P-Hydroxybenzoic acid propyl ester

SYNS ASEPTOFORM P BETACIDE P BONOMOLD OP 4-HYDROXYBENZOIC ACID PROPYL ESTER p-HYDROXYBENZOIC ACID PROPYL ESTER NIPASOL p-OXYBENZOESAEUREPRO-PYLESTER (GERMAN) PARABEN PARj SEPT PASEPTOL PRESERVAL P PROPYL p-HYDROXY-BENZOATE n-PROP X p-HYDROXYBENZOATE PROPYLPARABEN (FCC) PROPYLPARASEPT PROTABEN P TEGOSEPT P... 

CAS 94-13-3 EINECS/ELINCS 202-307-7 FEMA 2951 INS216 E216 Synonyms 4-Hydroxybenzoic acid, propyl ester p-Hydroxybenzoic acid, propyl ester p-Hydroxypropyl benzoate Propyl 4-hydroxybenzoate n-Propyl p-hydroxybenzoate Propyl p-hydroxybenzoate Propyl parahydroxybenzoate Propyl parasept Classification Organic ester Definition Ester of n-propyl alcohol and p-hydroxybenzoic acid Empirical C10H12O3... 

Synonyms p-Hydroxybenzoic acid, propyl ester, sodium deriv. 4-Hydroxybenzoic acid, propyl ester, sodium salt Propyl-4-hydroxybenzoate, sodium salt Propyl-p-hydroxybenzoate, sodium salt Propylparaben sodium Propylparaben sodium salt Sodium 4-propoxycarbonylphenoxide Sodium propyl 4-hydroxybenzoate Sodium propyl p-hydroxybenzoate... 

Fig. 8.12. Growth inhibition of Aspergillus niger by benzoic acid ( ), p-hydroxybenzoic acid propyl ester (o) and sorbic acid (A)...

Synonym 4-Hydroxybenzoic acid propyl ester Source Cheng, K.-W. Tang, M. Chen, Y.-P. Fluid Phase Equil. (2002), 201(1), 79-96. 

Synonyms cas 94-13-3 aseptoformp betacidep bonomoldop 4-hydroxybenzoic acid propyl ester p-... 

HYDROXYBENZOIC ACID PROPYL ESTER NIPASOL p-OXYBENZOESAUREPROPYLESTER PARABEN PARASEPT PASEPTOL... 

Hydroxybenzoic acid, propyl ester p-Hydroxybenzolc acid, propyl ester. See Propylparaben... 

These esters of p-hydroxybenzoic acid have been used primarily to prevent growth of molds but in higher concentrations possess some weak antibacterial activity. Their effective use is limited by low aqueous solubility and by reports of stinging and burning sensations related to their use in the eye. They bind to a number of nonionic surfactants and polymers, thereby reducing their bioactivity. They are used in combination, with the methyl ester at 0.03-0.1% and the propyl ester at 0.01-0.02%. Parabens have also been shown to promote corneal absorption [140]. 

Acidic preservatives are the most widely used for oral preparations, such as the p-Hydroxybenzoic acid esters and salts of benzoic acid. These are adequately soluble in aqueous systems and possess both antifungal and antibacterial properties. Methyl and propyl p-hydroxybenzoic acid are often used together in a 10 1 ratio. Concomitant use of multiple esters makes possible a higher total preservative concentration owing to the independent solubilities of each and, according to some researchers, maximizes the antimicrobial effect. 

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). 

CAS 4247-02-3 EINECS/ELINCS 224-208-8 Synonyms 4-Hydroxybenzoic acid, 2-methyl propyl ester Isobutyl 4-hydroxybenzoate Isobutyl p-hydroxybenzoate Isobutyl parahydroxybenzoate Definition Ester of isobutyl alcohol and p-hydroxybenzoic acid Empirical C11H14O3 Properties M.w. 194.25... 

The Kolbe-Schmitt reaction of potassium phenoxide with CO2 at 200 °C gives an 80% yield of p-hydroxybenzoic acid, which is used in the form of the propyl and butyl esters as a preservative in cosmetics and pharmaceuticals. 

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. 

The most common method for the preparation of PCPP is the macromolecular substitution of the polydichlorophosphazene precursor [37] (see Section 1.1). This requires the use of protecting group chemistry, as it is well known that free acid groups lead to skeletal breakdown reactions. Propylparaben, the n-propyl ester of p-hydroxybenzoic acid has been most widely used for this, with subsequent deprotection of the propyl ester by hydrolysis under basic conditions. The requirement for complete macromolecular reactions has been addressed and structurally homogeneous, fully deprotected PCPP can be attained with the correct structure on relatively large (2 kg) scales [21, 26, 38, 39]. 

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). 

Detinhion Ester of n-propyl alcohol and p-hydroxybenzoic acid... 

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). 

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... 

This is a general term referring to the methyl, ethyl, propyl, or butyl esters (acid alcohol combination) of p hydroxyben-zoic acid (parabens)—a group of antimicrobial agents used in foods, cosmetics, and drugs. Specifically, these compounds may be called methyl, ethyl, propyl, or butyl hydroxybenzoic acid, or methyl, ethyl, propyl, or butyl paraben. 

Although the esters of />-hydroxybenzoic acid are not directly determinable by the 4-aminophenazone method (see p. 514) they can easily be converted to the acid by a preliminary hydrolysis and the general method can then be applied. Johnson and Savidge have found the following procedure to be satisfactory for the determination of methyl and propyl /)-hydroxybenzoates in a number of preparations. 

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