Tag: M.W=400-450

Liao, Chunyang published the artcileDetermination of Free and Conjugated Forms of Bisphenol A in Human Urine and Serum by Liquid Chromatography-Tandem Mass Spectrometry, Computed Properties of 267244-08-6, the publication is Environmental Science & Technology (2012), 46(9), 5003-5009, database is CAplus and MEDLINE.

Exposure of humans to bisphenol A (BPA), a widely used industrial chem., is well-known. In humans and animals, conjugation of BPA mol. with glucuronide or sulfate is considered as a mechanism for detoxification. Nevertheless, very few studies have directly measured free, conjugated (e.g., glucuronidated), and substituted (e.g., chlorinated) forms of BPA in human specimens. In this study, free, conjugated (BPA glucuronide or BPAG and BPA disulfate or BPADS), and substituted (chlorinated BPA; mono- [BPAMC], di-[BPADC], and trichloride [BPATrC]) forms of BPA were determined in human urine and serum samples, using solid-phase extraction (SPE) and liquid chromatog.-tandem mass spectrometry (LC-MS/MS) techniques. The instrumental calibration for each of the target compounds ranged from 0.01 to 100 ng/mL and showed excellent linearity (r > 0.99). The limits of quantification (LOQs) were 0.01 ng/mL for free BPA and 0.05 ng/mL for the conjugated and substituted BPA. Resp. recoveries of the six target compounds spiked into water blanks and sample matrixes (urine and serum), and passed through the entire anal. procedure, were 96 ± 14% and 105 ± 18% (mean ± SD) for urine samples and 87 ± 8% and 80 ± 13% for serum samples. The optimal recoveries of BPAG and BPADS in the anal. procedure indicted that no deconjugation occurred during the SPE procedure. The method was applied to measure six target chems. in urine and serum samples collected from volunteers in Albany, New York. BPA and its derivatives were found in urine samples at concentrations ranging from < LOQ to a few tens of ng/mL. In serum, free and conjugated BPA were detected at sub ng/mL concentrations, whereas BPA chlorides were not detected. The urine and serum samples were also analyzed by enzymic deconjugation and liquid-liquid extraction (LLE) for the determination of total BPA, and the results were compared with those measured by the SPE method. To our knowledge, this is the first report on the occurrence of BPAG and BPADS in human serum.

Environmental Science & Technology published new progress about 267244-08-6. 267244-08-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Chiral,Carboxylic acid,Benzene,Phenol,Alcohol,Ether,, name is (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, and the molecular formula is C21H24O8, Computed Properties of 267244-08-6.

Referemce:
https://en.wikipedia.org/wiki/Tetrahydropyran,
Tetrahydropyran – an overview | ScienceDirect Topics

Kim, Eun-Hye published the artcileExposure to phthalates and bisphenol A are associated with atopic dermatitis symptoms in children: a time-series analysis, Recommanded Product: (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, the publication is Environmental Health (London, United Kingdom) (2017), 24/1-24/8, database is CAplus and MEDLINE.

Background: Despite increasing evidence on the relationship between exposure to phthalates and bisphenol A with allergies and asthma, reports on atopic dermatitis (AD) with these chems. are few. We assessed the association between AD symptoms and the exposure to phthalates and bisphenol A and in children. Methods: We surveyed 18 boys with AD (age 3-7 years) in a day care center in Seoul between May 2009 and Apr. 2010. AD symptoms were recorded by using a daily symptom diary. We collected 460 series of pooled urine twice a day, in the morning and afternoon, over 230 working days and measured the concentrations of mono-2-ethyl-5-oxohexyl phthalate (5-oxo-MEHP), mono-2-ethyl-5-hydroxyhexyl phthalate (5-OH-MEHP), mono-iso-Bu phthalate (MnBP) and bisphenol A glucuronide (BPAG) in the pooled urine. Logistic regression was used for statistical anal. Results: Most phthalate metabolite levels were higher in the morning than in the afternoon (p<0.0001). There was seasonal variation in the levels of phthalates and bisphenol A metabolites. Levels of 5-OH-MEHP, MnBP, and BPAG were highest in summer (p<0.0001). Manifestation of AD symptoms was associated with an increase in urinary levels of MnBP (adjusted odds ratio, aOR = 2.85, 95% CI: 1.12-7.26 per 1μg/L of MnBP) and BPAG (aOR = 1.79, 95% CI: 0.91-3.52 per 1μg/L BPAG) on the same day. The levels of MnBP and BPAG in the previous day increased AD symptoms (aOR = 2.74, 95% CI: 1.21-6.20, for 1μg/L of MnBP and aOR = 2.01, 95% CI: 1.08-3.74 for 1μg/L BPAG). Conclusion: Our results suggest that exposure to phthalates and bisphenol A is associated with aggravation of AD symptoms in children.

Environmental Health (London, United Kingdom) published new progress about 267244-08-6. 267244-08-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Chiral,Carboxylic acid,Benzene,Phenol,Alcohol,Ether,, name is (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, and the molecular formula is C21H24O8, Recommanded Product: (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid.

Referemce:
https://en.wikipedia.org/wiki/Tetrahydropyran,
Tetrahydropyran – an overview | ScienceDirect Topics

Narukawa, Junichi published the artcileGlucuronidation of 1-naphthol and excretion into the vein in perfused rat kidney, Related Products of tetrahydropyran, the publication is Drug Metabolism and Disposition (2004), 32(7), 758-761, database is CAplus and MEDLINE.

UDP-glucuronosyltransferase is expressed in the proximal convoluted tubular cells of rat kidney. Kidney perfusion with a Krebs-Henseleit buffer containing 1-naphthol was performed to estimate the dynamics and disposition of the glucuronide conjugate formed in the epithelial cells of the renal tubules. When 1-naphthol was injected into the renal artery, and the perfusate from the renal vein was returned to a reservoir and recirculated through the kidney preparation (recirculating perfusion), most of the 1-naphthol was immediately excreted into the vein as a glucuronide conjugate and its concentration increased rapidly. In contrast, the 1-naphthol glucuronide appeared more slowly in the urine. 1-Naphthol was also injected during the initial 5 min of perfusion under single-pass perfusion conditions (single-pass perfusion) in situ, and the metabolite and parent compound in the venous perfusate and in urine were assayed. Under this condition, most of the 1-naphthol glucuronide was excreted into the renal vein, and not urine. Phenol UDP-glucuronosyltransferase was highly induced in the rat kidney by β-naphthoflavone treatment. Moreover, the amount of 1-naphthol glucuronide excreted in the renal vein was increased 2.7-fold in the perfused kidney of β-naphthoflavone-treated rats, but the amount in the urine was not significantly increased under single-pass perfusion conditions. These results indicate that the kidney can glucuronidate phenolic xenobiotics in epithelial cells of the tubules and excrete the resultant glucuronide into the renal vein.

Drug Metabolism and Disposition published new progress about 267244-08-6. 267244-08-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Chiral,Carboxylic acid,Benzene,Phenol,Alcohol,Ether,, name is (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, and the molecular formula is C21H24O8, Related Products of tetrahydropyran.

Referemce:
https://en.wikipedia.org/wiki/Tetrahydropyran,
Tetrahydropyran – an overview | ScienceDirect Topics

Hauck, Zane Z. published the artcileDetermination of bisphenol A-glucuronide in human urine using ultrahigh-pressure liquid chromatography/tandem mass spectrometry, Recommanded Product: (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, the publication is Rapid Communications in Mass Spectrometry (2016), 30(3), 400-406, database is CAplus and MEDLINE.

Rationale : Used widely as a plasticizer and as a monomer for plastics, bisphenol A (BPA) is under investigation as a possible endocrine disrupter. As an indication of systemic exposure, a fast and accurate assay was developed for the major BPA metabolite in human urine, BPA-monoglucuronide (BPA-G), using ultraHPLC/tandem mass spectrometry (UHPLC/MS/MS). Methods : Urine samples were prepared using solid-phase mixed-mode reversed-phase/anion-exchange extraction BPA-G was measured using UHPLC/MS/MS with an amide UHPLC column interfaced to a triple-quadrupole mass spectrometer equipped with neg. ion electrospray, collision-induced dissociation and selected reaction monitoring. [¹³C₁₂]-BPA-G was used as a surrogate standard Results : By measuring the glucuronide metabolite of BPA, potential interference due to BPA contamination from containers, solvents, pipet, etc., was avoided. The standard curve had a linear regression coefficient of 0.999, and the intra- and inter-assay variations were less than 10%. The assay was validated according to FDA guidelines. Conclusions : A fast, accurate, and highly selective method for the determination of BPA-G in human urine was developed and validated using UHPLC/MS/MS. This method is suitable for assessing human exposure to BPA. Copyright © 2016 John Wiley & Sons, Ltd.

Rapid Communications in Mass Spectrometry published new progress about 267244-08-6. 267244-08-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Chiral,Carboxylic acid,Benzene,Phenol,Alcohol,Ether,, name is (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, and the molecular formula is C21H24O8, Recommanded Product: (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid.

Referemce:
https://en.wikipedia.org/wiki/Tetrahydropyran,
Tetrahydropyran – an overview | ScienceDirect Topics

Guignard, Davy published the artcileCharacterization of the contribution of buccal absorption to internal exposure to bisphenol A through the diet, Recommanded Product: (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, the publication is Food and Chemical Toxicology (2016), 82-88, database is CAplus and MEDLINE.

The gavage route is often used for the toxicol. evaluation of food contaminants. This route does not take into account absorption of the toxicants through the buccal mucosa, as evidenced in dogs for bisphenol A (BPA). Our goal was to determine the functional significance of buccal BPA absorption during dietary exposure. Four ewes received BPA by nasogastric gavage (100 mg/kg) and through food pellets (10 mg/kg), 13 days apart. The time course of serum concentrations of BPA and its main metabolite BPA-G was submitted to non-compartmental anal. The dietary route led to 3-fold higher bioavailability as compared to gavage. The ratio of BPA-G to BPA concentrations varied greatly over time after the food administration, but not after gavage, suggesting a delayed metabolism of BPA after dietary exposure. The maximum entrance rate of BPA in the systemic circulation, determined by deconvolution anal., was much higher after dietary administration than after gavage and a biphasic pattern of BPA entry was observed in 3 of the 4 ewes. Our results evidenced a dual mechanism of BPA absorption (buccal and digestive) after dietary exposure and highlight the necessity to take buccal absorption into account when evaluating food contaminants.

Food and Chemical Toxicology published new progress about 267244-08-6. 267244-08-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Chiral,Carboxylic acid,Benzene,Phenol,Alcohol,Ether,, name is (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, and the molecular formula is C21H24O8, Recommanded Product: (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid.

Referemce:
https://en.wikipedia.org/wiki/Tetrahydropyran,
Tetrahydropyran – an overview | ScienceDirect Topics

Oldenburg, Julia published the artcileDifferent bisphenols induce non-monotonous changes in miRNA expression and LINE-1 methylation in two cell lines, Product Details of C21H24O8, the publication is Environmental Epigenetics (2021), 7(1), dvab011, database is CAplus and MEDLINE.

A 4,4′-Isopropylidenediphenol (bisphenol A, BPA), a chem. substance that is widely used mainly as a monomer in the production of polycarbonates, in epoxy resins, and in thermal papers, is suspected to cause epigenetic modifications with potentially toxic consequences. Due to its neg. health effects, BPA is banned in several products and is replaced by other bisphenols such as bisphenol S and bisphenol F. The present study examined the effects of BPA, bisphenol S, bisphenol F, p,p”-oxybisphenol, and the BPA metabolite BPA β-d-glucuronide on the expression of a set of microRNAs (miRNAs) as well as long interspersed nuclear element-1 methylation in human lung fibroblast and Caco-2 cells. The results demonstrated a significant modulation of the expression of different miRNAs in both cell lines including miR-24, miR-155, miR-21, and miR-146a, known for their regulatory functions of cell cycle, metabolism, and inflammation. At concentrations between 0.001 and 10μg/mL, especially the data of miR-155 and miR-24 displayed non-monotonous and often significant dose-response curves that were U- or bell-shaped for different substances. Addnl., BPA β-d-glucuronide also exerted significant changes in the miRNA expression. miRNA prediction anal. indicated effects on multiple mol. pathways with relevance for toxicity. Besides, long interspersed nuclear element-1 methylation, a marker for the global DNA methylation status, was significantly modulated by two concentrations of BPA and p,p’-oxybisphenol. This pilot study suggests that various bisphenols, including BPA β-d-glucuronide, affect epigenetic mechanisms, especially miRNAs. These results should stimulate extended toxicol. studies of multiple bisphenols and a potential use of miRNAs as markers.

Environmental Epigenetics published new progress about 267244-08-6. 267244-08-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Chiral,Carboxylic acid,Benzene,Phenol,Alcohol,Ether,, name is (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, and the molecular formula is C21H24O8, Product Details of C21H24O8.

Referemce:
https://en.wikipedia.org/wiki/Tetrahydropyran,
Tetrahydropyran – an overview | ScienceDirect Topics

Noureddin, M. Imadeddin published the artcileAbsorption and metabolism of bisphenol A, a possible endocrine disruptor, in the aquatic edible plant, water convolvulus (Ipomoea aquatica), Synthetic Route of 267244-08-6, the publication is Bioscience, Biotechnology, and Biochemistry (2004), 68(6), 1398-1402, database is CAplus and MEDLINE.

Water convolvulus, a vegetable, absorbed bisphenol A (BPA), an endocrine disruptor, from the medium. One week later, no BPA could be detected in the plant, indicating that BPA had been metabolized in the plant. BPA monoglucoside was detected as the BPA base at ∼10% in the roots, some in the stems, but none in the leaves. ²H-NMR analyses of MeOH extracts and hydrolyzates of the plant treated with BPA-d₁₆ showed the presence of metabolites (∼7% and 26%, resp., as BPA equivalent) other than the glucoside. Over 50% of BPA might be polymerized and/or tightly bound in the plant residues.

Bioscience, Biotechnology, and Biochemistry published new progress about 267244-08-6. 267244-08-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Chiral,Carboxylic acid,Benzene,Phenol,Alcohol,Ether,, name is (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, and the molecular formula is C21H24O8, Synthetic Route of 267244-08-6.

Referemce:
https://en.wikipedia.org/wiki/Tetrahydropyran,
Tetrahydropyran – an overview | ScienceDirect Topics

Reale, Elena published the artcileSimultaneous Quantification of Bisphenol A, Its Glucuronide Metabolite, and Commercial Alternatives by LC-MS/MS for In Vitro Skin Absorption Evaluation, SDS of cas: 267244-08-6, the publication is Chemical Research in Toxicology (2020), 33(9), 2390-2400, database is CAplus and MEDLINE.

Bisphenol A (BPA) is the most used color developer in thermal paper products such as cashiers’ receipts, followed by Bisphenol S (BPS), Wincon 8 (D-8), and Pergafast 201 (PF201). These chems. can migrate from the paper onto the skin and possibly be absorbed and metabolized. Until now, D-8 and PF201 have not been analyzed in biol. matrixes, nor has a method been developed to simultaneously quantify them, even though they are often found as mixtures Our aim was to develop and validate a method to quantify BPA, its glucuronide metabolite (BPA-G), BPS, D-8, and PF201 in in vitro skin absorption samples. After solid-phase extraction and reversed-phase chromatog., we quantified the substances in saline that had been in contact with human dermis for 24 h using a triple-quadrupole mass detector equipped with an electrospray ionization source. We assessed the method in three in vitro skin absorption assays using ex vivo human skin from one skin donor per test substance. The quantification ranges of our method were 0.2-200μg/L for BPA and 0.2-20μg/L for BPA-G, BPS, D-8, and PF201. Accuracies were within ±8% of nominal concentrations Intra-day and total precisions (%RSD) were <10% for all analytes, except for BPA in low-concentration quality control solutions (low QCs) (12.2% and 15.5%, resp.). Overall, the process efficiency was 100-113% for all analytes, except BPS low and high QCs (80% and 71%, resp.) and BPA low QCs (134%). The absorbed dose ranged from 0.02% to 49% depending on the test substance, and was not determinable for PF201. This is the first anal. method to quantify simultaneously BPA, BPA-G, and BPA alternatives in saline from in vitro skin absorption samples.

Chemical Research in Toxicology published new progress about 267244-08-6. 267244-08-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Chiral,Carboxylic acid,Benzene,Phenol,Alcohol,Ether,, name is (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, and the molecular formula is C21H24O8, SDS of cas: 267244-08-6.

Referemce:
https://en.wikipedia.org/wiki/Tetrahydropyran,
Tetrahydropyran – an overview | ScienceDirect Topics

Guignard, Davy published the artcileEvidence for bisphenol A-induced disruption of maternal thyroid homeostasis in the pregnant ewe at low level representative of human exposure, Name: (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, the publication is Chemosphere (2017), 458-467, database is CAplus and MEDLINE.

Many uncertainties remain regarding the potential of bisphenol A (BPA) as a thyroid disruptor in mammals and the relevance of exptl. data to humans. The relevance of the exposure schemes used in exptl. in vivo studies is also a major source of uncertainty when analyzing the risk of BPA exposure for human health. In this context, the goals of our study, conducted in an ovine model relevant to human gestation and thyroid physiologies, were to: (1) determine the equivalence of s.c. and dietary exposures and (2) determine if environmentally relevant doses of BPA can alter gestational and newborn thyroid functions. The difference between the two routes of exposure was mainly related to the overall BPA exposure and much less to the peak serum concentrations Interestingly, BPA-GLUC (the main metabolite of BPA) internal exposure via both routes was almost identical. The decrease in thyroid hormones concentration overtime was more accentuated in ewes treated with BPA, particularly with the medium dose (50μg/(kg.d); SC) for which the maximum BPA concentrations were predicted to be within the 1-10 ng/mL range i.e. very similar to the highest blood concentrations reported in humans. The balance between TT4 and rT3 varied differently between the vehicle and the medium dose group. The mechanisms underlying those modifications of maternal thyroid homeostasis remain to be determined Our study did not evidence significant modification of TSH secretion or binding to serum proteins but might suggest an effect at the level of deiodinases.

Chemosphere published new progress about 267244-08-6. 267244-08-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Chiral,Carboxylic acid,Benzene,Phenol,Alcohol,Ether,, name is (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, and the molecular formula is C21H24O8, Name: (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid.

Referemce:
https://en.wikipedia.org/wiki/Tetrahydropyran,
Tetrahydropyran – an overview | ScienceDirect Topics

Van de Voort, Catherine A. published the artcileMaternal and fetal pharmacokinetics of oral radiolabeled and authentic bisphenol A in the rhesus monkey, Application In Synthesis of 267244-08-6, the publication is PLoS One (2016), 11(12), e0165410/1-e0165410/16, database is CAplus and MEDLINE.

The present study was conducted in pregnant rhesus monkeys to determine the rapidity and extent to which BPA reaches the fetal compartment following oral ingestion, and the 24-h fate of BPA. To assess metabolism changes during the course of pregnancy, we compared BPA biotransformation during the second and third trimesters in the same animals, measuring the levels of sulfated, gluronidated, and free BPA in maternal serum, amniotic fluid, and fetal serum. All animals showed measurable unconjugated and conjugated BPA in the fetal compartment and slow clearance compared to maternal serum. There were higher levels of BPA-G in amniotic fluid at 150 days gestation compared to 100 days gestation, as well as higher levels of BPA-G than BPA-S. We also monitored 3H-BPA (and metabolites) in key tissues and excreta from a mother and fetus and from a non-pregnant female. The elimination of radioactivity was rapid, but residues were still detectable 24 h after dosing in all tissues analyzed. These data suggest that, in primates, rapid maternal processing of BPA does not alleviate the risk of exposure to the developing fetus. This study elevates concerns about levels of current BPA human exposure from potentially a large number of unknown sources and the risks posed to developing fetuses.

PLoS One published new progress about 267244-08-6. 267244-08-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Chiral,Carboxylic acid,Benzene,Phenol,Alcohol,Ether,, name is (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, and the molecular formula is C13H18BNO3, Application In Synthesis of 267244-08-6.

Referemce:
https://en.wikipedia.org/wiki/Tetrahydropyran,
Tetrahydropyran – an overview | ScienceDirect Topics