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PubMed2004

Hydroxybenzoic acid derivatives in a nonhost rutaceous plant, Orixajaponica, deter both oviposition and larval feeding in a rutaceae-feeding swallowtail butterfly, Papilio xuthus L.

A Rutaceae-feeding swallowtail butterfly. Papilio xuthus L., feeds on various rutaceous plants but always rejects Orixa japonica Thunb. (Rutaceae). Females were strongly deterred from laying eggs by a methanolic extract of O. japonica leaves. Larvae also rejected a diet leaf medium impregnated with O. japonica leaf extracts. Several components in the water-soluble fraction of the leaf extract were found to deter both oviposition and feeding responses. Two major deterrent compounds were characterized as 5-[[2-O-(beta-D-apiofuranosyl)-beta-D-glucopyranosyl]oxy]-2-hydroxybenzoic acid and adisyringoyl aldaric acid. These compounds induced potent deterrence of both oviposition and larval feeding by P. xuthus, which suggests a congruent chemosensory mechanism of allomonal chemicals acting on both female tarsal chemoreceptors and larval maxillary taste receptors.

Animals↗
PubMed1993

Five new prenylated p-hydroxybenzoic acid derivatives with antimicrobial and molluscicidal activity from Piper aduncum leaves.

Five new prenylated benzoic acid derivatives, methyl 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxybenzoate (1), 1-(1-methylethyl)-4-methyl-3-cyclohexenyl 3,5-bis(3-methyl-2-butenyl)-4-hydroxybenzoate (2), 1-(1-methylethyl)-4-methyl-3-cyclohexenyl 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoate (3), methyl 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoate (4), and 4-hydroxy-3-(3-methyl-2-butenyl)-5-(3-methyl-2-butenyl)-benzoic acid (5) were isolated from the dried leaves of Piper aduncum L. (Piperaceae). Together with the new metabolites, four known prenylated benzoic acid derivatives, 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoic acid (6), 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoic acid (nervogenic acid, 7), methyl 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoate (8), and methyl 4-hydroxy-3-(3-methyl-2-butenyl)-benzoate (9) as well as, dillapiol (10), myristicin, and the three sesquiterpenes humulene, caryophyllene epoxide, and humulene epoxide were isolated. Compounds 7, 8, and 9 are reported as natural products for the first time. The structures of the isolates were elucidated by spectroscopic methods, mainly 1D-and 2D-NMR spectroscopy. Isolates 4-7, 9, and 10 were molluscicidal while 2, 5-7, and 9 displayed significant antibacterial activities.

Anti-Infective Agents↗
PubMed1998

3-Amino-5-hydroxybenzoic acid synthase, the terminal enzyme in the formation of the precursor of mC7N units in rifamycin and related antibiotics.

The biosynthesis of ansamycin antibiotics, like rifamycin B, involves formation of 3-amino-5-hydroxybenzoic acid (AHBA) by a novel variant of the shikimate pathway. AHBA then serves as the starter unit for the assembly of a polyketide which eventually links back to the amino group of AHBA to form the macrolactam ring. The terminal enzyme of AHBA formation, which catalyzes the aromatization of 5-deoxy-5-amino-3-dehydroshikimic acid, has been purified to homogeneity from Amycolatopsis mediterranei, the encoding gene has been cloned, sequenced, and overexpressed in Escherichia coli. The recombinant enzyme, a (His)6 fusion protein, as well as the native one, are dimers containing one molecule of pyridoxal phosphate per subunit. Mechanistic studies showed that the enzyme-bound pyridoxal phosphate forms a Schiff's base with the amino group of 5-deoxy-5-amino-3-dehydroshikimic acid and catalyzes both an alpha, beta-dehydration and a stereospecific 1,4-enolization of the substrate. Inactivation of the gene encoding AHBA synthase in the A. mediterranei genome results in loss of rifamycin formation; production of the antibiotic is restored when the mutant is supplemented with AHBA.

Actinobacteria↗
PubMed2001

Mutational analysis and reconstituted expression of the biosynthetic genes involved in the formation of 3-amino-5-hydroxybenzoic acid, the starter unit of rifamycin biosynthesis in amycolatopsis Mediterranei S699.

To investigate a novel branch of the shikimate biosynthesis pathway operating in the formation of 3-amino-5-hydroxybenzoic acid (AHBA), the unique biosynthetic precursor of rifamycin and related ansamycins, a series of target-directed mutations and heterologous gene expressions were investigated in Amycolatopsis mediterranei and Streptomyces coelicolor. The genes involved in AHBA formation were inactivated individually, and the resulting mutants were further examined by incubating the cell-free extracts with known intermediates of the pathway and analyzing for AHBA formation. The rifL, -M, and -N genes were shown to be involved in the step(s) from either phosphoenolpyruvate/d-erythrose 4-phosphate or other precursors to 3,4-dideoxy-4-amino-d-arabino-heptulosonate 7-phosphate. The gene products of the rifH, -G, and -J genes resemble enzymes involved in the shikimate biosynthesis pathway (August, P. R., Tang, L., Yoon, Y. J., Ning, S., Müller, R., Yu, T.-W., Taylor, M., Hoffmann, D., Kim, C.-G., Zhang, X., Hutchinson, C. R., and Floss, H. G. (1998) Chem. Biol. 5, 69-79). Mutants of the rifH and -J genes produced rifamycin B at 1% and 10%, respectively, of the yields of the wild type; inactivation of the rifG gene did not affect rifamycin production significantly. Finally, coexpressing the rifG-N and -J genes in S. coelicolor YU105 under the control of the act promoter led to significant production of AHBA in the fermented cultures, confirming that seven of these genes are indeed necessary and sufficient for AHBA formation. The effects of deletion of individual genes from the heterologous expression cassette on AHBA formation duplicated the effects of the genomic rifG-N and -J mutations on rifamycin production, indicating that all these genes encode proteins with catalytic rather than regulatory functions in AHBA formation for rifamycin biosynthesis by A. mediterranei.

Actinomycetales↗
PubMed1989

Occurrence and content of hydroxycinnamic and hydroxybenzoic acid compounds in foods.

Phenolic acid compounds seem to be universally distributed in plants. They have been the subject of a great number of chemical, biological, agricultural, and medical studies. Hydroxycinnamic acid compounds occur most frequently as simple esters with hydroxy carboxylic acids or glucose, while the hydroxybenzoic acid compounds are present mainly in the form of glucosides. Furthermore, phenolic acids may occur in food plants as esters or glycosides conjugated with other natural compounds such as flavonoids, alcohols, hydroxyfatty acids, sterols, and glucosides. Also, hydroxycinnamic acid amides appear to be common constituents. The occurrence of the different natural phenolic acid compounds in foods is reviewed, and data of the content in fruit, vegetables, and spices are given. The distribution of the main phenolic acid compounds in food plants as well as their changes during development and maturation of fruits are considered. Furthermore, the hydroxycinnamic acids bound to cell wall polymers, the phenolic acid compounds in coffee, cereals, oil seed, and tree nuts, and the analysis of phenolic acid derivatives are reviewed.

Cinnamates↗
PubMed1951

Inhibition of Escherichia coli by p-aminobenzoic acid and its reversal by p-hydroxybenzoic acid.

p-Aminobenzoic acid (PABA) exerts three metabolic effects on E. coli: it acts as a normal vitamin at low concentrations, as a source of another vitamin, p-hydroxybenzoic acid (POB), at moderate concentrations, and as a growth inhibitor at high concentrations (150 to 1600 microg./ml.). The inhibition is competitively reversed by POB in 1/100 the concentration of PABA. The inhibition is also reversed to a limited extent by shikimic acid and compound X, precursors of POB. p-Nitrobenzoic acid is an inhibitory competitor of both POB and PABA. The retardation of growth produced by PABA and other competitive analogues of POB (p-nitrobenzoic acid; 4,4'-dihydroxydiphenyl sulfone; phenosulfazole) is converted to complete bacteriostasis by the addition of L-aspartic acid in a remarkably low concentration (1 microg./ml.)) without change in the competitive ratio with POB. The mechanism underlying this synergism is not clear. In contrast to wild type, mutants that require POB not only are inhibited by much lower concentrations of the above analogues, but also show inhibition by weaker competitors of POB such as p-hydroxybenzenesulfonamide, p-chlorobenzoic acid, and p-fluorobenzoic acid.

4-Aminobenzoic Acid↗
PubMed2001

Monitoring of reactive oxygen species production after traumatic brain injury in rats with microdialysis and the 4-hydroxybenzoic acid trapping method.

The detection of reactive oxygen species (ROS) after traumatic brain injury (TBI) is based on indirect methods due to the high reactivity and short half-life of ROS in biological tissue. The commonly used salicylate trapping method has several disadvantages making it unsuitable for human use. We have evaluated 4-hydroxybenzoic acid (4-HBA) together with microdialysis (MD) in the rat as an alternative method. 4-HBA forms one stable adduct, 3,4-dihydroxybenzoic acid (3,4-DHBA), when reacting with ROS and has not previously been used together with MD after TBI. Twenty-seven rats were used for the assessment of 3,4-DHBA production as an indicator of ROS formation in a controlled contusion injury model using intracerebral MD with 3 mM 4-HBA in the perfusate. For comparison, salicylate trapping was used in eight rats. TBI caused a 250% increase of 3,4-DHBA that peaked at 30 min after injury in severely injured rats and remained significantly elevated as compared to baseline for 90 min after trauma. The mild injury level caused a 100% increase in 3,4-DHBA formation at 30 min after the injury. When the MD probe was placed in the perimeter of the injury site, no significant increase in ROS formation occurred. Salicylate trapping showed a similar increase in adduct formation after severe injury. In addition, high cortical concentrations of 4-HBA and salicylate were found. It is concluded that microdialysis with 4-HBA as a trapping agent appears to be a useful method for ROS detection in the rat with a potential clinical utility.

Animals↗
PubMed1981

Determination and temperature effects of lidocaine (lignocaine) hydrochloride, epinephrine, methylparaben, 2,6-dimethylaniline, and p-hydroxybenzoic acid in USP lidocaine injection by ion-pair reversed-phase high pressure liquid chromatography.

USP Lidocaine injection was assayed using ion-pair high pressure liquid chromatography with an octylsilane (RP-8) reversed-phase column packing and a mobile phase consisting of D-10-camphorsulfonic acid/methanol/acetic acid/water. The effect of temperature was investigated to determine the optimum temperature for separating the drug components and their degradation products. Lidocaine (lignocaine) hydrochloride, epinephrine, methylparaben, and p-hydroxybenzoic acid were separated at 50 degrees C. 2,6-Dimethylaniline was separated from lidocaine at 15 degrees C. An aliquot of the sample was injected directly into the liquid chromatograph, and after separation the compounds were quantitated by their spectrophotometric response at 254 nm (lidocaine) or 280 nm (lidocaine plus epinephrine).

Aniline Compounds↗
PubMed1995

Structure and mechanism of para-hydroxybenzoate hydroxylase.

Para-hydroxybenzoate hydroxylase (EC 1.14.13.2) is a flavoprotein involved in degradation of aromatic compounds, and it has become a model for enzymes involved in the oxygenation of a substrate. The chemical and kinetic mechanisms of this enzyme are described and integrated with an outline of the structure of the protein from crystallographic analysis. The structure is unusual because there is no recognizable domain for the binding of NADPH involved in the reaction. Recently, mechanistic studies of site-directed mutants, combined with structural analyses, have provided some exciting discoveries about protein function. The substrate during catalysis is largely isolated from solvent in the active site, a necessary condition for successful product formation. The flavin ring structure moves substantially in the active site, probably to enable substrate and product exchange into this site and possibly to regulate the reduction of the flavin by NADPH. A chain of H-bonds can connect p-hydroxy-benzoate in the active site of the enzyme with the protein surface. This chain is responsible for the reversible formation of substrate phenolate anion observed in the active site and partly responsible for the reactivity of this substrate.

4-Hydroxybenzoate-3-Monooxygenase↗
PubMed1994

Clostridium hydroxybenzoicum sp. nov., an amino acid-utilizing, hydroxybenzoate-decarboxylating bacterium isolated from methanogenic freshwater pond sediment.

Clostridium hydroxybenzoicum JW/Z-1T (= ATCC 51151 = DSM 7310)) (T = type strain), isolated from freshwater pond sediment, is a nonmotile, gram type-positive, spore-forming, amino acid-utilizing, anaerobic rod. This bacterium produces two inducible enzymes that catalyze the decarboxylation of para-hydroxybenzoates. The phenols produced are not utilized. C. hydroxybenzoicum requires yeast extract for growth. Sugars are not utilized. Sodium ions and acetic acid stimulate growth. The optimal temperature and optimal pH for growth are 33 to 34 degrees C and 7.2 to 8.2, respectively. The DNA base composition of the type strain is 35.5 mol% guanine plus cytosine, whereas the DNA base compositions of the type strains of Clostridium sticklandii and Clostridium aminovalericum are 33 and 33.5 mol% guanine plus cytosine, respectively, as determined by a chemical method. 16S rRNA sequence analysis groups strain JW/Z-1T most closely with Clostridium purinolyticum and Clostridium acidurici (10.6 and 11 inferred changes per 100 bases, respectively). However, C. hydroxybenzoicum does not utilize uric acid, hypoxanthine, xanthine, adenine, or guanine. The cell wall type is A1 alpha (L-Lys direct).

Amino Acids↗
PubMed1985

The effect of sorbic acid and esters of p-hydroxybenzoic acid on the protonmotive force in Escherichia coli membrane vesicles.

The effect of three food preservatives, sorbic acid and methyl and butyl esters of p-hydroxybenzoic acid, on the protonmotive force in Escherichia coli membrane vesicles was investigated. Radioactive chemical probes were used to determine the two components of the protonmotive force: delta pH (pH difference) and delta psi (membrane potential). Both types of compound selectively eliminated delta pH across the membrane, while leaving delta psi much less disturbed indicating that transport inhibition by neutralization of the protonmotive force cannot be the only mechanism of action for the food preservatives tested.

Biological Transport↗
PubMed2003

Bacillus krulwichiae sp. nov., a halotolerant obligate alkaliphile that utilizes benzoate and m-hydroxybenzoate.

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 % NaCl, but not in higher concentrations. The major isoprenoid quinones were menaquinone-5, -6 and -7, and the cellular fatty acid profile consisted of significant amounts of 15-C branched-chain acids, isoC(15 : 0) and anteisoC(15 : 0). Phylogenetic analysis based on 16S rRNA gene sequencing indicated that strain AM31D(T) was a member of group 6 (alkaliphiles) in the genus Bacillus. DNA-DNA hybridization revealed a low relatedness of the isolates with several phylogenetically close neighbours, including Bacillus alcalophilus and Bacillus pseudalcaliphilus (less than 19.3 %). Based on phenotypic characteristics, phylogenetic data and DNA-DNA relatedness data, it was concluded that these isolates merited classification as a new species, for which the name Bacillus krulwichiae is proposed. The type strain of this species is AM31D(T) (=NCIMB 13904(T)=JCM 11691(T)=IAM 15000(T)).

Bacillus↗
PubMed2003

Structural signatures of the complex formed between 3-nitro-4-hydroxybenzoate and the Zn(II)-substituted R(6) insulin hexamer.

3-Nitro-4-hydroxybenzoate (3N4H) is a probe of the structure and dynamics of the metal-centered His B10 assembly sites of the insulin hexamer. Each His B10 site consists of a approximately 12 A-long cavity situated on the threefold symmetry axis. These sites play an important role in the storage and release of insulin in vivo. The allosteric behavior of the insulin hexamer is modulated by ligand binding to the His B10 zinc sites and to the phenolic pockets. Binding to these sites drives transitions among three allosteric states, designated T(6), T(3)R(3), and R(6). Although a wide variety of mono anions bind to the His B10 zinc sites of R(3), X-ray structures of ligands complexed to this site exist only for H(2)O, Cl(-), and SCN(-). This work combines one- and two-dimensional (1)H NMR and UV-Vis absorbance studies of the structure and dynamics of the 3N4H complex, which establish the following: (1). relative to the NMR time scale, 3N4H exchange between free and bound states is slow, while flipping among three equivalent orientations about the site threefold axis is fast; (2). binding of 3N4H perturbs resonances within the His B10 zinc site and generates NOEs between ligand resonances and the insulin C-alpha and side chain resonances of ValB2, AsnB3, LeuB6, and CysB7; and (3).3N4H exchange for other ligands is limited by a protein conformational transition. These results are consistent with coordination of the 3N4H carboxylate to the His B10 zinc ion and van der Waals interactions with Val B2, Asn B3, Leu B6, and Cys A7.

Allosteric Site↗
PubMed1979

A study of p-hydroxybenzoate hydroxylase from Pseudomonas fluorescens. Improved purification, relative molecular mass, and amino acid composition.

The purification procedure for p-hydroxybenzoate hydroxylase has been modified by replacement of the DEAE-cellulose (DE-32) column in the original procedure by a Sephadex--Cibacron-blue affinity column. In this way the yield of enzyme could be improved from 16% to about 40--50%. Preparative gel chromatography indicated that the enzyme does not exist as a monomeric species as earlier believed but mainly as a dimer. Sodium dodecyl sulfate gel electrophoresis of purified enzyme revealed a minimum relative molecular mass (Mr) of 43000--45000. Analytical gel chromatography, sedimentation equilibrium and sedimentation velocity experiments showed that the enzyme exists in solution mainly as a dimer but also in higher-order quaternary structures (presumably tetramer and hexamer). Temperature dependence of the distribution of the oligomers suggests that the association is of hydrophobic nature. The amino acid composition of the enzyme is also presented. The enzyme contains no disulfide but five sulfhydryl groups. In the native state of the enzyme only one sulfhydryl group is accessible to N-ethylmaleimide or 5,5'-dithiobis(2-nitrobenzoic acid). The iso-electric point of the enzyme was found to be 5.8.

4-Hydroxybenzoate-3-Monooxygenase↗
PubMed1980

The amino-acid sequence of the three smallest CNBr peptides from p-hydroxybenzoate hydroxylase from Pseudomonas fluorescens.

After CNBr cleavage of p-hydroxybenzoate hydroxylase from Pseudomonas fluorescens, five peptides and free homoserine were isolated (see preceding paper in this journal). The amino acid sequences of the three smallest peptides, viz. CB3, CB4 and CB5, were determined by automated Edman degradation and analysis of enzymatic subdigests. These peptides form a continuous stretch of 110 residues from the N terminus: (Formula: See Text).

4-Hydroxybenzoate-3-Monooxygenase↗
PubMed1983

p-Hydroxybenzoate hydroxylase from Pseudomonas fluorescens. 1. Completion of the elucidation of the primary structure.

As a final step in the elucidation of the primary structure of p-hydroxybenzoate hydroxylase from Pseudomonas fluorescens, the amino acid sequences of a CNBr peptide (CB1, positions 111-276), that accounts for the middle part of the sequence, and the C-terminal CNBr peptide (CB2, positions 277-394) from the enzyme were determined. Important sequence information was obtained from two subfragments that were formed by the cleavage with CNBr of the Met-Thr sequence (positions 346-347) in peptide CB2. The alignment of the two subfragments from peptide CB2 and three one-residue overlaps between peptides from one of these subfragments were confirmed by investigation of well-resolved parts of a 0.25-nm electron-density map. The sequence of residues 343-346 could not be determined with chemical methods and was assigned from the size and shape of the amino acids in the electron-density map. An important tool in the analysis of the amino acid sequence of peptide CB1 was the proteinase Lys-C from Lysobacter enzymogenes, which preferentially cleaves at lysine residues.

4-Hydroxybenzoate-3-Monooxygenase↗
PubMed1984

The importance of monopole-monopole and monopole-dipole interactions on the binding of NADPH and NADPH analogues to p-hydroxybenzoate hydroxylase from Pseudomonas fluorescens. Effects of pH and ionic strength.

NADPH binding to p-hydroxybenzoate hydroxylase from Pseudomonas fluorescens is found to be strongly dependent on pH and ionic strength. In the ionic strength range of 0.02-0.15 M, optimal NADPH binding is observed at a pH value of 6.4. Extrapolation of the dissociation constants to infinite ionic strength shows that under these conditions optimal binding occurs at pH values greater than 8. Similar results were obtained for complexes between the enzyme and two NADPH analogues in the presence or absence of the substrate. The experimental data can be explained by a theoretical model in which monopole-monopole or monopole-dipole interactions between the enzyme and the ligand are dominant. Changes in the former interaction prevail at low ionic strength and low pH values while the changes in the latter prevail at high ionic strength and high pH values. The dipole moment of the enzyme in the direction of the NADPH binding site was calculated from the ionic strength and pH dependence of the complex formation. The calculated dipole moment of the enzyme is about 2000 Debye at pH 6 and decreases to about 1100 Debye at pH 8.5. The results are discussed with respect to published results, including data obtained from the enzyme from a different source.

4-Hydroxybenzoate-3-Monooxygenase↗