Month: December 2022

Khachatoorian, Careen published the artcileTracing the movement of electronic cigarette flavor chemicals and nicotine from refill fluids to aerosol, lungs, exhale, and the environment, HPLC of Formula: 103-26-4, the publication is Chemosphere (2022), 286(Part_3), 131494, database is CAplus and MEDLINE.

Given the high concentrations of nicotine and flavor chems. in EC (electronic cigarette) fluids, it is important to determine how efficiently they transfer to aerosols, how well they are retained by users (exposure), and if they are exhaled into the environment where they settle of surfaces forming ECEAR (EC exhaled aerosol residue). To quantify the flavor chems. and nicotine in refill fluids, inhaled aerosols, and exhaled aerosols. Then deduce their retention and contribution to ECEAR. Flavor chems. and nicotine were identified and quantified by GC-MS in two refill fluids, smoking machine-generated aerosols, and aerosols exhaled by 10 human participants (average age 21; 7 males). Machine generated aerosols were made with varying puff durations and two wattages (40 and 80). Participants generated exhale ad libitum; their exhale was quantified, and chem. retention and contribution to ECEAR was modeled.”. Dewberry Cream” had five dominant (≥1 mg/mL) flavor chems. (maltol, ethyl maltol, vanillin, Et vanillin, furaneol), while “Cinnamon Roll” had one (cinnamaldehyde). Nicotine transferred well to aerosols irresp. of topog.; however, transfer efficiencies of flavor chems. depended on the chem., puff volume, puff duration, pump head, and EC power. Participants could be classified as “mouth inhalers” or “lung inhalers” based on their exhale of flavor chems. and nicotine and retention. Lung inhalers had high retention and exhaled low concentrations of EC chems. Only mouth inhalers exhaled sufficient concentrations of flavor chems./nicotine to contribute to chem. deposition on environmental surfaces (ECEAR). These data help distinguish two types of EC users, add to our knowledge of chem. exposure during vaping, and provide information useful in regulating EC use.

Chemosphere published new progress about 103-26-4. 103-26-4 belongs to esters-buliding-blocks, auxiliary class Alkenyl,Benzene,Ester,Protease,Tyrosinase,Natural product, name is Methyl 3-phenyl-2-propenoate, and the molecular formula is C10H10O2, HPLC of Formula: 103-26-4.

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

Chen, Yiding published the artcilePhotoredox Generation of Sulfonyl Radicals and Coupling with Electron Deficient Olefins, Quality Control of 617-52-7, the publication is Organic Letters (2020), 22(15), 5746-5748, database is CAplus and MEDLINE.

Various sulfone tetrazoles were activated via iridium photoredox catalysis in the presence of DMAP to gave dialkyl sulfones such as I [R¹ = 4-FC₆H₄CH₂CH₂, 4-ClC₆H₄CH₂, tetralin-2-yl, etc.; R² = CN, C(O)OEt, C(O)O-Bn, etc., R³ = H, CH₂C(O)OMe; R²R³ = CH₂CH₂OC(O); R⁴ = H, Me]. The presumed sulfone radical intermediates were trapped by a range of electron-deficient olefins in generally good to excellent yields.

Organic Letters published new progress about 617-52-7. 617-52-7 belongs to esters-buliding-blocks, auxiliary class Alkenyl,Aliphatic hydrocarbon chain,Ester, name is Dimethyl itaconate, and the molecular formula is C7H10O4, Quality Control of 617-52-7.

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

Starratt, A. N. published the artcileMonitoring fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), moth populations in southwestern Ontario with sex pheromone traps, Product Details of C14H26O2, the publication is Canadian Entomologist (1982), 114(7), 545-9, database is CAplus.

Pheromone traps were more efficient than blacklight traps for detecting and monitoring adult populations of fall armyworm (S. frugiperda) in southwestern Ontario. Several dispenser-chem. combinations were strongly attractive but best results were obtained with sticky traps baited with rubber septa impregnated with combinations of (Z)-9-dodecenyl acetate  [16974-11-1] and (Z)-9-tetradecenyl acetate  [16725-53-4].

Canadian Entomologist published new progress about 16974-11-1. 16974-11-1 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is (Z)-Dodec-9-en-1-yl acetate, and the molecular formula is C19H21N3O3S, Product Details of C14H26O2.

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

Boyle, Sean Michael published the artcileExpanding the olfactory code by in silico decoding of odor-receptor chemical space, Recommanded Product: Ethyl 2-mercaptopropanoate, the publication is eLife (2013), e01120/1-e01120/17, 17 pp., database is CAplus and MEDLINE.

Coding of information in the peripheral olfactory system depends on two fundamental factors: interaction of individual odors with subsets of the odorant receptor repertoire and mode of signaling that an individual receptor-odor interaction elicits, activation or inhibition. We develop a cheminformatics pipeline that predicts receptor-odorant interactions from a large collection of chem. structures (>240,000) for receptors that have been tested to a smaller panel of odorants (∼100). Using a computational approach, we first identify shared structural features from known ligands of individual receptors. We then use these features to screen in silico new candidate ligands from >240,000 potential volatiles for several Odorant receptors (Ors) in the Drosophila antenna. Functional experiments from 9 Ors support a high success rate (∼71%) for the screen, resulting in identification of numerous new activators and inhibitors. Such computational prediction of receptor-odor interactions has the potential to enable systems level anal. of olfactory receptor repertoires in organisms.

eLife published new progress about 19788-49-9. 19788-49-9 belongs to esters-buliding-blocks, auxiliary class Thiol,Aliphatic hydrocarbon chain,Ester, name is Ethyl 2-mercaptopropanoate, and the molecular formula is C5H10O2S, Recommanded Product: Ethyl 2-mercaptopropanoate.

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

Roberts, David C. published the artcileAcetoacetic ester condensation. XI. The extent of the condensation of certain monosubstituted acetic esters, HPLC of Formula: 5340-78-3, the publication is Journal of the American Chemical Society (1937), 2007-8, database is CAplus.

cf. C. A. 29, 6212.5. With 0.4 mol. EtONa and 2.4 mols. of ester, the following yields of RCH₂COCHRCO₂Et were obtained (at 95° except for R = H (78°)): R = H, 75-6% (based on EtONa); Me, 46-7; Et, 40-2; Pr, 34-35; Me₂CH and Me₃C, 0; Ph 53-5. Thus, the substitution of a normal alkyl group for one of the Me-H atoms of AcOEt progressively lowered the extent of the condensation as the size of the alkyl group increased. Sec. and tert substituents completely prevented the condensation, even under conditions that would allow the reaction to proceed to completion. PhCH₂CO₂Et condensed to a less extent than did AcOEt but to a considerably greater extent than did any of alkyl-substituted esters.

Journal of the American Chemical Society published new progress about 5340-78-3. 5340-78-3 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is Ethyltert-butylacetate, and the molecular formula is C8H16O2, HPLC of Formula: 5340-78-3.

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

Marques, Francisco De A. published the artcileKovats retention indexes of monounsaturated C₁₂, C₁₄, and C₁₆ alcohols, acetates and aldehydes commonly found in lepidopteran pheromone blends, Related Products of esters-buliding-blocks, the publication is Journal of the Brazilian Chemical Society (2000), 11(6), 592-599, database is CAplus.

Many lepidopteran pheromones consist of blends of monounsaturated alcs., aldehydes and acetates. These compounds frequently are obtained in only nanogram quantities from pheromone gland extracts, prohibiting use of most standard spectroscopic methods. However, use of GC retention indexes, particularly in combination with mass spectrometry and electroantennograms, can provide substantial information about trace amounts of unknowns. Comparison of Kovats indexes (KIs) of an unknown with those of standards can provide an unambiguous identification, or at least, limit the number of possible structures to a few compounds Furthermore, because KIs are highly reproducible, a full set of standards is not necessary; comparisons can be made using tables of KIs determined in another laboratory We provide here tables of the KIs of almost all possible isomers of monounsaturated alcs., aldehydes, and acetates with 12, 14, or 16 carbon chain lengths, measured on nonpolar (DB-5) and polar (DB-WAX) stationary phases.

Journal of the Brazilian Chemical Society published new progress about 16974-11-1. 16974-11-1 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is (Z)-Dodec-9-en-1-yl acetate, and the molecular formula is C14H26O2, Related Products of esters-buliding-blocks.

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

Smith, M. T. published the artcileHickory shuckworm Cydia caryana: electroantennogram and flight tunnel studies of potential sex pheromone components, Product Details of C14H26O2, the publication is Entomologia Experimentalis et Applicata (1987), 44(1), 23-30, database is CAplus.

Electroantennogram (EAG) measurements of male C. caryana moth antennal olfactory response to monounsaturated 12 and 14 carbon alcs. and acetates indicated that the (E)-8-, (E)-10-conjugated double bond system of a dodecadien-1-ol acetate is a critical chem. structural component of the C. caryana sex pheromone. Addnl., EAG measurements implicated (E)-8-dodecen-1-ol acetate, (Z)-8-dodecen-1-ol acetate, (Z)-9-dodecen-1-ol acetate, and (Z)-12-tetradecen-1-ol as potential minor pheromonal components. An EAG dosage-response study suggested that there were ≥2 heterologous populations of pheromone acceptors. Behavioral anal. of male moth response in a flight tunnel to compounds which evoked the stronger EAG responses suggested that (E,E)-8,10-dodecadien-1-ol acetate and (Z)-9-dodecen-1-ol acetate resemble or are C. caryana sex pheromonal components, while (Z)-8-dodecen-1-ol acetate and (E)-10-dodecen-1-ol acetate are either parapheromones or are minor pheromone components. Behavioral significance of (Z)-12-tetradecen-1-ol was difficult to interpret in the flight tunnel.

Entomologia Experimentalis et Applicata published new progress about 16974-11-1. 16974-11-1 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is (Z)-Dodec-9-en-1-yl acetate, and the molecular formula is C16H24BF4Ir, Product Details of C14H26O2.

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

Pirkle, William H. published the artcileAn improved chiral stationary phase for the facile separation of enantiomers, Category: esters-buliding-blocks, the publication is Journal of Chromatography (1988), 441(2), 311-22, database is CAplus.

A chiral stationary phase (CSP) derived from cis-3-(1,1-dimethylethyl)-4-phenyl-2-azetidinone is quite effective for the chromatog. separation of the enantiomers of a variety of compounds This CSP has two stereogenic centers. For many enantiomers, it exhibits superior performance to that of a widely used phenylglycine-derived CSP.

Journal of Chromatography published new progress about 5340-78-3. 5340-78-3 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is Ethyltert-butylacetate, and the molecular formula is C8H16O2, Category: esters-buliding-blocks.

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

Ward, Lucy C. published the artcileCarboxyl Methyltransferase Catalysed Formation of Mono- and Dimethyl Esters under Aqueous Conditions: Application in Cascade Biocatalysis, Recommanded Product: 3-(Methoxycarbonyl)benzoic acid, the publication is Angewandte Chemie, International Edition (2022), 61(14), e202117324, database is CAplus and MEDLINE.

Carboxyl methyltransferase (CMT) enzymes catalyze the biomethylation of carboxylic acids under aqueous conditions and have potential for use in synthetic enzyme cascades. Herein we report that the enzyme FtpM from Aspergillus fumigatus can methylate a broad range of aromatic mono- and dicarboxylic acids in good to excellent conversions. The enzyme shows high regioselectivity on its natural substrate fumaryl-L-tyrosine, trans, trans-muconic acid and a number of the dicarboxylic acids tested. Dicarboxylic acids are generally better substrates than monocarboxylic acids, although some substituents are able to compensate for the absence of a second acid group. For dicarboxylic acids, the second methylation shows strong pH dependency with an optimum at pH 5.5-6. Potential for application in industrial biotechnol. was demonstrated in a cascade for the production of a bioplastics precursor (FDME) from bioderived 5-hydroxymethylfurfural (HMF).

Angewandte Chemie, International Edition published new progress about 1877-71-0. 1877-71-0 belongs to esters-buliding-blocks, auxiliary class Carboxylic acid,Benzene,Ester, name is 3-(Methoxycarbonyl)benzoic acid, and the molecular formula is C8H5F3N4, Recommanded Product: 3-(Methoxycarbonyl)benzoic acid.

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

Abel, Brooks A. published the artcile“One-Pot” Aminolysis/Thiol-Maleimide End-Group Functionalization of RAFT Polymers: Identifying and Preventing Michael Addition Side Reactions, Product Details of C5H10O2S, the publication is Macromolecules (Washington, DC, United States) (2016), 49(17), 6193-6202, database is CAplus.

We show that many of the nucleophiles (catalysts, reducing agents, amines, thiols) present during “one-pot” aminolysis/thiol-maleimide end-group functionalization of RAFT polymers can promote side reactions that substantially reduce polymer end-group functionalization efficiencies. The nucleophilic catalyst 1,8-diazabicyclo[5.4.0]undec-7-ene and the reducing agent tributylphosphine were shown to initiate anionic polymerization of N-methylmaleimide (NMM) in both polar and nonpolar solvents whereas hexylamine-initiated polymerization of NMM occurred only in high-polarity solvents. Furthermore, triethylamine-catalyzed Michael reactions of the representative thiol Et 2-mercaptopropionate (E2MP) and NMM in polar solvents resulted in anionic maleimide polymerization when [NMM]₀ > [E2MP]₀. Base-catalyzed enolate formation on the α-carbon of thiol-maleimide adducts was also shown as an alternative initiation pathway for maleimide polymerization in polar solvents. Ultimately, optimal “one-pot” reaction conditions were identified allowing for up to 99% maleimide end-group functionalization of dithiobenzoate-terminated poly(N,N-dimethylacrylamide). Much of the work described herein can also be used to ensure near-quant. conversion of small mol. thiol-maleimide reactions while preventing previously unforeseen side reactions.

Macromolecules (Washington, DC, United States) published new progress about 19788-49-9. 19788-49-9 belongs to esters-buliding-blocks, auxiliary class Thiol,Aliphatic hydrocarbon chain,Ester, name is Ethyl 2-mercaptopropanoate, and the molecular formula is C5H10O2S, Product Details of C5H10O2S.

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