• Journal of Microbiology
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• v.38 no.2
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• pp.53-61
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• 2000

Hydroxybenzoic acids are the most important intermediates in the degradative pathways of various aromatic compounds. Microorganisms catabolize aromatic compounds by converting them to hydroxylated intermediates and then cleave the benzene nucleus with ring dioxygenases. Hydroxylation of the benzene nucleus of an aromatic compound is an essential step for the initiation and subsequent disintegration of the benzene ring. The incorporation of two hydroxyl groups is essential for the labilization of the benzene nucleus. Monohydroxybenzoic acids such as 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, and 4-hydrosybenzoic acid, opr pyrocattechuic acid that are susceptible for subsequent oxygenative cleavage of the benzene ring. These terminal aromatic intermediates are further degraded to cellular components through ortho-and/or meta-cleavage pathways and finally lead to the formation of constituents of the TCA cycle. Many groups of microorganisms have been isolated as degraders of hydroxybenzoic acids with diverse drgradative routes and specific enzymes involved in their metabolic pahtway. Various microorganisms carry out unusual non-oxidative decarboxylation of aromatic acids and convert them to respective phenols which have been documented. Futher, Pseudomonas and Bacillus spp. are the most ubiquitous microorganisms, being the principal components of microflora of most soil and water enviroments.

• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.20-24
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• 2007

The effects of phenolic acids on inhibition of browning by the Maillard reaction were investigated with a glucose-glutamic acid model for doenjang with citric acid as the antibrowning agent and phenolic acid as its synergist. Five phenolic acids, cinnamic, coumaric, caffeic, hydroxybenzoic, and protocatechuic acids, were used. In order to investigate the antibrowning capacity, 0.1M glucose, 0.1M glutamic acid, 50mM citric acid, and 1mM phenolic acid were dissolved in 1M phosphate buffer (pH 7.0), heated at $50^{\circ}C$ for 24hr in the presence of 0.2mM $FeCl_{2}$, and stored at $4^{\circ}C$ or $30^{\circ}C$ for four weeks. Phenolic acid addition more efficiently inhibited browning during storage at $30^{\circ}C$ than at $4^{\circ}C$, without changes in pH. Hydroxybenzoic acid was the most efficient and increased the antibrowning capacity by 13% compared to sample without phenolic acids. Although caffeic and protocatechuic acids inhibited most the formation of 3-deoxyglucosone or fluorescence, they increased browning by forming colored complexes between two hydroxy groups of phenolic acids and iron ions. Hydroxybenzoic acid will be able to be a useful synergist of citric acid, an antibrowning agent in doenjang, since it is permitted for doenjang.

• Korean Journal of Weed Science
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• v.8 no.2
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• pp.169-175
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• 1988

This experiment was conducted to determine the presence of allelopathic substance in Portulaca oleracea L. Water and methanol extract from P. oleracea markedly inhibited the germination of lettuce, rice, raddish etc., indicating the presence of biological substances. The biochemical substances such as ferulic, p-coumaric, salicylic, vanillic, p-hydroxybenzoic acid etc., belonging to phenolic compounds were detected in a large amount, which may be responsible for exhibiting inhibitory effects. Various phenolic compounds were detected from different samples such as freshly, dried plants, seeds and callus. The highest amount of tannic and gallic acids were detected in dried samples of P. oleracea, the highest grantity of salicylic and vanillic acids in fresh samples, the largest amount of ferulic acid in seed sample, the highest amount of p-hydroxybenzoic and p-chlorobenzoic acids in callus. Linolenic acid was presented in amount of 9.203 mg/g in dried plant of P. oleracea as one of the major fatty acids and oxalic acid presented 27.941 mg/g as one of the major organic acids. These compounds seemed to be related to inhibitory effect of P. oleracea which needs further study.

• The Plant Pathology Journal
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• v.36 no.6
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• pp.608-617
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• 2020

The type III secretion system (T3SS) is a key virulence determinant in the infection process of Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). Pathogen constructs a type III apparatus to translocate effector proteins into host cells, which have various roles in pathogenesis. 4-Hydroxybenozic acid and vanillic acid were identified from root extract of Sedum middendorffianum to have inhibitory effect on promoter activity of hrpA gene encoding the structural protein of the T3SS apparatus. The phenolic acids at 2.5 mM significantly suppressed the expression of hopP1, hrpA, and hrpL in the hrp/hrc gene cluster without growth retardation of Pst DC3000. Auto-agglutination of Pst DC3000 cells, which is induced by T3SS, was impaired by the treatment of 4-hydroxybenzoic acid and vanillic acid. Additionally, 2.5 mM of each two phenolic acids attenuated disease symptoms including chlorosis surrounding bacterial specks on tomato leaves. Our results suggest that 4-hydroxybenzoic acid and vanillic acid are potential anti-virulence agents suppressing T3SS of Pst DC3000 for the control of bacterial diseases.

• Journal of Plant Biology
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• v.30 no.1
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• pp.11-20
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• 1987

Phenolic compounds, p-coumaric and p-hydroxybenzoic acids, known as inhibitors for development and growth of many pioneer species on early stage of succession were used for the test fo susceptibility in various herbs collected from abandoned agricultural fields in the vicinity of Amherst(U. S. A.). The percent inhibition was generally greater for p-coumaric acid than for p-hydroxybenzoic acid. Concentrations of 5$\times$10-5 and 5$\times$10-4M generally had no significant effects, but at 5$\times$10-3M was inhibitory to germination and growth of tested species. And the percent inhibition caused by the two phenolics was correlated (r=.843, p<.01). Also the indices of resistance for germination and elongation were significant (r=.695, p<.01) in this study. While Cirsium and Lepidium invading species of early stage of succession were sharply susceptible for toxic activity by phenolic acids.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.134.1-134
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• 2003

The purpose of this study was to investigate the release of p-hydroxybenzoic acid and other compounds from cell wall materials(CWM) and their cellulose fraction from carrot with chemical and enzymatic hydrolysis. To investigate this effect on cell wall chemistry of carrot, alcohol insoluble residue(AIR) of CWM were prepared and were extracted sequentially with water, imidazole, CDTA(-1, -2), Na$_2$CO$_3$(-1, -2), KOH(0.5, 1.0 and 4M), to leave a residue. These were analysed for their carbohydrate and phenolic acids composition. Arabinose and galactose were the main noncellulosic sugars. Phenolics esterified to cell walls in carrot were found to consist primarily of p-hydroxybenzoic acid with minor contribution from vanillin, ferulic acid and p-hydroxybenzaldehyde. p-Hydroxybenzoic acid was quite strongly bound to the cell wall. The contents of p-hydroxybenzoic acid in 0.5M KOH, Na$_2$CO$_3$-2, IM KOH, and ${\alpha}$-cellulose were 2,097, 1,360, 1,140, and 717 $\mu\textrm{g}$/g AIR from CWM, respectively. Alkali labile unknown aromatic compound(C$\sub$7/H$\sub$10/O$_2$) was found in ${\alpha}$ -cellulose hydrolyzate digested with driselase and cellulase. This compound was also found in hydrolyzate of 2 M trifluoroacetic acid at 120$^{\circ}C$ for 2 hours. Driselase treatment solubilized only 46.6 $\mu\textrm{g}$/g of the p-hydroxybenzoic acid from carrot AIR. These results indicate that p-hydroxybenzoic acid was associated with neutral polysaccharides, long chain galactose and branched arabinan from graded alcohol precipitation.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.232-239
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• 1996

Phenolic compounds are known to inhibit the nitrosation or oxidation reaction. In the present work, the effects of phenolic compounds including phenolic acids and flavonoids on the nitrite-scavenging and electron donating ability were tested as scavenger of nitrite which is believed to participate in the formation of N-nitroso compounds and investigated as electron donator. The nitrite scavenging ability appeared in all the phenolic acids and showed the highest value at PH 1.2. Among the Phenolic compounds, phenolic acids showed higher nitrite-scavenging action than some flavonoids. Futhermore, the nitrite scavenging action of phenolic compounds was pH dependent highest at pH 1.2 and lowest at pH 6.0. The electron donating ability (EDA) by reduction of ${\alpha},{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) among hydroxybenzoic acids was in the decreasing order of gallic acid, gentisic acid, syringic acid, protocatechuic acid, salicylic acid, vanillic acid, benzoic acid and p-hydroxybenzoic acid. EDA of hydroxycinnamic acids was in the decreasing order of hydrocaffeic acid, caffeic acid, ferulic acid, p-coumaric acid and trans-cinnamic acid. EDA of flavonoids was in the decreasing order of (+)catechin, rutin, quercetin, naringin and hesperidin. Other phenolic compounds were significantly high in electron donating abilities.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1945-1947
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• 2004

• YAKHAK HOEJI
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• v.26 no.2
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• pp.129-132
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• 1982

A GC/MS method was developed to analyze phenolic acid extract from tobacco leaf. Extracted acids were converted to their methyl esters by refluxing with 3M hydrogen chloride in methanol, and the esters were reacted with his (trimethylsilyl) trifluoroacetamide plus 10% trimethylchlorosilane to silylate the phenolic groups. Derivatives of standard salicylic, p-hydroxybenzoic, vanillic, gentisic, p-coumaric, syringic, ferulic, and sinapic acids prepared by this procedure were analyzed by GC/MS on $20m{\times}0.2mm$ column of SE-54 glass capillary. GC/MS analysis of the extract from tobacco leaf revealed the presence of salicylic, p-hydtoxybenzoic, vanillic, gentisic, protocatechuic, p-coumaric, syringic, gallic, ferulic, caffeic, sinapic, and quinic acids, respectively. The quantitative analysis of these phenolic acids were achieved by using multiple ion selection technique.

• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.859-862
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• 2007