13623-11-5Relevant articles and documents
Use of a metallation reaction to obtain substituted 2-(5-methyl-2- thiazolyl)ethanols
Liakina,Formanovsky,Popova,Mikhura
, p. 877 - 882 (2005)
The interaction of anions, obtained by treating 2,4,5-trimethylthiazole and 2,5-dimethyl-4-phenylthiazole with butyllithium, with aliphatic and aromatic aldehydes leads to substituted 2-thiazolyl-1-ethanols. It was established that the metallation reaction occurs at the 2-methyl group of the thiazoles. 2005 Springer Science+Business Media, Inc.
Mechanism of formation of sulphur aroma compounds from l-ascorbic acid and l-cysteine during the Maillard reaction
Yu, Ai-Nong,Tan, Zhi-Wei,Wang, Fa-Song
, p. 1316 - 1323 (2012)
The sulphur aroma compounds produced from a phosphate-buffered solution (pH 8) of l-cysteine and l-, l-[1-13C] or l-[4-13C] ascorbic acid, heated at 140 ± 2 °C for 2 h, were examined by headspace SPME in combination with GC-MS. MS data indicated that C-1 of l-ascorbic acid was not involved in the formation of sulphur aroma compounds. The sulphur aroma compounds formed by reaction of l-ascorbic acid with l-cysteine mainly contained thiophenes, thiazoles and sulphur-containing alicyclic compounds. Among these compounds, 1-butanethiol, diethyl disulphide, 5-ethyl-2-methylthiazole, cis and trans-3,5-dimethyl-1,2,4-trithiolane, thieno[2,3-b]thiophene, thieno[3,2-b]thiophene, cis and trans-3,5-diethyl-1,2,4-trithiolane, 1,2,5,6-tetrathiocane, 2-ethylthieno[2,3-b]thiophene, 2,4,6-trimethyl-1,3,5- trithiane and cyclic octaatomic sulphur (S8) were formed solely by l-cysteine degradation, and the rest by reaction of l-ascorbic acid degradation products, such as hydroxybutanedione, butanedione, acetaldehyde, acetol, pyruvaldehyde and formaldehyde with l-cysteine or its degradation products, such as H2S and NH3. A new reaction pathway from l-ascorbic acid via its degradation products was proposed.
Thiazole, imidazole and oxazole compounds and treatments of disorders associated with protein aging
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, (2008/06/13)
Provided are, among other things, compounds of formula I or IA, . Also provided are methods of treatment with such compounds.
Method for treating glaucoma IIB
-
, (2008/06/13)
Provided is a method of decreasing intraocular pressure or improving ocular accommodation in an animal, including a human, comprising administering an intraocular pressure decreasing amount or ocular accommodation improving amount of a compound of the formula I or IA, wherein J is oxygen, sulfur, or N—Rd.
Characterization of volatile compounds from the reaction of 3-hydroxy- 2-butanone and ammonium sulfide model system
Xi, Junwu,Huang, Tzou-Chi,Ho, Chi-Tang
, p. 245 - 248 (2007/10/03)
The reactions between 3-hydroxy-2-butanone and ammoniun sulfide at 25, 50, 75, 100, 125, and 150 °C were studied. Four well-known flavor compounds, 2,4,5-trimethyloxazole, 2,4,5-trimethyl-3-oxazoline, 2,4,5-trimethylthiazole, and 2,4,5-trimethyl-3-thiazoline, were identified. Another four interesting intermediate compounds, 2-(1-hydroxyethyl)-2,4,5-trimethyl-3-oxazoline, 2- (1-mercaptoethyl)-2,4,5-trimethyl-3-oxazoline, 2-(1-hydroxyethyl)-2,4,5- trimethyl-3-thiazoline, and 2-(1-mercaptoethyl)-2,4,5-trimethyl-3-thiazoline, were also identified by GC-EIMS and GC-CIMS. All these intermediate compounds were formed at 25 °C. On the other hand, tetramethylpyrazine was the major product with a reaction temperature higher than 100 °C.
Maillard-Lipid Interactions in Nonaqueous Systems: Volatiles from the Reaction of Cysteine and Ribose with Phosphatidylcholine
Mottram, Donald S.,Whitfield, Frank B.
, p. 1302 - 1306 (2007/10/02)
Equimolar mixtures of cysteine and ribose mixed with an excess of microcrystalline cellulose powder were heated at 185 deg C with or without the addition of phosphatidylcholine.Volatile products were analyzed by headspace concentration and GC-MS.Sulfur-containing heterocyclic compounds dominated the volatiles, with trithiolanes, trithianes, and thiazoles among the most abundant components.Some qualitative and quantitative differences were found between the volatiles from the reactions performed with and without cellulose.The cellulose was not totally inert; volatiles were formed from its thermal degradation and its reaction with cysteine.In general, the addition of phospholipid had only a small effect on the volatile profile, with small amounts of lipid degradation products and lipid-Maillard interaction products formed.However, three methylthio-substituted furans and thiophenes were found in the phospholipid-containing systems which were not detected in the lipid-free reaction mixtures.Keywords: Maillard reaction; aroma; volatiles; cysteine; ribose; phospholipid
Reactivity of Heterocyclic Nitrogen Donors in Systems containing the Tetrachloroaurate(III) Anion
Canovese, Luciano,Cattalini, Lucio,Tomaselli, Michele,Tobe, Martin L.
, p. 307 - 314 (2007/10/02)
A series of gold(III) complexes of the type has been prepared and characterized (L = oxazole, benzoxazole, thiazole, their benzo and methyl-substituted derivatives, or 2-methylbenzoselenazole).The five-membered N.O-, N,S- and N,Se-heterocyclic bases are all bound to Au(III) through nitrogen.The kinetics of the displacement of L by chloride to give (1-) has been studied in methanol-water (95:5. v/v) at 25.0 deg C and I = 0.20 mol dm-3 (LiClO4).The equilibrium constants for the reversible processes have also been determined.The reactions of the corresponding pyridine, 4-chloro-, 4-cyano- and 2,6-bis(chloromethyl)-pyridine complexes have also been reexamined under the same conditions.The equlibrium constants, K2, depend upon the basicity of the nitrogen in the ligands and points for all ligands, irrespective of ring size and composition, lie roughly on the same log K2 versus pKa curve.There is no significant systematic steric effect on the equilibrium constants of the sort found for the more basic methyl pyridines.The complexes of the five-membered heterocyclic ligands are approximately ten times less reactive than those of the six-membered N-heterocycles of comparable basicity and exhibit steric retardation from ortho-methyl substituents.The nucleophilicities of these ligands have been calculated and five-membered N,O- and N,S-heterocycles are considerably less reactive than six-membered N-heterocycles of similar basicity.
