P-Hydroxybenzoic acid ethyl ester

Synonyms cas 90-2-8 salicylaldehyde salicylic aldehyde 2-formylphenol salicylal p-Hydroxybenzoic Acid Ethyl Ester... 

Synonyms ethyl-4-hydroxybenzoate ethylparaben ethyl p-hydroxybenzoate 4-hydroxybenzoic acid ethyl ester Nipagin A ethyl parasept Solbrol A p-hydroxybenzoic acid ethyl ester... 

Procedure (See Chromatography, Appendix IIA.) Use a high-performance liquid chromatograph capable of separating acesulfame potassium and 4-hydroxybenzoic acid ethyl ester with a resolution of 2. Use a chromatograph equipped with a UV or diode array (227 nm) detector and a 25-cm x 4.6-mm (id) stainless steel column, or equivalent, packed with 3 to 5 p,m of reversed phase C18 silica gel, or equivalent. The elution is isocratic. Use a 40 60 (v/v) solution of acetoni-trile 0.01 MlL tetrabutyl ammonium hydrogen sulfate (TBAHS) in water as the mobile phase, with a flow rate of about 1 mL/min. 

HYDROXYBENZOIC ACID see HJIIOO m-HYDROXYBENZOIC ACID see HJIIOO o-HYDROXYBEXZOIC ACID see SAIOOO p-HYDROXYBEXZOIC ACID ETHYL ESTER see HJLOOO... 

Synonyms Ethylparaben, sodium salt 4-Hydroxybenzoic acid, ethyl ester, sodium salt Sodium 4-ethoxycarbonylphenoxide Sodium ethyl 4-hydroxybenzoate Sodium ethyl p-hyd roxy benzoate... 

Among the derivates of HBAs, further compounds have been identified. GUntert et al. (1986) identified ethyl esters of vanillic acid and p-hydroxybenzoic acid, and methyl esters of vanillic acid and protocatechuic acid. Ethyl esters of protocatechuic acid and vanillic acid, as well as the glucose ester of vanillic acid, were isolated from a German Riesling wine (Baderschneider and Winterhalter 2001). Analytically, HBA are mostly determined as trimethylsilane derivatives by using... 

E214 ethyl p-hydroxybenzoate Ethyl parasept 4-hydroxy-benzoic acid ethyl ester Solbrol A-, Tegosept E. 

Parabens [Napp]. TM for the methyl, propyl, butyl, and ethyl esters of p-hydroxybenzoic acid. Antimicrobial agents for foods and pharmaceuticals. Approved by FDA as GRAS. 

The alkyl esters (methyl, ethyl, and propyl) of p-hydroxybenzoic acid (the parabens) are widely used for their antifungal properties. The preservative effect of parabens tends to increase with increasing molecular mass. The methyl ester appears to be more effective against molds, whereas the propyl ester is more effective against yeasts (favored for oils and fats, for solubility reasons) (Gonzalez, Gallego, and Valcarcel, 1998). 

Ethyl par aben. 4-Hydroxybcn zoic acid ethyl ester ethyl p-b yd roxy benzoate Nipagin A Ethyl Parasept Sol brol A. CjH Oj mol wt 166 17. C 65.05%, H 6.07%, O 28.89%. Prepd by esterification of p-hydroxybenzoic acid Gavi (, Vincent, J. Soc. Chem. Ind- (London) 66t 175 (1947). 

Benzoic acid ethyl ester. See Ethyl benzoate Benzoic acid, 4-(((ethylphenylamino) methylene) amino)-, ethyl ester. See N-(p-Ethoxycarbony I phenyl )-N -ethy l-N -phenylformamidine Benzoic acid, hexahydro-. See Cyclohexanecarboxylic acid Benzoic acid, hexyl ester. See Hexyl benzoate Benzoic acid, 4-hydroxy- Benzoic acid, p-hydroxy-. See 4-Hydroxybenzoic acid Benzoic acid, 2-hydroxy-, butyl ester. See Butyl salicylate... 

Gentisic acid glycosides act as leaf movement factors in Mimosa species (E 2.2). Gallic acid is an inhibitor of flowering in Kalanchoe blossfeldiana (E 2.2). Benzoic acid, p-hydroxybenzoic acid as well as protocatechuic acid methyl and ethyl esters are secreted from the pygidial glands of water beetles as antiseptics and feeding deterrents (E 5.1). 

Benzoic acid derivatives Benzoic acid, p-hydroxybenzoic acid, protocatechuic acid methyl and ethyl esters, hydroquinone (D 22.2.5) Hydroquinone (D 22.2.5), H2O2 Secreted from the pygidial glands of the water beetles Dytiscus sp., feeding deterrent, antiseptic Synthesized in glands of the bombardier beetles Brachynus sp. (Fig. 338)... 

As p-hydroxybenzoic acid esters present a relatively high pKa value (approx. 8.5), their antimicrobial action is less dependent on the pH value of the type of food to be preserved. In this respect they are superior to the organic preservative acids. Unfavourably, as in the case of phenol, p-hydroxybenzoic acid esters may be linked to some extent to proteins, emulsifiers or other food components on account of their phenolic hydroxylic-group and thus be inactivated. The antimicrobial action of the p-hydroxybenzoic acid esters is proportional to the alkyl chain length. Thus the antimicrobial action of the methyl ester is some 3 to 4 times, that of the ethyl ester some 5 to 8 times, that of the propyl ester about 25 times as powerful as phenol (Thompson, 1994). However, superimposed on this effect may be the water solubility of the esters, which is inversely proportional to the alkyl chain length. Since the activity spectra of the individual p-hydroxybenzoic acid esters are different, the application of mixtures can be profitable. 

Applications. In many countries the methyl, ethyl and n-propyl esters of p-hydroxybenzoic acid, as well as their sodium salts, are permitted for preservation of some foods. The maximum permissible quantity is around 0.1%. In the USA methyl- and propyl-paraben are considered GRAS. The maximum permissible quantity is 0.1%. Their main field of use is not food preservation but the preservation of pharmaceutical and cosmetic fat emulsions. The usage of the butyl ester is not allowed in food applications. 

Food preservatives are used primarily to prevent or retard microbial growth. The most typical food preservatives are sorbic acid, benzoic acid, propionic acid, and methyl-, ethyl- and propyl-esters of p-hydroxybenzoic acid (PHB, parabens). 

Both aliphatic and aromatic isocyanates can be blocked by a variety of blocking agents. These include alcohols, phenols, oximes, lactams, j8-dicarbonyl compounds, bisulfite addition compounds, hydroxylamines and esters of p-hydroxybenzoic acid and salicylic acid. Perhaps the most widely used blocking agents at present are phenol, branched alcohols, 2-butanone oxime (methyl ethyl ketoxime) and 8-caprolactam. The use of blocked isocyanates in PU coatings has been comprehensively reviewed. ... 

The parabens , esters of p-hydroxybenzoic acid, especially the methyl, ethyl, propyl, and heptyl esters, are much used as food preservatives. Their high p/C (8.5) ensures their non-ionized character in neutral foods. 

C12 to C20, primarily Ci6 to ( is), used as surface lubricants in the manufacture of food-contact articles. The method, which uses ethyl palmitate (Eastman Chemicals No. 1575 Red Label) as an internal standard, has been validated at 200 ppm total FAME [185]. Other FAME standards (methyl palmitate, methyl stearate, methyl oleate, methyl linoleate and methyl linolenate) are available (Applied Science Laboratories) [116], Worked out examples of additive determinations are given in the Food Additives Analytical Manual [116], which also describes a great many of indirect food additives, such as BHA, BHT, TBHQ, l-chloro-2-propanol, DLTDP, fatty acid methyl esters, w-heptyl-p-hydroxybenzoate, propyl-gallate, sodium benzoate, sodium stearoyl-2-lactylate, sorbitol and phenolic antioxidants. EPA methods 606 and 8060 describe the CGC separation of phthalate esters (direct injection) (cf. Figure 4.2). 

Benzoic acid, 4-hydroxy-, ethyl ester ethyl p-hydroxybenzoate 2208, 2896 ... 

Anilinophenyl methacrylamide 3,5-Di-t-butyM-hydroxybenzoic acid, n-hexadecyl ester Diphenyl isooctyl phosphite Distearyl thiodipropionate Ditridecyl thiodipropionate Drometrizole N-(p-Ethoxycarbonylphenyl)-N -ethyl-N -phenylformamidine 2,2 -Methylenebis (4-ethyl-6-t-butylphenol) ... 

Triisooctyl phosphite antioxidant, polyesters Bis [3,3-bis (4-hydroxy-3-t-butylphenyl) butanoic acid], glycol 1,2-Bis (3,5-di-t-butyl-4-hydroxyhydrocinnamoyl) hydrazine Bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite 4,4 -Bis (a,a-dimethylbenzyl) diphenylamine t-Butyl hydroquinone 4,4 -Butylidenebis (6-t-butyl-m-cresol) p-Cresol/dicyclopentadiene butylated reaction product 2,6-Di-t-butyl-4-s-butylphenol 3,5-Di-t-butyl-4-hydroxybenzoic acid, n-hexadecyl ester Distearyl pentaerythrityl diphosphite Drometrizole Hexamethylenebis (3,5-di-t-butyl-4-hydroxycinnamate) Hydroquinone 4,4 -Methylenebis (2,6-di-t-butylphenol) 2,2 -Oxamidobis [ethyl 3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate]... 

A gas chromatographic method may be employed for analysis for both benzoic acid and sorbic acid in food, as described in AOAC method 983.16. The acids are extracted from an acidified aqueous homogenized food sample into ether. The acids are then extracted from the ether solution into aqueous alkali, and after acidification they are re-extracted into dichloromethane. Treatment of the residue with N-methyl-N-trimethylsilyltrifluoroacetamide converts the benzoic and sorbic acids into trimethylsilyl esters. These esters are then analyzed with a glass column packed with a support coated with OV-1, in a temperature programmed analysis. Phenylacetic and caproic acids are used as internal standards for benzoic and sorbic acids, respectively. An LC method has also been described for analysis of benzoic acid with simultaneous determination of sorbic acid, and methyl, ethyl, propyl, and butyl p-hydroxybenzoates. The preservatives were extracted from meat or seasonings with 70% ethanol, and analyzed by reversed-phase LC using a Cig stationary phase with a linear gradient from 10 to 70% methanol in 1.5% aqueous ammonium acetate and 1.5% aqueous acetic acid. 

Alkyl esters (methyl, ethyl, propyl and heptyl esters, previously also benzyl ester) of p-hydroxybenzoic (4-hydroxybenzoic) acid are... 

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