Day: November 21, 2022

Hartman, Guy J. published the artcileVolatile products of the reaction of sulfur-containing amino acids with 2,3-butanedione, COA of Formula: C5H7NO, the publication is Lebensmittel-Wissenschaft und -Technologie (1984), 17(3), 171-4, database is CAplus.

The Strecker degradation reactions of the S-containing amino acids, cysteine  [52-90-4], cystine  [56-89-3], and methionine  [63-68-3] with 2,3-butanedione  [431-03-8] were studied. Many heterocyclic compounds including pyrazines, oxazoles, thiazoles, pyrroles, and thiophenes were identified.

Lebensmittel-Wissenschaft und -Technologie published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, COA of Formula: C5H7NO.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Salinas, Juan P. published the artcileLipid-derived aroma compounds in cooked potatoes and reconstituted dehydrated potato granules, Safety of 4,5-Dimethyloxazole, the publication is ACS Symposium Series (1994), 108-29, database is CAplus.

Volatile compounds that contribute to flavor of steam cooked mashed potatoes and reconstituted dehydrated potato granules were characterized. Aroma components were isolated and concentrated using continuous steam distillation – extraction procedures and/or by dynamic headspace concentration using porous polymer adsorbent trapping media. The steam distillation extracts and adsorbent traps were subsequently analyzed by gas chromatog. – mass spectrometry (GC-MS), the latter using short path thermal desorption methodol. Quantification was achieved using matrix-spiked internal standard methodol. Comparison of the two isolation techniques revealed both qual. and quant. differences in the extracted profiles which were highly reproducible. The purge and trap – thermal desorption methodol. produced GC-MS chromatograms with enhanced recoveries of light end components while the steam distillation extracts contained greater amounts of higher boiling semivolatile species.

ACS Symposium Series published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, Safety of 4,5-Dimethyloxazole.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Hwang, Hui-Ing published the artcileRelative Reactivities of Amino Acids in the Formation of Pyridines, Pyrroles, and Oxazoles, Application In Synthesis of 20662-83-3, the publication is Journal of Agricultural and Food Chemistry (1995), 43(11), 2917-21, database is CAplus.

The contributions of ¹⁵N-labeled glycine and tested amino acids (glutamine, glutamic acid, asparagine, aspartic acid, lysine, arginine, phenylalanine, and isoleucine) to pyridine, pyrrole, and oxazole formation were investigated. Ten pyridines, nine pyrroles, two oxazoles, three amines, and one benzonitrile were identified in the present study. The quantities of pyridines, pyrroles, and oxazoles in the reaction mixture of glycine and aspartic acid were the highest. Aspartic acid, lysine, and asparagine had the highest contribution in pyridine, pyrrole, and oxazole formation, resp. In the presence of glycine, glutamic acid showed the least contribution, whereas asparagine had the highest contribution to the formation of all nitrogen-containing compounds among the tested amino acids. While lysine was able to increase the reactivity of glycine, arginine inhibited the capability of glycine to produce nitrogen-containing volatile compounds

Journal of Agricultural and Food Chemistry published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, Application In Synthesis of 20662-83-3.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Ho, Chi Tang published the artcileFormation of oxazolines and oxazoles in Strecker degradation of DL-alanine and L-cysteine with 2,3-butanedione, Product Details of C5H7NO, the publication is Journal of Agricultural and Food Chemistry (1982), 30(4), 793-4, database is CAplus.

2,4,5-trimethyl-3-oxazoline  [22694-96-8] And 2,4,5-trimethyloxazole  [20662-84-4] were identified in the reaction mixture of DL-alanine  [302-72-7] and 2,3-butanedione  [431-03-8]. 2,4,5-Trimethyloxazole and 4,5-dimethyloxazole  [20662-83-3] were identified in the reaction mixture of L-cysteine  [52-90-4] and 2,3-butanedione. Mechanisms are proposed for the formation of these oxazoles and oxazolines, and their role in food flavor is discussed.

Journal of Agricultural and Food Chemistry published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, Product Details of C5H7NO.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Kubota, Etsuro published the artcileOxazoles and pyrazines identified in roasted green tea aroma, Recommanded Product: 4,5-Dimethyloxazole, the publication is Chagyo Gijutsu Kenkyu (1983), 59-61, database is CAplus.

From the basis fraction of roasted green tea, 2 oxazoles, 14 alkylpyrazines, 3 cyclopentapyrazines, and 4 furan compounds were separated The 2 oxazoles were identified as 4,5-dimethyloxazole  [20662-83-3] and 2,4,5-trimethyloxazole  [20662-84-4] by gas chromatog.-mass spectrometry. Alkylpyrazines constituted �0% of the volatiles in the basic fraction.

Chagyo Gijutsu Kenkyu published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, Recommanded Product: 4,5-Dimethyloxazole.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Lu, Chih-ying published the artcileEffects of water content on volatile generation and peptide degradation in the Maillard reaction of glycine, diglycine, and triglycine, Safety of 4,5-Dimethyloxazole, the publication is Journal of Agricultural and Food Chemistry (2005), 53(16), 6443-6447, database is CAplus and MEDLINE.

Peptides abundant in food and protein hydrolyzates are known to be important to process flavors. The present study reports the volatile profile of the Maillard reactions of glycine, diglycine, and triglycine. The reaction with glucose was conducted at 0-100% water content in glycerol medium at 160° for 1 h. Volatile compounds were quantified by stir bar sorptive extraction-gas chromatog.-mass spectrometry, and nonvolatile compounds were quantified by high-performance liquid chromatog.-tandem mass spectrometry. The major volatiles produced from each of the reaction systems were trimethylpyrazine and 2,5-dimethylpyrazine. Volatile generation increased as water decreased, and the overall reactivity of the glycine and glycine peptides in volatile formation was glycine â‰?triglycine > diglycine. Triglycine was very unstable and mainly degraded into cyclic Gly-Gly and glycine, whereas diglycine had a higher stability than triglycine toward hydrolytic cleavage of the peptide bond. The amounts of glycine, diglycine, cyclic (Gly-Gly), and triglycine in the peptide-glucose reaction mixtures at different water content were reported.

Journal of Agricultural and Food Chemistry published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, Safety of 4,5-Dimethyloxazole.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Yaylayan, Varoujan A. published the artcileMechanism of imidazole and oxazole formation in [¹³C-2]-labelled glycine and alanine model systems, Category: oxazolidine, the publication is Food Chemistry (2003), 81(3), 403-409, database is CAplus.

Studies with ¹³C-2-labeled glycine and alanine in model systems containing 2,3-butanedione, glyceraldehyde or glyoxal have indicated that imidazoles and oxazoles can be formed from α-dicarbonyl compounds through Strecker reaction and subsequent formation of α-amino carbonyl reactive intermediates. These intermediates can react with any aldehyde in the reaction mixture to form an imine which in turn can either cyclize to form oxazoles or react with an amino compound and then cyclize to form imidazole after an oxidation step. On the other hand, Amadori products, formed in α-hydroxycarbonyl containing systems, can undergo decarboxylation followed by reaction with ammonia to form an amino imine intermediate which, after reaction with any aldehyde followed by cyclization, can form imidazoles after a dehydration step. This latter mechanism fixes the C-2 atom of glycine as an N-alkyl substituent in imidazoles. In addition, model studies with α-dicarbonyl compounds, using ammonium carbonate as a source of ammonia and paraformaldehyde as a source of formaldehyde, also produced imidazoles and oxazoles.

Food Chemistry published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H8N2O, Category: oxazolidine.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Ames, Jennifer M. published the artcileEffect of pH and Temperature on the Formation of Volatile Compounds in Cysteine/Reducing Sugar/Starch Mixtures during Extrusion Cooking, HPLC of Formula: 20662-83-3, the publication is Journal of Agricultural and Food Chemistry (2001), 49(4), 1885-1894, database is CAplus and MEDLINE.

Mixtures of cysteine, reducing sugar (xylose or glucose), and starch were extrusion cooked using feed pH values of 5.5, 6.5, and 7.5 and target die temperatures of 120, 150, and 180 °C. Volatile compounds were isolated by headspace trapping onto Tenax and analyzed by gas chromatog.-mass spectrometry. Eighty and 38 compounds, resp., were identified from extrudates prepared using glucose and xylose. Amounts of most compounds increased with temperature and pH. Aliphatic sulfur compounds, thiophenes, pyrazines, and thiazoles were the most abundant chem. classes for the glucose samples, whereas for xylose extrudates highest levels were obtained for non-sulfur-containing furans, thiophenes, sulfur-containing furans, and pyrazines. 2-Furanmethanethiol and 2-methyl-3-furanthiol were present in extrudates prepared using both sugars, but levels were higher in xylose samples. The profiles of reaction products were different from those obtained from aqueous or reduced-moisture systems based on cysteine and either glucose or ribose.

Journal of Agricultural and Food Chemistry published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, HPLC of Formula: 20662-83-3.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Ames, Jennifer M. published the artcileEffect of pH, Temperature, and Moisture on the Formation of Volatile Compounds in Glycine/Glucose Model Systems, Category: oxazolidine, the publication is Journal of Agricultural and Food Chemistry (2001), 49(9), 4315-4323, database is CAplus and MEDLINE.

Mixtures of glycine, glucose, and starch were extrusion cooked using sodium hydroxide at 0, 3, and 6 g/L of extruder water feed, 18% moisture, and 120, 150, and 180 °C target die temperatures, giving extrudates with pH values of 5.6, 6.8, and 7.4. Freeze-dried equimolar solutions of glucose and glycine were heated either dry or after equilibration to �3% moisture at 180°C in a reaction-tube system designed to mimic the heating profile in an extruder. Volatile compounds were isolated onto Tenax and analyzed by gas chromatog.-mass spectrometry. For the extrudates, total yields of volatiles increased with decreasing pH at 180°C, reached a maximum at pH 6.8 at 150°C, and increased with increasing pH at 120°C. Amounts increased with temperature at all pH values. Pyrazines were the most abundant class for all sets of conditions (54-79% of total volatiles). Pyrroles, ketones, furans, oxazoles, and pyridines were also identified. Yields of volatiles from the reaction-tube samples increased by >60% in the moist system. Levels of individual classes also increased in the presence of moisture, except pyrazines, which decreased �.5-fold. Twenty-one of the compounds were common to the reaction-tube samples and the extrudates.

Journal of Agricultural and Food Chemistry published new progress about 20662-83-3. 20662-83-3 belongs to oxazolidine, auxiliary class Oxazole, name is 4,5-Dimethyloxazole, and the molecular formula is C5H7NO, Category: oxazolidine.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem

Huang, Quan published the artcileTuning the dual emission of keto/enol forms of excited-state intramolecular proton transfer (ESIPT) emitters via intramolecular charge transfer (ICT), COA of Formula: C9H6BrNO, the publication is Dyes and Pigments (2021), 109497, database is CAplus.

Herein disclosed the adjustment of the dual emission of keto and enol forms of excited-state intramol. proton transfer (ESIPT) emitters via intramol. charge transfer (ICT) effects. Introducing electron-donating triphenylamine (TPA) and electron-withdrawing triphenylboron (TPB) substituents into the para-position of the phenolic hydroxyl group or the side of the oxazole of 2-(2′-hydroxyphenyl)oxazole skeleton endows the resulting compounds (6a-6d) with different photophys. properties. Owing to the ICT effect from electronic donor to acceptor, introducing TPA into the side of oxazole and TPB into the para-position of phenolic hydroxyl is conducive to an enol-form emission (6a). Exchanging the 2 substituents, introducing TPB into the side of oxazole and TPA into the para-position of phenolic hydroxyl, would be beneficial to a keto-form emission (6b). Synchronously introducing 2 identical substituents, whether TPA or TPB, into 2 sides of 2-(2′-hydroxyphenyl)oxazole skeleton (6c and 6d) would lead to the dual emission of keto and enol forms due to the excited-state equilibrium of ESIPT reactions, which are further verified by DFT calculation The organic light-emitting diode (OLED) devices with 6a and 6c as emitters were fabricated, both of which exhibit hybridized local and charge transfer (HLCT) excited-state characters with high external quantum efficiencies (EQEs) of 4.9% and 5.6%, resp.

Dyes and Pigments published new progress about 72571-06-3. 72571-06-3 belongs to oxazolidine, auxiliary class Oxazole,Bromide,Benzene, name is 5-(4-Bromophenyl)oxazole, and the molecular formula is C9H6BrNO, COA of Formula: C9H6BrNO.

Referemce:
https://en.wikipedia.org/wiki/Oxazolidine,
Oxazolidine | C3H7NO – PubChem