Month: December 2022

Hungerford, Natasha L. published the artcileOccurrence of environmental contaminants (pesticides, herbicides, PAHs) in Australian/Queensland Apis mellifera honey, Safety of 2-Methoxynaphthalene, the publication is Food Additives & Contaminants, Part B: Surveillance (2021), 14(3), 193-205, database is CAplus and MEDLINE.

Honey is a popular agricultural product containing mostly sugars and water, but due to its nutritious components and natural production by honeybees (Apis mellifera) from floral nectar, it is marketed as a premium health food item. As environmental monitors, honeybees can potentially transfer environmental contaminants to honey. While pesticides can have ubiquitous presence in agricultural and urban areas, polycyclic aromatic hydrocarbons (PAHs) can be more prevalent in higher d. urban/industrial environments. Australian beehives are customarily located in rural areas/forests, but it is increasingly popular to keep hives in urban areas. This study assessed the levels of environmental contaminants in honeys (n = 212) from Queensland/Australian sources including rural, peri-urban and urban areas. Honey samples were analyzed by LC-MS/MS and GC-MS/MS for 53 herbicides, 83 pesticides, 18 breakdown products (for certain pesticides/herbicides) and 33 PAHs and showed low/negligible pesticide, herbicide and PAHs contamination, consistent regardless of honey origins.

Food Additives & Contaminants, Part B: Surveillance published new progress about 93-04-9. 93-04-9 belongs to ethers-buliding-blocks, auxiliary class Naphthalene,Ether, name is 2-Methoxynaphthalene, and the molecular formula is C11H10O, Safety of 2-Methoxynaphthalene.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Collier, Willard E. published the artcileAlkaline hydrolysis of nonphenolic β-O-4 lignin model dimers. Further studies of the substituent effect on the leaving phenoxide, Recommanded Product: 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, the publication is Holzforschung (1996), 50(5), 420-424, database is CAplus.

Reaction rates and activation parameters for the alk. hydrolysis of nonphenolic β-O-4 lignin models [2-(4-substituted-phenoxy)-1-(3,4-dimethoxyphenyl)ethanol] were compared to 2-methoxylated B-ring analogs run earlier. The Hammett plot with the best fit used σ^– values to give a ρ of 1.9 ± 0.2, while the 2-methoxyl-substituted compounds had a ρ of 2.3 ± 0.3. Compounds with a methoxyl group at the ortho position of the leaving phenoxide ion hydrolyzed slightly faster than the nonmethoxylated analogs, indicating that the 2-methoxy group is a weak electron withdrawer. The strong electron-withdrawing 4-CHO and 4-CF₃ substituents gave significantly different activation parameters than the unsubstituted compound Experiments with O-labeled water suggested that the earlier proposed S_NAr mechanism for the alk. hydrolysis of strong electron-withdrawing compounds is not correct. It appears that all nonphenolic β-O-4 dimers are hydrolyzed by a neighboring group mechanism.

Holzforschung published new progress about 183303-74-4. 183303-74-4 belongs to ethers-buliding-blocks, auxiliary class Benzene,Alcohol,Ether, name is 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol, and the molecular formula is C16H18O4, Recommanded Product: 1-(3,4-Dimethoxyphenyl)-2-phenoxyethanol.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Wu, Shengde published the artcileFramework for Identifying Chemicals with Structural Features Associated with the Potential to Act as Developmental or Reproductive Toxicants, Category: ethers-buliding-blocks, the publication is Chemical Research in Toxicology (2013), 26(12), 1840-1861, database is CAplus and MEDLINE.

Developmental and reproductive toxicity (DART) end points are important hazard end points that need to be addressed in the risk assessment of chems. to determine whether or not they are the critical effects in the overall risk assessment. These hazard end points are difficult to predict using current in silico tools because of the diversity of mechanisms of action that elicit DART effects and the potential for narrow windows of vulnerability. DART end points have been projected to consume the majority of animals used for compliance with REACH; thus, addnl. nonanimal predictive tools are urgently needed. This article presents an empirically based decision tree for determining whether or not a chem. has receptor-binding properties and structural features that are consistent with chem. structures known to have toxicity for DART end points. The decision tree is based on a detailed review of 716 chems. (664 pos., 16 neg., and 36 with insufficient data) that have DART end-point data and are grouped into defined receptor binding and chem. domains. When tested against a group of chems. not included in the training set, the decision tree is shown to identify a high percentage of chems. with known DART effects. It is proposed that this decision tree could be used both as a component of a screening system to identify chems. of potential concern and as a component of weight-of-evidence decisions based on structure-activity relationships (SAR) to fill data gaps without generating addnl. test data. In addition, the chem. groupings generated could be used as a starting point for the development of hypotheses for in vitro testing to elucidate mode of action and ultimately in the development of refined SAR principles for DART that incorporate mode of action (adverse outcome pathways).

Chemical Research in Toxicology published new progress about 1589-47-5. 1589-47-5 belongs to ethers-buliding-blocks, auxiliary class Aliphatic hydrocarbon chain,Alcohol,Ether, name is 2-Methoxypropan-1-ol, and the molecular formula is C13H9FO, Category: ethers-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Anthis, Jeffrey W. published the artcileA New Route to Chelating Bis(aryloxide) Ligands and Their Applications to Tantalum and Titanium Organometallic Compounds, Product Details of C10H14O, the publication is Inorganic Chemistry (2004), 43(2), 716-724, database is CAplus and MEDLINE.

A new route to sterically tuned, chelating bis(aryloxide) ligands is described and demonstrated by the synthesis of 2,2′-ethylenebis(6-isopropylphenol) (1, H₂BIPP) and transition metal complexes of its dianion. The utility of these ligands in titanium and tantalum organometallic chem. is shown in the alkylation of (BIPP)TiCl₂ (7) to form (BIPP)TiMe₂ (8) and (BIPP)Ti(CH₂Ph)₂ (9) and in the alkylation of (BIPP)TaCl₃ (10) and its base adducts to form (BIPP)TaMe₃ (14) and (BIPP)Ta(CH₂Ph)₃ (13). Structural comparisons of the chelating 2,2′-ethylenebis(6-isopropylphenoxide) (BIPP) ligand with its analogous, nonchelating bis(2,6-dialkylaryloxide) ligand set are examined in the x-ray diffraction studies of (BIPP)TaCl₃(THF)·THF and (BIPP)Ta(CH₂C₆H₅)₃.

Inorganic Chemistry published new progress about 2944-47-0. 2944-47-0 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether, name is 2-Isopropylanisole, and the molecular formula is C10H14O, Product Details of C10H14O.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Vicente, Estela D. published the artcileCytotoxicity and mutagenicity of particulate matter from the open burning of pruning wastes, Safety of 4-Hydroxy-3,5-dimethoxybenzaldehyde, the publication is Air Quality, Atmosphere & Health (2022), 15(2), 299-310, database is CAplus.

Burning vegetative debris is a worldwide long-standing practice. The current study was designed to examine the cytotoxicity and mutagenicity of particulate matter with an aerodynamic diameter below 10 μm (PM10) released from the burning of pruning residues common in Portugal and other countries of the Mediterranean region. Field measurements were conducted to collect PM10 samples from open burning of vines, olive, willow and acacia pruning branches. To assess the cytotoxicity of the PM10 total organic extract, the A549 cell line, representative of the alveolar type II pneumocytes of the human lung, was used. The cytotoxicity was checked using two complementary methods: water-soluble tetrazolium (WST-8) test to evaluate the cell metabolic activity and lactate dehydrogenase (LDH) activity assay to assess the loss of cell membrane integrity. The mutagenicity of the PM10-bound polycyclic aromatic hydrocarbons (PAHs) was screened through the Ames test. PM10 organic extracts induced LDH release in a dose-dependent manner. Regarding the cellular metabolic activity, dose-dependency was lacking for the majority of the samples. Combined WST-8 and LDH data indicate that PM10 exposure induce a necrotic cell death pathway in which the cell membrane integrity is lost. Direct and indirect mutagenicity towards the TA98 Salmonella strain has been recorded for the PAH extracts of PM10 collected from combustion of vine and willow branches during the ignition/flaming combustion stage. Significant correlations were found between the cytotoxic responses (WST-8 and LDH) and the PM10 organic component.

Air Quality, Atmosphere & Health published new progress about 134-96-3. 134-96-3 belongs to ethers-buliding-blocks, auxiliary class Immunology/Inflammation,COX,Natural product, name is 4-Hydroxy-3,5-dimethoxybenzaldehyde, and the molecular formula is C12H25Br, Safety of 4-Hydroxy-3,5-dimethoxybenzaldehyde.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Furst, Hans published the artcileAlkylamino pyridines and alkyl pyridine ethers. (Relations between chemical constitution and odor.), Category: ethers-buliding-blocks, the publication is Chemische Technik (Leipzig, Germany) (1958), 693-9, database is CAplus.

The synthesis of alkylandnopyridines and alkyl pyridine ethers was reported. In all cases below are given in parentheses, n²⁰_D, b.p./mm., and odor, if any, resp. 2-(Substituted amino)-pyridines were prepared by the method of Sharp (C.A. 34, 1663⁸) in 30-70% yield (substituents given: iso-Bu (1.5328, 69°/2, mignonette); n-hexyl (-,111°/2, strong mignonette); phenylethyl (-, 158°/3, weak mignonette); Et, Bu (1.5251, 125°/2, strong salicylic, ester); ethyl, n-decyl (1.5085, 132°/2, weak); ethyl, benzyl (1.5947, 112°/2, weak mignonette). 2-Methyl-6-(substituted amino)pyridine derivatives were prepared from 2-methyl-6-aminopyridine by the Tschitschibabin procedure in 80% yields: Bu (1.5329, 82°/2, earthy); iso-Am (1.5170, 91°/2, penetrating); n-hexyl (1.5205, 108°/2, weak mignonette); Et, Bu (1.5195, 85°/1, earthy); n-Pr, Bu (1.5153, 90°/1, weak mignonette); n-hexyl, Bu (1.5063, 112°/1, weak earthy). Also prepared were 2,6-Pr(PrBuN)C₅H₃N (1.5142, 90°/1, burnt), and 2,6-Bu(PrBuN)C₅H₃N (1.5138, 104°/1, burnt). 3-Methyl-6-(substituted amino)pyridine derivatives, in about 80% yields, were prepared according to the method of Stuart: Bu (1.5351, 74°/2, mignonette); n-hexyl (1.5250, 98/2, woody); benzyl (-, 122°/2, earthy, m. 76°); Et, Bu (1.5129, 72°/1, weak mignonette). 4-Methyl-6-(substituted amino)pyridine derivatives were prepared from 4-methyl-6-aminopyridine: Bu(-, 82°/2, flowery, m. 41°); iso-Bu (1.5348, 75°7/2, rooty); benzyl (-, -, weak mignonette, m. 76°); Et, Bu (1.5197, 82°/1, weak mignonette). 2-Pyridyl alkyl ethers were prepared from 2-bromopyridine and the alcs. in 60% yields (alkyl given): n-hexyl (1.4878, 73°/2, fruity); n-heptyl (1.4850, 83°/2, pleasant); isoöctyl (1.4825, 85°/2, fruity); cyclohexyl (1.5242, 65°/2, -). 2-Alkyl-6-pyridyl alkyl ethers were prepared from the corresponding ethers, NaNH₂, and the alkyl halides in 70% yields: 2-(n-butyl)-6-pyridyl, n-hexyl (1.5186, 72°/0.5, burnt); 2-(n-amyl)-6-pyridyl, n-heptyl (1.5123, 85°/0.5, celery); 2-isohexyl-6-pyridyl, n-amyl (1.4900, 98°/0.5, weak elder); 2-(n-nonyl)-6-pyridyl, n-amyl (1.4859, 130°/0.5, weak elder). 2-Methyl-6-(R-substituted)pyridine derivatives (R = alkyl or aryl) were prepared from 2,6-dimethylpyridine and R halide plus NaNH₂: Am (1.4869, 69°/2, rooty); n-hexyl (1.4867, 79°/2, rooty); n-heptyl (1.4854, 89/2, pea-like); cyclohexyl (1.5185, 75°/2, fatty); benzyl (1.5644, 94°/2, fruity). 2-Methyl-6-alkyl-pyridines were also prepared as above: isohexyl (1.4858, 52°/2, rooty), n-heptyl (1.4820, 65°/2, pealike); n-nonyl (1.4826, 85°/2, fatty); and phenylethyl (1.5679, 91°/2, fruity and leafy).

Chemische Technik (Leipzig, Germany) published new progress about 52818-63-0. 52818-63-0 belongs to ethers-buliding-blocks, auxiliary class Pyridine,Amine,Benzene,Ether, name is N-(4-Methoxybenzyl)pyridin-2-amine, and the molecular formula is C13H14N2O, Category: ethers-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Neef, C. J. published the artcileMEH-PPV: improved synthetic procedure and molecular weight control. [Erratum to document cited in CA132:308756], HPLC of Formula: 146370-51-6, the publication is Macromolecules (2004), 37(7), 2671, database is CAplus.

In Table 2 on page 2313, the polydispersity (PD) values for the polymerizations using 1.05 and 2.0% 4-methoxyphenol are listed as 1.52 and 1.14, resp. The correct PD values are 1.14 for 1.0% 4-methoxyphenol and 1.52 for 2.0% 4-methoxyphenol. The corrected table is given. The corrected values show a clear relation between the amount of 4-methoxyphenol and polymerization yield, mol. weights, and PD values.

Macromolecules published new progress about 146370-51-6. 146370-51-6 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether, name is 1-((2-Ethylhexyl)oxy)-4-methoxybenzene, and the molecular formula is C15H24O2, HPLC of Formula: 146370-51-6.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Neef, C. J. published the artcileMEH-PPV: Improved Synthetic Procedure and Molecular Weight Control, Quality Control of 146370-51-6, the publication is Macromolecules (2000), 33(7), 2311-2314, database is CAplus.

Mechanistic studies on the polymerization of α,α’-dibromo-2-methoxy-5-(2-ethylhexyloxy)xylene have been performed. Polymerizations were initially carried out by adding potassium tert-butoxide to monomer in the presence of a chain transfer agent, anthracene. Anthracene showed little effect on the mol. weight of the resulting polymer, suggesting that the major polymerization route was not radically initiated. Polymerizations were also carried out by adding monomer to potassium tert-butoxide in presence of a nucleophile, 4-methoxyphenol. The mol. weight of the resulting polymer scaled linearly with the amount of 4-methoxyphenol, suggesting an anionic mechanism. In addition, each polymerization was monitored by in-situ torque measurements to further elucidate the polymerization mechanism and optimize polymerization conditions.

Macromolecules published new progress about 146370-51-6. 146370-51-6 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether, name is 1-((2-Ethylhexyl)oxy)-4-methoxybenzene, and the molecular formula is C15H24O2, Quality Control of 146370-51-6.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Ryan, Rachael Y. M. published the artcileThe medicinal plant Tabebuia impetiginosa potently reduces pro-inflammatory cytokine responses in primary human lymphocytes, HPLC of Formula: 91-16-7, the publication is Scientific Reports (2021), 11(1), 5519, database is CAplus and MEDLINE.

Bark from the Handroanthus impetiginosus (Mart. ex DC.) Mattos (Bignoniaceae) tree has long been used in traditional South American healing practises to treat inflammation. However, its anti-inflammatory activity has not been closely examined Here we use chem. extraction, qual. phytochem. examination, toxicity testing and quant. examination of anti-inflammatory activity on human cells ex vivo. All extracts were found to be nontoxic. We found different extracts exhibited unique cytokine profiles with some extracts outperforming a pos. control used in the clinic. These results verify the immunomodulatory activity of Handroanthus impetiginosus (Mart. ex DC.) Mattos (Bignoniaceae) tree bark-derived compounds Collectively, combining a lack of toxicity and potency in human immune cells supports further fractionation and research.

Scientific Reports published new progress about 91-16-7. 91-16-7 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether,Inhibitor,Inhibitor,Inhibitor, name is 1,2-Dimethoxybenzene, and the molecular formula is C8H10O2, HPLC of Formula: 91-16-7.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Chen, Shuotong published the artcilePool complexity and molecular diversity shaped topsoil organic matter accumulation following decadal forest restoration in a karst terrain, Quality Control of 134-96-3, the publication is Soil Biology & Biochemistry (2022), 108553, database is CAplus.

Fast accumulation of soil organic matter (SOM) following forest restoration shifted from cropland has been widely reported, but how the pools and mol. composition change across soil aggregate fractions remains unclear. In this study, undisturbed topsoil (0-10 cm) samples were collected across a decadal chronosequence of forest stands (RL10, RL20 and RL40) restored for 10, 20 and 40 years following maize cropland (CL) abandonment in a karst terrain of Guizhou, Southwest China. SOM changes were explored using the size and d. fractionation of water-stable aggregates, 13C isotopic signalling and biomarker analyses as well as 13C solid-state NMR assays. Compared to that of CL, SOM content was increased by 24%, 79% and 181%, mass proportion of macroaggregates increased by 136%, 179% and 250%, and particulate organic matter (POM) increased by 13%, 108% and 382%, resp. at RL10, RL20 and RL40. With biomarker analyses, the relative abundances of plant-derived organics (lignin, cutin, suberin, wax and phytosterols), mostly protected in aggregates, increased, while those of microbe-derived OC, predominantly mineral bound, decreased in response to prolonged forest restoration. Calculated as per the Shannon diversity index (H’), changes in SOM pool complexity and mol. diversity were parallel to the SOM accumulation trend. The pool size ratio of POM to MAOM (mineral-associated organic matter) and the mol. abundance ratio of PL (plant-derived lipids) to ML (microbe-derived lipids) appeared to be indicative of SOM accumulation following forest restoration. With prolonged forest restoration, the topsoil OM shifted from microbial MAOM dominance to plant-derived POM dominance. Furthermore, the great topsoil OM enhancement in restored forest stands was shaped by pool complexity and mol. diversity changes with the complex interactions among plant-microbial-mineral assemblages in the karst topsoil. Both the pool complexity and mol. diversity of SOM should be considered in addressing carbon sequestration with forest restoration concerning the functioning of soil ecosystems and services under global change pressures.

Soil Biology & Biochemistry published new progress about 134-96-3. 134-96-3 belongs to ethers-buliding-blocks, auxiliary class Immunology/Inflammation,COX,Natural product, name is 4-Hydroxy-3,5-dimethoxybenzaldehyde, and the molecular formula is C9H10O4, Quality Control of 134-96-3.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem