Phenylacetate esterases found in the human liver cytosol. Human plasma esterase also hydrolyze phenylacetate. Phenylacetate hydrolysis involved arylesterase in plasma, both arylesterase and carboxylesterase in liver microsomes and carboxylesterase in liver cytosol. Plasma hydrolysis is less important and overall esterase activity is lower in humans than in the rat.
Although there has been increasing interest in the use of high protein diets, little is known about dietary protein related changes in the mammalian metabolome. We investigated the influence of protein intake on selected tryptophan and phenolic compounds, derived from both endogenous and colonic microbial metabolism. Furthermore, potential inter-species metabolic differences were studied. For this purpose, 29 healthy subjects were allocated to a high (n = 14) or low protein diet (n = 15) for 2 weeks. In addition, 20 wild-type FVB mice were randomized to a high protein or control diet for 21 days. Plasma and urine samples were analyzed with liquid chromatography-mass spectrometry for measurement of tryptophan and phenolic metabolites. In human subjects, we observed significant changes in plasma level and urinary excretion of indoxyl sulfate (P 0.004 and P 0.001), and in urinary excretion of indoxyl glucuronide (P 0.01), kynurenic acid (P 0.006) and quinolinic acid (P 0.02). In mice, significant differences were noted in plasma tryptophan (P 0.03), indole-3-acetic acid (P 0.02), p-cresyl glucuronide (P 0.03), phenyl sulfate (P 0.004) and phenylacetic acid (P 0.01). Thus, dietary protein intake affects plasma levels and generation of various mammalian metabolites, suggesting an influence on both endogenous and colonic microbial metabolism. Metabolite changes are dissimilar between human subjects and mice, pointing to inter-species metabolic differences with respect to protein intake.
Burkholderia heleia PAK1-2 is a potent biocontrol agent isolated from rice rhizosphere, as it prevents bacterial rice seedling blight disease caused by Burkholderia plantarii. Here, we isolated a non-antibacterial metabolite from the culture fluid of B. heleia PAK1-2 that was able to suppress B. plantarii virulence and subsequently identified as indole-3-acetic acid (IAA). IAA suppressed the production of tropolone in B. plantarii in a dose-dependent manner without any antibacterial and quorum quenching activity, suggesting that IAA inhibited steps of tropolone biosynthesis. Consistent with this, supplementing cultures of B. plantarii with either L-[ring-(2)H5]phenylalanine or [ring-(2)H2~5]phenylacetic acid revealed that phenylacetic acid (PAA), which is the dominant metabolite during the early growth stage, is a direct precursor of tropolone. Exposure of B. plantarii to IAA suppressed production of both PAA and tropolone. These data particularly showed that IAA produced by B. heleia PAK1-2 disrupts tropolone production during bioconversion of PAA to tropolone via the ring-rearrangement on the phenyl group of the precursor to attenuate the virulence of B. plantarii. B. heleia PAK1-2 is thus likely a microbial community coordinating bacterium in rhizosphere ecosystems, which never eliminates phytopathogens but only represses production of phytotoxins or bacteriocidal substances.
2-phenylethylamine is an endogenous constituent of the human brain and is implicated in cerebral transmission. This bioactive amine is also present in certain foodstuffs such as chocolate, cheese and wine and may cause undesirable side effects in susceptible individuals. Metabolism of 2-phenylethylamine to phenylacetaldehyde is catalyzed by monoamine oxidase B but the oxidation to its acid is usually ascribed to aldehyde dehydrogenase and the contribution of aldehyde oxidase and xanthine oxidase, if any, is ignored. The objective of this study was to elucidate the role of the molybdenum hydroxylases, aldehyde oxidase and xanthine oxidase, in the metabolism of phenylacetaldehyde derived from its parent biogenic amine. Treatments of 2-phenylethylamine with monoamine oxidase were carried out for the production of phenylacetaldehyde, as well as treatments of synthetic or enzymatic-generated phenylacetaldehyde with aldehyde oxidase, xanthine oxidase and aldehyde dehydrogenase. The results indicated that phenylacetaldehyde is metabolized mainly to phenylacetic acid with lower concentrations of 2-phenylethanol by all three oxidizing enzymes. Aldehyde dehydrogenase was the predominant enzyme involved in phenylacetaldehyde oxidation and thus it has a major role in 2-phenylethylamine metabolism with aldehyde oxidase playing a less prominent role. Xanthine oxidase does not contribute to the oxidation of phenylacetaldehyde due to low amounts being present in guinea pig. Thus aldehyde dehydrogenase is not the only enzyme oxidizing xenobiotic and endobiotic aldehydes and the role of aldehyde oxidase in such reactions should not be ignored.
Phenylacetic acid, the major metabolite of phenylethylamine, has been identified and quantitated in rat brain regions by capillary column high-resolution gas chromatography mass spectrometry. Its distribution is heterogeneous and correlates with that of phenylethylamine. The values obtained were (ng/g +/- SEM): whole brain, 31.2 +/- 2.7; caudate nucleus, 64.6 +/- 6.5; hypothalamus, 60.1 +/- 7.4; cerebellum, 31.3 +/- 2.9; brainstem, 33.1 +/- 3.3, and the "rest," 27.6 +/- 3.0.
IDENTIFICATION AND USE: Phenylacetic acid forms white to yellow crystals or flakes. It is used in perfume, as a precursor in manufacture of penicillin G, fungicide, flavoring, and laboratory reagent. It is also used in production of drugs of abuse. HUMAN STUDIES: Inhalation exposure leads to cough, sore throat. Skin exposure leads to redness. Eyes exposure leads to redness, pain. ANIMAL STUDIES: Acute oral toxicity in rats is low. In study of acute effects in mice, ip injection of 300 mg/kg was toxic. Phenylacetic acid did not promote tumor formation when given to rabbits iv and sc for 40 days. In vitro phenylacetic acid induced dose-related embryotoxicity above 0.3 mg/mL. In teratogenic study with rats, administration of 3.2 mg/kg phenylacetic acid on 12th day of embryogenesis affected body weight, retarded skeletal ossification, and caused embryos to be resorbed at twice rate of controls. Phenylacetic acid inhibits activity of coenzyme A.
Uremic toxins such as phenylacetic acid are actively transported into the kidneys via organic ion transporters (especially OAT3). Increased levels of uremic toxins can stimulate the production of reactive oxygen species. This seems to be mediated by the direct binding or inhibition by uremic toxins of the enzyme NADPH oxidase (especially NOX4 which is abundant in the kidneys and heart) (A7868). Reactive oxygen species can induce several different DNA methyltransferases (DNMTs) which are involved in the silencing of a protein known as KLOTHO. KLOTHO has been identified as having important roles in anti-aging, mineral metabolism, and vitamin D metabolism. A number of studies have indicated that KLOTHO mRNA and protein levels are reduced during acute or chronic kidney diseases in response to high local levels of reactive oxygen species (A7869)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌物分类
对人类无致癌性（未列入国际癌症研究机构名录）。
No indication of carcinogenicity to humans (not listed by IARC).
来源:Toxin and Toxin Target Database (T3DB)
毒理性
健康影响
长期暴露于尿毒症毒素可能会导致多种疾病，包括肾脏损伤、慢性肾病和心血管疾病。
Chronic exposure to uremic toxins can lead to a number of conditions including renal damage, chronic kidney disease and cardiovascular disease.
... Although exhaled volatile organic compound (VOC) patterns change in obstructive sleep apnea (OSA) patients, individual VOC profiles are not fully determined. The primary outcome was VOC characterizations; secondary outcomes included their relationships with sleep and clinical parameters in OSA patients. We prospectively examined 32 OSA patients with an apnea-hypopnea index (AHI) >/= 15 by full polysomnography, and 33 age- and sex-matched controls without obvious OSA symptoms. Nine severe OSA patients were examined before and after continuous positive airway pressure (CPAP) treatment. By applying a method which eliminates environmental VOC influences, exhaled VOCs were identified by gas chromatography (GC)-mass spectrometry, and their concentrations were determined by GC. Exhaled aromatic hydrocarbon concentrations (toluene, ethylbenzene, p-xylene, and phenylacetic acid) in the severe OSA groups (AHI >/= 30) and exhaled saturated hydrocarbon concentrations (hexane, heptane, octane, nonane, and decane) in the most severe OSA group (AHI >/= 60) were higher than those in the control group. Exhaled isoprene concentrations were increased in all OSA groups (AHI >/= 15); acetone concentration was increased in the most severe OSA group. Ethylbenzene, p-xylene, phenylacetic acid, and nonane concentrations were increased according to OSA severity, and correlated with AHI, arousal index, and duration of percutaneous oxygen saturation (SpO2) </= 90%. Multiple regression analyses revealed these 4 VOC levels were associated with the duration of SpO2 </= 90%. Isoprene and acetone decreased after CPAP treatment. OSA increased some toxic VOCs, and some correlated with OSA severity. CPAP treatment possibly ameliorates these productions.
来源:Hazardous Substances Data Bank (HSDB)
吸收、分配和排泄
在 I 期临床试验中，对 17 名接受单次静脉推注和随后 14 天连续静脉输注药物的晚期实体瘤患者进行了苯乙酸（苯乙酸盐）的剂量限制毒性和药代动力学研究。苯乙酸显示出非线性药代动力学，有证据表明药物清除增加。苯乙酸的 99% 消除是通过转化为在尿液中排泄的苯乙酰谷氨酰胺来实现的...
The dose limiting toxicity and pharmacokinetics of phenylacetic acid (phenylacetate) were studied in 17 patients with advanced solid tumors who received single iv bolus doses followed by a 14 day continuous iv infusion of the drug in a phase I trial. Phenylacetic acid displayed nonlinear pharmacokinetics with evidence for induction of drug clearance. Ninety-nine percent of phenylacetic acid elimination was accounted for by conversion to phenylacetylglutamine which was excreted in the urine...
Man excreted 93%...as glutamine conjugate... . New world monkeys excreted conjugates of glutamine, glycine and taurine, while old world species excreted large proportion of free acid and only glutamine and taurine conjugates. Non-primate species excreted only glycine connjugate.
