Month: November 2022

Chavez, Flavio published the artcileSulfuric acid adsorbed on silica gel. An efficient catalyst for the tetrahydropyranylation of alcohols, Formula: C10H16O2, the publication is Synthetic Communications (1992), 22(1), 159-64, database is CAplus.

Sulfuric acid adsorbed on silica gel is an efficient catalyst for the tetrahydropyranylation of alcs. and phenols. The reaction takes 1 to 10 min to be completed and nearly quant. yields are obtained. The method is remarkably simple and inexpensive.

Synthetic Communications published new progress about 27943-46-0. 27943-46-0 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Alkynyl,Ether, name is 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran, and the molecular formula is C10H16O2, Formula: C10H16O2.

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

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

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

Krause, Martin published the artcileImproved chiral stationary phase based on cellulose triacetate supported on non-macroporous silica gel diol for the high-performance liquid chromatographic separation of racemic flavanones and diastereomeric flavanone glycosides, Name: 5,7-Dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chroman-4-one, the publication is Journal of Chromatography (1990), 502(2), 287-96, database is CAplus.

Microcrystalline cellulose triacetate (MCCTA) and depolymerized MCCTA were dissolved and coated on non-macroporous silica gel diol. The chiral stationary phases obtained were found to be superior to a com. available column based on cellulose triacetate for the enantiomeric separation of polyhydroxylated flavanones. Diastereomeric flavanone glycosides could also be resolved, together with the aglycons in a mixture As an example of the anal. of a complex matrix, the separation of naringenin enantiomers in a tomato skin extract is presented.

Journal of Chromatography published new progress about 69097-99-0. 69097-99-0 belongs to tetrahydropyran, auxiliary class Other Aliphatic Heterocyclic,Benzene,Phenol,Ether,Inhibitor, name is 5,7-Dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chroman-4-one, and the molecular formula is C16H14O6, Name: 5,7-Dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chroman-4-one.

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

Jose de Melo, Sebastiao published the artcileBenzo[a]pyrene hydroxylase-inducing flavonoids. Part I. Quantitative relations between chemical structure and biological activity, SDS of cas: 69097-99-0, the publication is Quimica Nova (1985), 8(1), 13-16, database is CAplus.

The ability of 14 flavonoids to induce benzo[a]pyrene hydroxylase in rat liver and lung tissue was examined in relation to their structural characteristics and physicochem. properties. The hydrophobicity index was a major determinant of activity in both tissues. Regression anal. suggested minor contributions from formal charge d. (liver) and mol. connectivity index (lung). Other structural parameters were not well correlated with biol. activity.

Quimica Nova published new progress about 69097-99-0. 69097-99-0 belongs to tetrahydropyran, auxiliary class Other Aliphatic Heterocyclic,Benzene,Phenol,Ether,Inhibitor, name is 5,7-Dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chroman-4-one, and the molecular formula is C16H14O6, SDS of cas: 69097-99-0.

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

Okuro, Kazumi published the artcileSynthesis of aryl- and vinylacetylene derivatives by copper-catalyzed reaction of aryl and vinyl iodides with terminal alkynes, Application of 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran, the publication is Journal of Organic Chemistry (1993), 58(17), 4716-21, database is CAplus.

The coupling reaction of aryl iodides with terminal alkynes by using a catalyst system of CuI-PPh₃ in the presence of K₂CO₃ as base gives the corresponding arylated alkynes in excellent yields. Addition of PPh₃ is essential for the reaction to proceed catalytically. Vinyl iodides also reacts smoothly with the alkynes to give enyne compounds with retention of the configurations. While DMF and DMSO can be used as solvents, DMSO is found to be effective for the reaction with aliphatic terminal alkynes. A reaction mechanism involving initial formation of copper acetylide species coordinated by PPh₃ followed by reaction of aryl and vinyl iodides is proposed.

Journal of Organic Chemistry published new progress about 27943-46-0. 27943-46-0 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Alkynyl,Ether, name is 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran, and the molecular formula is C10H16O2, Application of 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran.

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

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