Tag: M.W=200-250

Lopez-Velazquez, Delia published the artcileStructure and Phase Transitions of Ethyl-4′-n-undecyloxybiphenyl-4-carboxylate and Its Acid Derivative, SDS of cas: 50670-76-3, the publication is Molecular Crystals and Liquid Crystals (2008), 222-236, database is CAplus.

Ethyl-4′-n-undecyloxybiphenyl-4-carboxylate, 2(11)OBC, and 4′-n-undecyloxybiphenyl-4-carboxylic acid, (11)OBC, are smectic liquid crystals precursors of low mol. weight premesogens, and of potential liquid crystal macromols. The single-crystal X-ray study of 2(11)OBC showed that it crystallizes in a non-centrosym. space group with mols. stacked along the short axis [010] and [001] without significant π···π or CH···π interactions. Such an arrangement may explain its strong tendency to form smectic mesophases. Both biphenyl derivatives have a rich polymesomorphism whose phase sequences were determined by DSC, optical microscopy and diffraction profiles using synchrotron radiation. These profiles indicated quite similar phase transitions in the two samples, although very different transition temperatures The phase transitions (on cooling) of 2(11)OBC are: Isotropic → SmA (101°) → SmB (88°) → SE (79°) → crystal phase (43°), while those (on cooling) of (11)OBC are the following: Isotropic → SmA (246°) → SmB (192°) → SX (162°) → SE (148°) → crystal phase (62°). The much higher transition temperatures for the acid derivative are explained by considering that this mol. forms dimers through classical O-H···O hydrogen bonds involving the carboxylic groups.

Molecular Crystals and Liquid Crystals published new progress about 50670-76-3. 50670-76-3 belongs to esters-buliding-blocks, auxiliary class Benzene,Phenol,Ester, name is Ethyl 4′-hydroxy-[1,1′-biphenyl]-4-carboxylate, and the molecular formula is C15H14O3, SDS of cas: 50670-76-3.

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

Toral, P. G. published the artcileEffect of lipid supplementation on the endogenous synthesis of milk cis-9,trans-11 conjugated linoleic acid in dairy sheep and goats: A tracer assay with 13c-vaccenic acid, Related Products of esters-buliding-blocks, the publication is Journal of Dairy Science (2022), 105(1), 255-268, database is CAplus and MEDLINE.

A major proportion of milk rumenic acid (RA; cis-9,trans-11 CLA) is synthesized through mammary Δ9-desaturation of vaccenic acid (VA; trans-11 18:1). Diet composition may determine the relative contribution of this endogenous synthesis to milk RA content, with effects that might differ between ruminant species. However, this hypothesis is mostly based on estimated values, proxies of stearoyl-CoA desaturase (SCD) activity, and indirect comparisons between publications in the literature. With the aim of providing new insights into this issue, in vivo Δ9-desaturation of 13C-labeled VA (measured via milk 13C-VA and -RA secretion) was directly compared in sheep and goats fed a diet without lipid supplementation or including 2% of linseed oil. Four Assaf sheep and 4 Murciano-Granadina goats were used in a replicated 2 x 2 crossover design to test the effects of the 2 dietary treatments during 2 consecutive 25-d periods. On d 22 of each period, 500 mg of 13C-VA were i.v. injected to each animal. Dairy performance, milk fatty acid profile, including isotope anal., and mammary mRNA abundance of genes coding for SCD were examined on d 21 to 25 of each period. Supplementation with linseed oil improved milk fat concentration and increased the content of milk VA and RA. However, the isotopic tracer assay suggested no variation in the relative proportion of VA desatd. to milk RA, and the percentage of this CLA isomer deriving from SCD activity would remain constant regardless of dietary treatment. These results put into question a major effect of lipid supplementation on the endogenous synthesis of milk RA and support that mammary Δ9-desaturation capacity would not represent a limiting factor when designing feeding strategies to increase milk RA content. The lack of diet-induced effects was common to caprines and ovines, but inherent interspecies differences in mammary lipogenesis were found. Thus, the higher proportions of VA desaturation and endogenous synthesis of milk RA in sheep supported a greater SCD activity compared with goats, a finding that was not associated with the similar mRNA abundance of SCD1 in the 2 species. On the other hand, transfer efficiency of the isotopic tracer to milk was 37% higher in caprine than in ovine, suggesting a greater efficiency in mammary fatty acid uptake from plasma in caprine.

Journal of Dairy Science published new progress about 121-79-9. 121-79-9 belongs to esters-buliding-blocks, auxiliary class Natural product, name is Propyl 3,4,5-trihydroxybenzoate, and the molecular formula is C11H15NO2, Related Products of esters-buliding-blocks.

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

Mascellani, Anna published the artcile¹H NMR chemometric models for classification of Czech wine type and variety, SDS of cas: 121-79-9, the publication is Food Chemistry (2021), 127852, database is CAplus and MEDLINE.

A set of 917 wines of Czech origin were analyzed using NMR spectroscopy (NMR) with the aim of building and evaluating multivariate statistical models and machine learning methods for the classification of 6 types based on color and residual sugar content, 13 wine grape varieties and 4 locations based on 1H NMR spectra. The predictive models afforded greater than 93% correctness for classifying dry and medium dry, medium, and sweet white wines and dry red wines. The trained Random Forest (RF) model classified Pinot noir with 96% correctness, Blaufrankisch 96%, Riesling 92%, Cabernet Sauvignon 77%, Chardonnay 76%, Gewurtztraminer 60%, Hibernal 60%, Gruner Veltliner 52%, Pinot gris 48%, Sauvignon Blanc 45%, and Palava 40%. Pinot blanc and Chardonnay, varieties that are often mistakenly interchanged, were discriminated with 71% correctness. The findings support chemometrics as a tool for predicting important features in wine, particularly for quality assessment and fraud detection.

Food Chemistry published new progress about 121-79-9. 121-79-9 belongs to esters-buliding-blocks, auxiliary class Natural product, name is Propyl 3,4,5-trihydroxybenzoate, and the molecular formula is C10H12O5, SDS of cas: 121-79-9.

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

Nagasawa, Kinzo published the artcileReductive cleavage of sulfur-containing carbamates with Raney nickel, Application of Benzyl diethylcarbamodithioate, the publication is Chemical & Pharmaceutical Bulletin (1975), 23(10), 2454-8, database is CAplus.

The reductive cleavage of Et2NC(O)SCH2C6H4Cl-4 gave HCONEt2, PhMe, and HCl; PhMe and Et2NMe were obtained from Et2NCS2CH2Ph. The reaction of PhNHC(S)OMe in EtOH gave N-ethyl-N-methylcyclohexylamine, N-ethylcyclohexylamine, and N,N-diethylcyclohexylamine.

Chemical & Pharmaceutical Bulletin published new progress about 3052-61-7. 3052-61-7 belongs to esters-buliding-blocks, auxiliary class Amine,Benzene,Amide, name is Benzyl diethylcarbamodithioate, and the molecular formula is C12H17NS2, Application of Benzyl diethylcarbamodithioate.

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

Yamamoto, Takeshi published the artcileSynthesis and quantitative structure-activity relationships of N-(3-oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-carbonyl)guanidines as Na/H exchange inhibitors, Product Details of C11H11NO4, the publication is Chemical & Pharmaceutical Bulletin (1998), 46(11), 1716-1723, database is CAplus and MEDLINE.

N-(3-Oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-carbonyl)guanidines I [R = H, Cl, OMe; R¹ = H, Me; R² = H, Me, Et, Ph; R³ = H, Me, Et, CHMe₂, Pr, Bu, CH₂CH₂OEt, hexyl] were prepared and tested for Na/H exchange inhibitory activities in order to clarify the structure-activity relationship (SAR). QSAR anal. of I indicated that the length of the 4-substituent was parabolically related to activity and that the calculated optimum 4-substituents were Pr, Et and iso-Pr groups. This SAR was similar to the SAR of the 2- and 4-substituents of 7-carbonylguanidine derivatives, although the position relative to the essential guanidinocarbonyl group was different. Larger 2-substituents, such as a Ph group were unfavorable. The most potent derivative in this series was I [R = H, R¹, R² = Me, R³ = CHMe₂] with an IC₅₀ value of 0.12 μM. The methanesulfonate salt (KB-R9032) of this compound had excellent water-solubility and showed anti-arrhythmic activity against a rat acute myocardial infarction model. KB-R9032 was selected for further investigation as a therapy for ischemia-reperfusion induced injury.

Chemical & Pharmaceutical Bulletin published new progress about 179950-77-7. 179950-77-7 belongs to esters-buliding-blocks, auxiliary class Other Aromatic Heterocyclic,Ester,Amide, name is Methyl 2-methyl-3-oxo-3,4-dihydro-2H-benzo[b][1,4]oxazine-6-carboxylate, and the molecular formula is C7H10BNO3, Product Details of C11H11NO4.

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

Koutek, Bohumir published the artcileGas chromatographic determination of vapor pressures of pheromone-like acetates, Application In Synthesis of 16974-11-1, the publication is Journal of Chromatography (1992), 626(2), 215-21, database is CAplus.

The vapor pressures of nineteen Z and E monounsaturated C₁₀-C₁₆ even-carbon acetates were determined using a method based on gas chromatog. (GC) retention data. Exptl. measurements were carried out at six temperatures in the range 90-140° on a 2-m HP-1 capillary column by utilizing n-C₁₈ and n-C₂₀ hydrocarbons as vapor pressure reference compounds Corrections for the systematic errors were made by relating the exptl. determined vapor pressures P_GC to the literature values P_L through a linear regression relationship. Over a narrow temperature range of 25-45°, the GC-measured vapor pressures were found to satisfy the Clausius-Clapeyron equation. Also, for structurally similar subseries of acetates, e.g., for ω – 3 or ω – 5 unsaturated derivatives, the vapor pressures were shown to have a simple dependence on the number of carbon atoms per mol. The vapor pressures at 25° ranged from 2.633 Pa for (Z)-5-decenyl acetate to 0.005 Pa for (E)-13-hexadecenyl acetate.

Journal of Chromatography 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, Application In Synthesis of 16974-11-1.

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

Kutsumizu, Shoichi published the artcileSmectic C to Cubic Phase Transition of 4′-n-Docosyloxy-3′-nitrobiphenyl-4-carboxylic Acid (ANBC-22) and Alternating-Current Electric Field Effect, COA of Formula: C15H14O3, the publication is Journal of Physical Chemistry B (2009), 113(3), 640-646, database is CAplus and MEDLINE.

Smectic C (SmC) to cubic (Cub) phase transition behavior of 4′-n-docosyloxy-3′-nitrobiphenyl-4-carboxylic acid (ANBC-22) and alternating-current (AC) elec. field effect on the SmC phase were examined The most important and unexpected finding is that even at a temperature 8 K below the zero-field SmC to Cub phase transition temperature (T_SmC-Cub ≈ 408 K) determined previously for the compound and without field, the Cub phase growth occurs, after a very long induction period of several hours. The X-ray diffraction measurements revealed the formation of an Im3m-type Cub phase at the temperature It is suggested that the “true” transition temperature, which is difficult to determine precisely, exists around 396 K. The time-dependence of the Cub phase growth both without field and under field was analyzed using the well-known Avrami equation, implying the nucleation and growth mechanism mainly operating in the SmC to Cub phase transformation. The fact uncovered is that between 408 and 396 K, the SmC to Cub transformation is virtually prohibited by the strongly limited nucleation. It is concluded that the effect of the elec. field on the transition is to promote the nucleation of the Cub phase in the temperature region where the Cub phase is potentially more stable than the precursory SmC phase.

Journal of Physical Chemistry B published new progress about 50670-76-3. 50670-76-3 belongs to esters-buliding-blocks, auxiliary class Benzene,Phenol,Ester, name is Ethyl 4′-hydroxy-[1,1′-biphenyl]-4-carboxylate, and the molecular formula is C15H14O3, COA of Formula: C15H14O3.

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

Zhou, Yanwu published the artcileDependence of Thermal Stability on Molecular Structure of RAFT/MADIX Agents: A Kinetic and Mechanistic Study, Name: Benzyl diethylcarbamodithioate, the publication is Macromolecules (Washington, DC, United States) (2011), 44(21), 8446-8457, database is CAplus.

The thermal decomposition of different classes of RAFT/MADIX agents, namely dithioesters, trithiocarbonates, xanthates, and dithiocarbamates, were studied through heating in solution The decomposition behavior is complicated interplay of the effects of stabilizing Z-group and leaving R-group. The mechanism of the decomposition is mainly through three pathways, i.e., β-elimination, α-elimination, and homolysis of dithiocarbamate (particularly for universal RAFT agent). The most important pathway is the β-elimination of thiocarbonylthio compounds possessing β-hydrogen, leading to the formation unsaturated species. For the leaving group containing solely α-hydrogen, such as benzyl, α-elimination takes place, resulting in the formation of (E)-stilbene through a carbene intermediate. Homolysis occurs specifically in the case of a universal RAFT agent, in which a thiocarbonyl radical and an alkylthio radical are generated, finally forming thiolactone through a radical process. The stabilities of the RAFT/MADIX agents are studied by measuring the apparent kinetics and activation energy of the thermal decomposition reactions. Both Z-group and R-group influence the stability of the agents through electronic and steric effects. Lone pair electron donating heteroatoms of Z-group show a remarkable stabilizing effect while electron withdrawing substituents, either in Z- or R-group, tends to destabilize the agent. In addition, bulkier or more β-hydrogens result in faster decomposition rate or lower decomposition temperature Thus, the stability of the RAFT/MAIDX agents decreases in the order where R is (with identical Z = phenyl) -CH₂Ph (5) >-PS (PS-RAFT 15) > -C(Me)HPh (2) >-C(Me)₂C(=O)OC₂H₅ (7) >-C(Me)₂Ph(1) > -PMMA (PMMA-RAFT 16) > -C(Me)₂CN (6). For those possessing identical leaving group such as 1-phenylethyl, the stability decreases in the order of O-Et (11) > -N(CH₂CH₃)₂ (13) > -SCH(CH₃)Ph (8) > -Ph (2) > -CH₂Ph (4) > -PhNO₂ (3). These results consort with the chain transfer activities measured by the CSIRO group and agree well with the ab initio theor. results by Coote. In addition, the difference between thermal stabilities of the universal RAFT agents at neutral and protonated states was demonstrated.

Macromolecules (Washington, DC, United States) published new progress about 3052-61-7. 3052-61-7 belongs to esters-buliding-blocks, auxiliary class Amine,Benzene,Amide, name is Benzyl diethylcarbamodithioate, and the molecular formula is C12H17NS2, Name: Benzyl diethylcarbamodithioate.

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

Abedi, Abdol-Samad published the artcileApplication of thermal ultrasound-assisted liquid-liquid micro-extraction coupled with HPLC-UV for rapid determination of synthetic phenolic antioxidants in edible oils, Application In Synthesis of 121-79-9, the publication is Journal of the American Oil Chemists’ Society (2021), 98(10), 969-978, database is CAplus.

A simple, fast, and reliable liquid-liquid micro-extraction (LLME) method assisted by thermal ultrasound approach was developed for simultaneous determination of synthetic phenolic antioxidants (SPAs) in edible oils by high-performance liquid chromatog. equipped with UV detector (HPLC-UV). The synthetic antioxidants were Pr gallate (PG), butylated hydroxyanisole (BHA), tert-butylhydroquinone (TBHQ), and butylated hydroxyltoluene (BHT). The best extraction conditions were observed were methanol/acetonitrile (1:1, volume/volume) as the solvent, ultrasound at 4 min, and a temperature of 40°C. The linearity of the calibration curves for the optimum conditions were R² > 0.989 for all of the SPAs in a range from 1-200μ g ml^-1. Relative standard deviation (RSD%) for five anal. was in range of 2.83% to 4.21%. Limit of detection (LOD) and limit of quantification (LOQ) were obtained in range of 0.012-0.06 and 0.04-0.2μ g g^-1, resp. With regard to recovery, a range of 91%-116% was calculated for the spiked edible oils.

Journal of the American Oil Chemists’ Society published new progress about 121-79-9. 121-79-9 belongs to esters-buliding-blocks, auxiliary class Natural product, name is Propyl 3,4,5-trihydroxybenzoate, and the molecular formula is C10H12O5, Application In Synthesis of 121-79-9.

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

Said, Ahmed M. published the artcileBinding cooperativity between a ligand carbonyl group and a hydrophobic side chain can be enhanced by additional H-bonds in a distance dependent manner: A case study with thrombin inhibitors, Application of (R)-tert-Butyl (3-methyl-1-oxobutan-2-yl)carbamate, the publication is European Journal of Medicinal Chemistry (2015), 405-424, database is CAplus and MEDLINE.

One of the underappreciated non-covalent binding factors, which can significantly affect ligand-protein binding affinity, is the cooperativity between ligand functional groups. Using four different series of thrombin inhibitors, we reveal a strong pos. cooperativity between an H-bond accepting carbonyl functionality and the adjacent P3 hydrophobic side chain. Adding an H-bond donating amine adjacent to the P3 hydrophobic side chain further increases this pos. cooperativity thereby improving the K_i by as much as 546-fold. In contrast, adding an amidine multiple H-bond/salt bridge group in the distal S1 pocket does not affect this cooperativity. An anal. of the crystallog. B-factors of the ligand groups inside the binding site indicates that the strong cooperativity is mainly due to a significant mutual reduction in the residual mobility of the hydrophobic side chain and the H-bonding functionalities that is absent when the separation distance is large. This type of cooperativity is important to encode in binding affinity prediction software, and to consider in SAR studies.

European Journal of Medicinal Chemistry published new progress about 106391-88-2. 106391-88-2 belongs to esters-buliding-blocks, auxiliary class Amine,Aliphatic hydrocarbon chain,Amide,Aldehyde, name is (R)-tert-Butyl (3-methyl-1-oxobutan-2-yl)carbamate, and the molecular formula is C10H19NO3, Application of (R)-tert-Butyl (3-methyl-1-oxobutan-2-yl)carbamate.

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