of the coordination chemistry reported herein with respect to vanadium metabolism in ascidians is discussed.

Synthesis of deuterium labelled analogs of the ubiquinone headgroup

AbstractDeuterium labelled analogs of 2,3 ‐ dimethoxy ‐ 5 ‐ methyl ‐ 1,4 ‐ benzoquinone (2,3 ‐ dimethoxy ‐ 5 methyl[2H3] ‐ 1,4 ‐ benzoquinone; 2,3 ‐ dimethyoxy[2H6] ‐ 5 ‐ methyl ‐ 1,4 ‐ benzoquinone; 2,3 ‐ dimethoxy[2H6] ‐ 5 ‐ methyl[2H3] ‐ 1,4 ‐ benzoquinone) were prepared in five steps starting from 3,4,5 ‐ trihydroxybenzoic acid. The proposed synthetic route results in 100% specific labelling and gives good overall yields. Mass spectra of the labelled derivatives will be briefly discussed.

Synthesis and characterization of a series of vanadium-tunichrome B 1 analogs. Crystal structure of a tris(catecholamide) complex of vanadium

Two isomeric tris(pyrogallol) derivatives, have been synthesized with the use of triaminotriethylamine as the molecular skeleton and the 2,3,4 or 3,4,5-isomers of trihydroxybenzoic acid ligand groups. Vanadium(IV) complexes of these ligands have been prepared in 25 and 66% yields, respectively

Separation of dihydroxybenzoic acids and trihydroxybenzoic acids by two-dimensional thin-layer chromatógraphy

Separation of dihydroxybenzoic acids and trihydroxybenzoic acids by two-dimensional thin-layer chromatógraphy

The metabolism of [carboxyl-14C]aspirin in man.

1. [carboxyl-14C]Aspirin has been orally administered to four male volunteers and the urinary metabolites examined by paper chromatography, t.l.c., h.p.l.c. and mass spectrometry. 2. 14C Radioactivity was eliminated rapidly in the urine, 94 to 98% of the dose in the first 24 h and approx. 1% in 24-48 h. 3. The major urinary metabolite was salicyluric acid (56-68% dose). In addition, free salicylic and gentisic acids were also detected as were both the acyl and phenolic glucuronides of salicylate. 4. A phenolic glucuronide of salicyluric acid has also been identified. The importance of this metabolite in relation to analytical methods for salicylphenolic glucuronide determination is discussed. 5. The presence of other di- and tri-hydroxybenzoic acids or gentisuric acid could not be demonstrated.

Modes of Action of Gallic Acid in Suppressing Food Intake of Rats

Gallic acid (3,4,5,trihydroxybenzoic acid) is a naturally occurring polyphenol comprising the major hydrolytic product of tannic acid. Gallic acid and tannic acid were previously shown to suppress food intake of animals to a similar extent. However, the mechanism by which this effect takes place has not been previously reported.Reported here is that the effect of gallic acid on food intake is not mediated entirely through taste aversion or through other gastrointestinal factors, since a continuous daily infusion of a gallic acid solution (18 ml; 2%) resulted in a significant reduction of food intake. The catechol moiety of gallic acid plays an important role in its suppression of food intake since administration of its 4-0 methyl derivative was significantly less effective in suppressing food intake (P < 0.01). The effectiveness of gallic acid in suppressing food intake diminishes with time, indicating adaptation to the consumption of this polyphenol. Propyl gallate is a more potent suppressor of food intake than gallic acid. Adaptation to the consumption of this polyphenol, if it exists at all, is much slower than with gallic acid.gallic acid food intake

Inhibition of brain glutamate decarboxylase by 4,5-dihydroxyisophthalic acid and related compounds.

Hydroxybenzoic and phthalic acids and their related compounds were tested for inhibitory activity to brain glutamate decarboxylase. Of mono-, di-, and trihydroxybenzoic acids, gallic acid was the most inhibitory, giving 50% inhibition at a concentration of 0.17 mM. Dihydroxybenzoic acids were less inhibitory than the trihydroxyacids but more than monohydroxybenzoic acids. Of the phthalic acid-related compounds tested, 4,5-dihydroxyisophthalic acid was the most potent inhibitor, producing 50% inhibition at 0.61 microM. The inhibition of these compounds was competitive with respect to L-glutamate. The Ki values were 0.02, 1.2 and 4.9 microM for 4,5-dihydroxyisophthalic acid, 5-hydroxyisophthalic acid and gallic acid, respectively. When administered intraventricularly to mice, 4,5-dihydroxyisophthalic acid produced a significant decrease in the gamma-aminobutyric acid content of the brain, resulting in induction of convulsions.

RELATION BETWEEN PHENOLIC ACID CONTENT AND STABILITY OF PECANS IN ACCELERATED STORAGE

ABSTRACTEight phenolic acids were isolated from the testa of Stuart pecan kernels and identified by gas‐liquid chromatography‐mass spectrometry (GLC‐MS). Acid quantities decreased significantly during 12 wk of accelerated storage of the kernels at 21°C, 65% RH. High correlations (r = 0.95‐0.97) were obtained between decreases in the dihydroxy and trihydroxy benzoic acids and declines in sensory quality of the kernels, indicating that these compounds are implicated in storage stability. Acids identified by GLC‐MS analyses were gallic, gentisic, vanillic, protocatechuic, p‐hydroxybenzoic, and p‐hydroxyphenylacetic acids. Coumaric and syringic acids were present in trace amounts and were identified primarily by comparison of their retention times with those of authentic compounds on two dissimilar GLC columns. Gallic was the predominant acid and constituted ca 78% of those present.

Immune interferon induction by T-cell mitogens involves different T-cell subpopulations

Recent studies of mitogen-induced DNA synthesis in cells from various lymphoid tissues indicate that certain mitogens may selectively activate specific T-cell subpopulations. Staphylococcal enterotoxin A (SEA) optimally stimulates thymocytes and spleen cells (presumed T1 cells) and phytohemagglutinin P (PHA) optimally stimulates lymph node and spleen cells (presumed T2 cells); concanavalin A (Con A) stimulates cells from all these sources well. To determine further the specificity of mitogens for T-cell subpopulations, immune interferon (IIF) production was studied in spleen cells from mice treated in vivo with cortisone acetate (CA), preferentially a T1-cell inactivator, and antithymocyte serum (ATS), preferentially a T2-cell inactivator. The effect of administering gallic acid (3,4,5 trihydroxy-benzoic acid) (GA) in vivo was also studied, since in vitro studies showed GA to be capable of blocking IIF production. Results indicate that SEA induces IIF primarily in T1 cells, PHA induces IIF primarily in T2 cells, and Con A induces IIF in both T1 and T2 cells. Furthermore, GA was shown to mimic the ability of CA to inactivate T1 cells selectively in vivo. The data indicate that more than one type of T-cell subpopulation is capable of producing IIF.

Chromatographic and spectral analysis of phenolic acids and related compounds

Chromatographic data were obtained for 41 phenolic acids and related compounds by using two gas chromatographic supports and two paper chromatographic and two thin layer chromatographic systems. Spectral maxima in the ultraviolet region and observed characteristics bathochromic shifts were also obtained when aluminum chloride was added. Conversion of the gas chromatographic relative retention values to the Kovaát's indices system permitted an analysis of the effects of substitutents and sites of attachment on retention time. Relative contributions of molecular weight and intra- and intermolecular hydrogen bonding to I k values are discussed. Hydroxy and methoxy substitution of benzene and benzoic and cinnamic acids decreased the R F values in both TLC and PC, with some exceptions. Positional effects were often observed. Aluminum chloride elicited a small bathochromic shift for all acids; larger shifts were observed with dihydroxy and trihydroxybenzoic acids when the substitution pattern permitted chelation.

Conductometric Study of Thallium(I) Chelates of 3,4- Dihydroxy- and 3,4,5 -Trihydroxy-benzoic Acids

Conductometric Study of Thallium(I) Chelates of 3,4- Dihydroxy- and 3,4,5 -Trihydroxy-benzoic Acids

Developer activity of di- and trihydroxybenzoic acids.

Developer activity of di- and trihydroxybenzoic acids.

Abnormal Strength of 2:6-Dihydroxybenzoic Acids

THE work of W. Ostwald1 showed that the electrolytic dissociation constants of the hydroxybenzoic acids vary greatly with the positions of the hydroxyl groups. Thus the dissociation constants of benzoic acid, and of those mono-, di- and tri-hydroxybenzoic acids, which do not possess a hydroxyl group in the ortho-position to the carboxyl group, have dissociation constants all less than 1 × 104; the dissociation constants of the various hydroxybenzoic acids containing an ortho-hydroxyl group are all of the order of 1 × 103, and 2:6-dihydroxybenzoic acid has a dissociation constant of 5.0 × 102 (see Table 1).