Topic
Benzoic acid
About: Benzoic acid is a research topic. Over the lifetime, 11832 publications have been published within this topic receiving 167127 citations. The topic is also known as: Retardex & E210.
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TL;DR: A series of CAPE analogues was synthesized and their antiradical/antioxidant effects analyzed to evaluate the effect of the presence of the double bond and of the conjugated system on the antioxidant effect.
Abstract: Caffeic acid phenethyl ester (CAPE) is a bioactive component isolated from propolis. A series of CAPE analogues was synthesized and their antiradical/antioxidant effects analyzed. The effect of the presence of the double bond and of the conjugated system on the antioxidant effect is evaluated with the analogues obtained from 3-(3,4-dihydroxyphenyl) propanoic acid. Those obtained from 2-(3,4-dihydroxyphenyl) acetic acid and 3,4-dihydroxybenzoic acid allow the evaluation of the effect of the presence of two carbons between the carbonyl and aromatic system.
55 citations
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TL;DR: In this article, the authors compared the inhibitory potential of cinnamic acids and aldehydes for cellulose and hemicellulose digestion in mixed cultures of rumen microorganisms in vitro.
Abstract: The benzoic and cinnamic acids found in forages were tested for their inhibitory effects on digestion of cellulose and hemicellulose by mixed cultures of rumen microorganisms in vitro. Rate and extent of cellulose digestion with the addition of cinnamic acids were determined. The benzoic acids and aldehydes were also compared for their inhibitory potential. Of the benzoic acid derivatives, only the parent compound (benzoic acid) inhibited in vitro dry matter disappearance (IVDMD) of cellulose after 48 h, whereas most of the cinnamic acids were inhibitory. None of these compounds depressed IVDMD of hemicellulose. Extent of cellulose digestion was unaffected by cinnamic acids, but rate of digestion was significantly reduced. The ranking of compounds for inhibitory potential was essentially reversed between 48 and 168 h of fermentation as compared with the ranking for 0 to 48 h of fermentation. There were also shifts in the molar proportions of volatile fatty acids produced between these times. The rapid reduction in concentration of cinnamic acids by microbial fermentation may explain these shifts. Benzoic aldehydes were more inhibitory of structural carbohydrate fermentation than were acids. No clear relationship existed between addition of hydroxyl or methoxyl groups to benzoic or cinnamic acids and their depressing effects on IVDMD. Cinnamic acids, which are more abundant in forages, were more inhibitory than the benzoic acids; but for all compounds, it appeared that hemicellulolytic bacteria were generally more tolerant of these compounds than the cellulolytic bacteria.
55 citations
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TL;DR: It is suggested that the influence of a vehicle on the overall absorption of a substance can be predicted by simply measuring the amount present in the stratum corneum at the end of a 30 min application period.
Abstract: SUMMARY
The influence of nine vehicles on in vivo percutaneous absorption of benzoic acid has been studied in the hairless rat. Although the vehicles used were simple in composition, the total amount of benzoic acid which penetrated varied by a factor of 50. A weak relationship was found between penetration of benzoic acid and its maximum solubility in the different vehicles. A linear relationship was demonstrated between the amount of benzoic acid present in the stratum corneum at the end of a 30 min application period and the total amount absorbed over 4 days. We suggest that the influence of a vehicle on the overall absorption of a substance can therefore be predicted by simply measuring the amount present in the stratum corneum at the end of a 30 min application period.
55 citations
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TL;DR: In this article, the effect of using weak and strong bases on the conversion and selectivity of PVA-stabilized gold nanoparticles supported on titania (AuPVA/TiO2) for benzyl alcohol oxidation was investigated.
Abstract: Gold nanoparticles have shown excellent catalytic properties in selective oxidation of alcohols in the presence of base; however, the influence of the nature and concentration of the base on gold catalyst activity and selectivity is not completely understood. We here present a study of the effect of using weak and strong bases on the conversion and selectivity of PVA-stabilized gold nanoparticles supported on titania (AuPVA/TiO2) for benzyl alcohol oxidation. The increase in the concentration of base had little effect on conversion when a weak base was used (K2CO3, Na2B4O7 and Na(CH3COO)), due to the buffer effect, but strongly affected selectivity. The bases with higher pKa values provided higher conversions and increased production of benzoic acid. For the strong base NaOH, benzoic acid was always the major product, although conversion decreases in excess of base. The formation of benzoic acid is avoided by using K2CO3 in non-aqueous media; benzaldehyde is the main product in cyclohexane whereas benzyl benzoate is also formed in significant amounts in solvent-free conditions. The promotion effect observed in the presence of base was discussed in terms of reaction mechanism.
55 citations
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TL;DR: Hildebrand′s equation appears most applicable to solvents whose solubility parameters are quite similar to those of the solutes; it is strictly applicable to nonpolar rather than polar systems.
55 citations