Benzoates resistance

Makdesi, A.K. and L.R. Beughat. 1996. Improved selective medium for enumeration of benzoate-resistant, heat-stressed Zygosaccharomyces bailii. Food Microbiol. 13 281-290. 

Besides appHcation as heat-resistant molding powders for electronic and other appHcations, DAIP copolymers have been proposed for optical apphcations. Lenses of high impact resistance contain 50% DAIP, 20% benzyl methacrylate, and larger amounts of CR-39 (59). A lens of refractive index 71- = 1.569 andlow dispersion can be cast from phenyl methacrylate, DAIP, and isopropyl peroxide (60). Lenses of better impact properties can be obtained by modifying DAIP with aHyl benzoate (61). 

Plasticizers. Plasticizers are materials that soften and flexibilize inherently rigid, and even britde polymers. Organic esters are widely used as plasticizers in polymers (97,98). These esters include the benzoats, phthalates, terephthalates, and trimeUitates, and aUphatic dibasic acid esters. Eor example, triethylene glycol bis(2-ethylbutyrate) [95-08-9] is a plasticizer for poly(vinyl butyral) [63148-65-2] which is used in laminated safety glass (see Vinyl POLYMERS, poly(vinyl acetals)). Di(2-ethyUiexyl)phthalate [117-81-7] (DOP) is a preeminent plasticizer. Variation of acid and/or alcohol component(s) modifies the efficacy of the resultant ester as a plasticizer. In phthalate plasticizers, molecular sizes of the alcohol moiety can be varied from methyl to tridecyl to control permanence, compatibiUty, and efficiency branched (eg, 2-ethylhexyl, isodecyl) for rapid absorption and fusion linear (C6—Cll) for low temperature flexibiUty and low volatility and aromatic (benzyl) for solvating. Terephthalates are recognized for their migration resistance, and trimeUitates for their low volatility in plasticizer appHcations. 

Small amounts of stabiliser (1-5%) are normally added to improve weather resistance. These materials are the usual ultraviolet light absorbers such as phenyl salicylate and various benzoates. Triphenyl phosphate also has a beneficial influence. 

Of a somewhat lower level of heat resistance is poly(ethyleneoxy benzoate), which has the structure ... 

Plasticizers soften the film and increase the adhesion and the setting speed. The most common are phthalates, adipates and benzoates. The amount added can be in a broad range of 10-50%. They affect the swelling and softening of the PVAc emulsion particles, ensure film formation at room temperature, and the tack of the still wet adhesive. They also provide improved moisture resistance of the bond. Disadvantages are the lower resistance of the bond line against heat, possible migration of the plasticizers and enhanced cold flow. 

Heavy-metal cations and oxyanions are generally toxic to bacteria although resistance may be induced by various mechanisms after exposure. Attention is drawn to an unusual example in which AF+ may be significant, since the catechol 1,2-dioxygenase and 3,4-dihydroxybenzoate (protocat-echuate) 3,4-dioxygenase that are involved in the metabolism of benzoate by strains of Rhizobium trifolii are highly sensitive to inhibition by AP (Chen et al. 1985). 

In a series of ten morphine 3-benzoates, large differences in rates of enzymatic hydrolysis were seen [122], In 80% human plasma at pH 7.4 and 37°, the unsubstituted 3-benzoate had a tm value of 0.6 h, whereas esters of 2,6-disubstituted benzoic acid were much more resistant to enzymatic attack (t1/2 ranging from 60 h for the dimethylbenzoate to 300 h for the dichloro-and dimethoxybenzoates). Although these results point to marked steric hindrance, electronic effects cannot be excluded but escape characterization because of the limited series. Furthermore, and as mentioned repeatedly in this text, the possibility of binding to plasma proteins is a complicating factor that should be kept in mind. 

To date the evidence seems to favor the binding of tumor promoter to phospholipid in the cell membrane. Specific binding of [3h]TPA to mouse epidermal particulate matter is susceptible to phospholipases C and A2, less susceptible to protease, and completely resistant to glycosidase (32). Photoaffinity labelling studies with [20-3h]-phorbol 12-p-azidobenzoate 13-benzoate indicates that the irreversible binding of this photolabile phorbol ester to mouse brain membrane is predominantly to the phospholipid (specifically phosphatidylethanolamine and phosphatidylserine) portion rather than to the protein portion (33). 

Aromatic acid chlorides react with phosphine at 50 °C in absolute pyridine to form mono-, di- and triacylphosphines. For example, PH3 and benzoyl chloride give tribenzoylphosphine, a yellow crystalline compound which is resistent to water and dilute acids but is hydrolysed to PH3 and alkali benzoate by alkalis... 

Acute dystonias are typically seen in the first few days to weeks of treatment and can occur with even limited exposure (e.g., children treated with a single dose of prochlorperazine for nausea). Although dystonias may disappear spontaneously, they should be treated aggressively, as they are often painful and upsetting to the patient. Rarely, laryngeal dystonias may seriously compromise respiration. Occasionally, an acute dystonic reaction is resistant to standard treatment but may respond to parenteral diazepam, caffeine sodium benzoate, or barbiturate-induced sleep. 

The C-3 tosylate ester of I,2 5,6-di-0-isopropylidene-QL-D-glucofuranose is particularly resistant to displacement with charged nucleophiles [96]. The -elimination product is usually observed because of the trans relation between the leaving group and H-4. The C-3 imidazylate ester is displaced by several nucleophiles under mild conditions and in good yields [68] (Scheme 14). The facile displacement with benzoate ion [97] is note-... 

The solid-phase synthesis of oligosaccharides is usually performed using acid-resistant linkers and protective groups, because of the slightly acidic reaction conditions required for glycosylations (Section 16.3). Hydroxyl group protection is conveniently achieved by conversion into carboxylic esters, such as acetates, benzoates, or nitro-benzoates. Support-bound esters of primary or secondary aliphatic alcohols can be cleaved by treatment with alcoholates [97-99] (Table 7.8), with DBU in methanol, with hydrazine in DMF [100] or dioxane [101], or with ethylenediamine [102], provided that a linker resistant towards nucleophiles has been chosen. 

Brigl and Muhlschlegel148 were able to isolate 3,4,5,6-tetra-O-benzoyl-D-glucose diethyl thioacetal from the thioacetal and benzoyl chloride in an aqueous solution of alkali. When the reaction is carried out in pyridine, both the tetra- and the penta-benzoate are obtained. The tetrabenzoate has been described as a convenient intermediate for the synthesis of 2-0-methyl-n-glucose and its derivatives.149 It is somewhat surprising that position 2 should exhibit this resistance to benzoylation, since preferential methylation occurs in this position. A benzoyl migration could possibly explain the anomalous observations. 

Although the ALS inhibitor herbicides have been used for approximately 20 years, the number of resistant weed biotypes for this group now exceeds those for all other types of herbicides. Singh and Shaner (1995) and Boutsalis (2001) reported that a total of five chemical families or herbicide classes are commercially marketed as inhibitors of ALS, and that these herbicides comprise more than 50 active ingredients for selective use in many different crops. They include sulfonylureas, imidazolinones, triazolopyrimidines, sulfonylamino-carbonyl-triazolinones, and pyrimidinyl (thio)benzoates. 

Curtin et. al. W exposed benzoic acid crystals to ammonia gas and generated ammonium benzoate. As shown In Figure 7, the (101) faces of the crystals become opaque while the (001) faces remain clear. The resistance of molecules at the (001) faces to reaction with ammonia Is explainable by the relatively unexposed carboxyl groups within this region. 

---