Tag: 100-200

Characterization of key sulfur aroma compounds and enantiomer distribution in Yingjia Gongjiu was written by Zhu, JianCai;Niu, YunWei;Huang, Mingquan;Xiao, ZuoBing. And the article was included in LWT–Food Science and Technology in 2022.SDS of cas: 659-70-1 This article mentions the following:

Yingjia Gongjiu (YJGJ), as a strong-aroma-type baijiu, is popular among consumers due to its unique fruity flavor. However, previous research on the aroma characteristics of YJGJ mostly focused on its main aroma components, namely the esters, therefore, the present work was the first to study the aroma characteristics of YJGJ from the perspective of sulfur-containing compounds A total of 12 sulfur-containing compounds were identified. Among them, 4-methyl-4-mercapto-2-pentanone, 2-methyl-3-furanthiol, 3-mercaptohexyl acetate, di-Me disulfide, di-Me trisulfide, and methional were among the key contributors to the aroma of YJGJ. Meanwhile, 14 enantiomers were identified. Among them, (R)-(-)-3-mercaptohexyl acetate, (R)-(-)-3-mercapto-2-butanone, (R)-(-)-2-octyl butanoate, (S)-(+)-2-octyl butanoate, (R)-(-)-1-octen-3-ol, (R)-(-)-Et 2-methylbutanoate and (R)-(-)-phenylethyl 2-methylbutanoate made an important contribution to the aroma of YJGJ. This research may provide an important theor. basis for the quality improvement and quality identification of YJGJ and other strong-aroma-types of baijiu. In the experiment, the researchers used many compounds, for example, Isopentyl 3-methylbutanoate (cas: 659-70-1SDS of cas: 659-70-1).

Isopentyl 3-methylbutanoate (cas: 659-70-1) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Liquid esters of low volatility serve as softening agents for resins and plastics. Esters also include many industrially important polymers. Polymethyl methacrylate is a glass substitute sold under the names Lucite and Plexiglas; polyethylene terephthalate is used as a film (Mylar) and as textile fibres sold as Terylene, Fortrel, and Dacron.SDS of cas: 659-70-1

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Synthesis and effect of potential drugs. Part 10. Reaction of furfural with methyl anthranilate and methyl 2-aminonicotinate was written by Reisch, Johannes;Mahran, M. Refat. And the article was included in Archiv der Pharmazie (Weinheim, Germany) in 1977.Reference of 14667-47-1 This article mentions the following:

Treatment of furfural with 2-H2NC6H4CO2Me in MeOH gave 38% 2,4- (I) and 18% 4,5-bis[o-(methoxycarbonyl)anilino]-2-cyclopenten-1-one; in Et2O, the yields were 36 and 25%, resp. With Me 2-aminonicotinate in absolute MeOH, furfural gave 75% di-Me 2,2′-(furfurylidenediimino)dinicotinate. Condensation of I with BzH gave 85% 5-benzylidene-2,4-bis[o-(methoxycarbonyl)anilino]-2-cyclopenten-1-one. In the experiment, the researchers used many compounds, for example, Methyl 2-aminonicotinate (cas: 14667-47-1Reference of 14667-47-1).

Methyl 2-aminonicotinate (cas: 14667-47-1) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Reference of 14667-47-1

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Characterization of volatile organic compounds of healthy and huanglongbing-infected navel orange and pomelo leaves by HS-GC-IMS was written by Cao, Shan;Sun, Jingyu;Yuan, Xiaoyong;Deng, Weihui;Zhong, Balian;Chun, Jiong. And the article was included in Molecules in 2020.Safety of Methyl2-methylbutyrate This article mentions the following:

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is the only natural vector of bacteria responsible for Huanglongbing (HLB), a worldwide destructive disease of citrus. ACP reproduces and develops only on the young leaves of its rutaceous host plants. Olfactory stimuli emitted by young leaves may play an important role in ACP control and HLB detection. In this study, volatile organic compounds (VOCs) from healthy and HLB-infected young leaves of navel orange and pomelo were analyzed by headspace-gas chromatog.-ion mobility spectrometry (HS-GC-IMS). A total of 36 compounds (including dimers or polymers) were identified and quantified from orange and 10 from pomelo leaves. Some compounds showed significant differences in signal intensity between healthy and HLB-infected leaves and may constitute possible indicators for HLB infection. Principal component anal. (PCA) clearly discriminated healthy and HLB-infected leaves in both orange and pomelo. HS-GC-IMS was an effective method to identify VOCs from leaves. This study may help develop new methods for detection of HLB or find new attractants or repellents of ACP for prevention of HLB. In the experiment, the researchers used many compounds, for example, Methyl2-methylbutyrate (cas: 868-57-5Safety of Methyl2-methylbutyrate).

Methyl2-methylbutyrate (cas: 868-57-5) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Acyl chlorides and acid anhydrides alcoholysis is another way to produce esters. Acyl chlorides and acid anhydrides react with alcohols to produce esters. Anydrous conditions are recommended since both acyl chlorides and acid anhydrides react with water.Safety of Methyl2-methylbutyrate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Divergent Dynamic Kinetic Resolution of a Racemic Mixture of Four Stereoisomers via N-Heterocyclic Carbene Organocatalysis was written by Vasamsetty, Laxmaiah;Kong, Xiangwen;Meng, Miao;Yang, Shuang;Xu, Weici;Reddy, Pogula Sreekanth;Fang, Xinqiang. And the article was included in Chemistry – An Asian Journal in 2018.Product Details of 13669-10-8 This article mentions the following:

Racemic mixtures of four stereoisomers are easily formed via many fundamental organic transformations, but the direct utilities of these mixtures were less studied and remain large challenges to date. The authors introduce a new method, i.e., divergent dynamic kinetic resolution, to achieve the separation of racemic mixtures of four stereoisomers. The hypothesis was proved by using a N-heterocyclic carbene-catalyzed benzoin reaction, which afforded two separable diastereomeric products bearing three consecutive stereocenters with good to excellent enantioselectivities. The authors believe that this resolution protocol will find applications in more transformations. In the experiment, the researchers used many compounds, for example, Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8Product Details of 13669-10-8).

Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Product Details of 13669-10-8

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Cationic Palladium-Catalyzed Hydrosilylative Cross-Coupling of Alkynes with Alkenes was written by Shimamoto, Takamitsu;Chimori, Motoharu;Sogawa, Hiroaki;Yamamoto, Keiji. And the article was included in Journal of the American Chemical Society in 2005.Reference of 17920-23-9 This article mentions the following:

A cationic palladium complex-catalyzed cross-coupling of alkynes with alkenes is presented, which occurs selectively under the hydrosilylation conditions using trichlorosilane. The unique reaction might be well understood in terms of an initial hydropalladation of a given 1-alkyne to form regioselectively a 1-alkenylpalladium species, which, in turn, undergoes easily and specifically an alkene insertion. The resulting homoallylic organopalladium species terminates one catalytic cycle by substituting the palladium center with a trichlorosilyl group to give product(s). In the experiment, the researchers used many compounds, for example, Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9Reference of 17920-23-9).

Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. Acyl chlorides and acid anhydrides alcoholysis is another way to produce esters. Acyl chlorides and acid anhydrides react with alcohols to produce esters. Anydrous conditions are recommended since both acyl chlorides and acid anhydrides react with water.Reference of 17920-23-9

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Enantioselective α-Amination of Acyclic 1,3-Dicarbonyls Catalyzed by N-Heterocyclic Carbene was written by Santra, Surojit;Maji, Ujjwal;Guin, Joyram. And the article was included in Organic Letters in 2020.HPLC of Formula: 13669-10-8 This article mentions the following:

Herein, we describe a method for the catalytic enantioselective α-amination of α-substituted acyclic 1,3-ketoamides and 1,3-amidoesters that affords the products possessing N-substituted quaternary stereocenters with a chiral N-heterocyclic carbene (NHC). The reaction is based on the utilization of an intrinsic Bronsted base characteristic of NHC that enables the catalytic formation of a chiral ion pair comprising the enolate and the azolium ion. A series of challenging open-chain α-substituted 1,3-dicarbonyls are aminated via this method with ee’s of ≤99%. In the experiment, the researchers used many compounds, for example, Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8HPLC of Formula: 13669-10-8).

Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.HPLC of Formula: 13669-10-8

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Biomarker Metabolites Discriminate between Physiological States of Field, Cave and White-nose Syndrome Diseased Bats was written by Doty, Anna C.;Wilson, A. Dan;Forse, Lisa B.;Risch, Thomas S.. And the article was included in Sensors in 2022.Category: esters-buliding-blocks This article mentions the following:

Anal. of volatile organic compound (VOC) emissions using electronic-nose (e-nose) devices has shown promise for early detection of white-nose syndrome (WNS) in bats. Tricolored bats, Perimyotis subflavus, from three sep. sampling groups defined by environmental conditions, levels of phys. activity, and WNS-disease status were captured temporarily for collection of VOC emissions to determine relationships between these combinations of factors and physiol. states, Pseudogymnoascus destructans (Pd)-infection status, and metabolic conditions. Physiol. active (non-torpid) healthy individuals were captured outside of caves in Arkansas and Louisiana. In addition, healthy and WNS-diseased torpid bats were sampled within caves in Arkansas. Whole-body VOC emissions from bats were collected using portable air-collection and sampling-chamber devices in tandem. Electronic aroma-detection data using three-dimensional Principal Component Anal. provided strong evidence that the three groups of bats had significantly different e-nose aroma signatures, indicative of different VOC profiles. This was confirmed by differences in peak numbers, peak areas, and tentative chem. identities indicated by chromatograms from dual-column GC-analyses. The numbers and quantities of VOCs present in whole-body emissions from physiol. active healthy field bats were significantly greater than those of torpid healthy and diseased cave bats. Specific VOCs were identified as chem. biomarkers of healthy and diseased states, environmental conditions (outside and inside of caves), and levels of physiol. activity. These results suggest that GC/E-nose dual-technologies based on VOC-detection and analyses of physiol. states, provide noninvasive alternative means for early assessments of Pd-infection, WNS-disease status, and other physiol. states. In the experiment, the researchers used many compounds, for example, 5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9Category: esters-buliding-blocks).

5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries. Liquid esters of low volatility serve as softening agents for resins and plastics. Esters also include many industrially important polymers. Polymethyl methacrylate is a glass substitute sold under the names Lucite and Plexiglas; polyethylene terephthalate is used as a film (Mylar) and as textile fibres sold as Terylene, Fortrel, and Dacron.Category: esters-buliding-blocks

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Cu(I)-NHC-Catalyzed (2 + 3)-Annulation of Tetramic Acids with 2H-Azirines: Stereoselective Synthesis of Functionalized Hexahydropyrrolo[3,4-b]pyrroles was written by Rostovskii, Nikolai V.;Sakharov, Pavel A.;Novikov, Mikhail S.;Khlebnikov, Alexander F.;Starova, Galina L.. And the article was included in Organic Letters in 2015.Category: esters-buliding-blocks This article mentions the following:

A stereoselective and high-yield synthesis of hexahydropyrrolo[3,4-b]pyrroles I [R¹ = PMB, H, Bn, Ph, Ac, etc.; R² = H, Me; R¹R² = (CH₂)₃; R³ = Ph, 4-ClC₆H₄, 4-OMeC₆H₄, CO₂Me, 2-thienyl; R⁴ = 4-MeC₆H₄, 4-OMeC₆H₄, 4-NO₂C₆H₄, Ph; R⁵ = H, Me, Ph] from tetramic acids and 2H-azirines under Cu(I)-NHC catalysis is developed. An unusual N-C2 azirine bond cleavage, initiated by a copper enolate, was rationalized in terms of a free radical reaction mechanism. In the experiment, the researchers used many compounds, for example, Methyl 2-thienylacetate (cas: 19432-68-9Category: esters-buliding-blocks).

Methyl 2-thienylacetate (cas: 19432-68-9) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Category: esters-buliding-blocks

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Pushing the Limits of Detection of Weak Binding Using Fragment-Based Drug Discovery: Identification of New Cyclophilin Binders was written by Georgiou, Charis;McNae, Iain;Wear, Martin;Ioannidis, Harris;Michel, Julien;Walkinshaw, Malcolm. And the article was included in Journal of Molecular Biology in 2017.Computed Properties of C7H8N2O2 This article mentions the following:

Fragment-based drug discovery is an increasingly popular method to identify novel small-mol. drug candidates. One of the limitations of the approach is the difficulty of accurately characterizing weak binding events. This work reports a combination of X-ray diffraction, surface plasmon resonance experiments and mol. dynamics simulations for the characterization of binders to different isoforms of the cyclophilin (Cyp) protein family. Although several Cyp inhibitors have been reported in the literature, it has proven challenging to achieve high binding selectivity for different isoforms of this protein family. The present studies have led to the identification of several structurally novel fragments that bind to diverse Cyp isoforms in distinct pockets with low millimolar dissociation constants A detailed comparison of the merits and drawbacks of the exptl. and computational techniques is presented, and emerging strategies for designing ligands with enhanced isoform specificity are described. In the experiment, the researchers used many compounds, for example, Methyl 2-aminonicotinate (cas: 14667-47-1Computed Properties of C7H8N2O2).

Methyl 2-aminonicotinate (cas: 14667-47-1) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.Computed Properties of C7H8N2O2

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Improvement of the activity of arylmalonate decarboxylase by random mutagenesis was written by Terao, Y.;Miyamoto, K.;Ohta, H.. And the article was included in Applied Microbiology and Biotechnology in 2006.Formula: C7H8O2S This article mentions the following:

Arylmalonate decarboxylase (EC 4.1.1.76) catalyzes enantioselective decarboxylation of α-aryl-α-methylmalonates to give optically pure α-arylpropionates. Recently, we have succeeded in creating a double mutant enzyme that gave opposite enantionmer as the product. Unfortunately, however, the activity of the mutant decreased far lower than that of the native enzyme. Thus, we performed the directed evolution of the mutant via the random mutagenesis method employing the mutator strain Escherichia coli XL1-Red. About 50,000 mutants were screened on color assay plate, and one mutant with higher activity was obtained. Gene anal. of this mutant indicated that the obtained enzyme had an S36N mutation in addition to its original G74C/C188S mutations. The activity of the triple mutant enzyme was tenfold higher than that of the starting doubly mutated enzyme. In the experiment, the researchers used many compounds, for example, Methyl 2-thienylacetate (cas: 19432-68-9Formula: C7H8O2S).

Methyl 2-thienylacetate (cas: 19432-68-9) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.Formula: C7H8O2S

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics