28588-74-1Relevant articles and documents
Novel Taste-Enhancing 4-Amino-2-methyl-5-heteroalkypyrimidines Formed from Thiamine by Maillard-Type Reactions
Brehm, Laura,Frank, Oliver,Jünger, Manon,Wimmer, Miriam,Ranner, Josef,Hofmann, Thomas
, p. 13986 - 13997 (2019/12/27)
Increasing the thiamine concentration in a respective process flavor yields a product with a significant higher kokumi activity. S-plot analysis of the mass spectrometric data revealed beside thiamine itself, 4-methyl-5-thiazoleethanol, (S)-((4-amino-2-methylpyrimidin-5-yl)methyl)-l-cysteine, N-((4-amino-2-methylpyrimidin-5-yl)methyl)formamide, 3-(((4-amino-2-methylpyrimidin-5-yl)methyl)thio)-5-hydroxypentan-2-one, and 2-methyl-5-(((2-methylfuran-3-yl)thio)methyl)pyrimidin-4-amine as marker molecules for a process flavor with higher thiamine concentration. Sensory-based targeted isolation revealed that (S)-((4-amino-2-methylpyrimidin-5-yl)methyl)-l-cysteine, 3-(((4-amino-2-methylpyrimidin-5-yl)methyl)thio)-5-hydroxypentan-2-one, and 2-methyl-5-(((2-methylfuran-3-yl)thio)methyl)pyrimidin-4-amine showed an influence on the kokumi taste activity with taste threshold concentrations between 35 and 120 μmol/L. An adapted mass spectrometric-based carbon module labeling experiment as well as quantitative studies clearly demonstrated thiamine as the only precursor and an intermolecular formation pathway for the compounds (S)-(((4-amino-2-methylpyrimidin-5-yl)methyl)thio)-5-hydroxypentan-2-one and 2-methyl-5-(((2-methylfuran-3-yl)thio)methyl)pyrimidin-4-amine. On the basis of the knowledge that several thiamine derivatives showed taste-modulating activity, selected thiamine-based binary model reactions and synthesis were carried out. This resulted in the isolation of further thiamine-derived taste modulators like (S)-((4-amino-2-methylpyrimidin-5-yl)methyl)-l-cysteinylglycine, (S)-3-((((4-amino-2-methylpyrimidin-5-yl)methyl)thio)methyl)piperazine-2,5-dione, 3-(((4-amino-2-methylpyrimidin-5-yl)methyl)thio)pentan-2-one, 5-(((furan-2-ylmethyl)thio)methyl)-2-methylpyrimidin-4-amine, and (4-amino-2-methylpyrimidin-5-yl)methanethiol, 2-methyl-5-((methylthio)methyl)pyrimidin-4-amine with taste thresholds ranging from 35 to 880 μmol/L.
Method for preparing 2-methyl-3-sulfydryl furan
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Paragraph 0042; 0043; 0051; 0052; 0058; 0059; 0064; 0065, (2017/07/21)
The invention relates to a method for preparing 2-methyl-3-sulfydryl furan. The method comprises the following steps: mixing methanol, sodium carbonate and 2-methyl furan, introducing chlorine gas under a low temperature condition, performing solid-liquid separation and taking liquid for distillation, so as to obtain a product 1; washing the product 1 with water, dropwise adding thioacetic acid, and performing extraction and phase separation after adding, so as to obtain a product 2; adding the product 2 into a dehydrating agent for dehydration, standing for phase separation, dropwise adding an obtained product into sodium hydroxide solution for reaction, stirring the mixture, standing for phase separation, taking an organic phase for distillation and purifying by rectification, so as to obtain 2-methyl-3-sulfydryl furan. Compared with the existing preparation method, the method for preparing 2-methyl-3-sulfydryl furan, disclosed by the invention, has the advantages that reaction conditions are controlled easily, side reactions are less, intermediate products are controlled easily, the yield of a target product is as higher as about 85%, and the method has wide application prospect.
Investigation of the aroma-active compounds formed in the maillard reaction between glutathione and reducing sugars
Lee, Sang Mi,Jo, Ye-Jin,Kim, Young-Suk
experimental part, p. 3116 - 3124 (2011/08/05)
Aroma-active compounds formed during the thermal reaction between glutathione (GSH) and reducing sugars were analyzed by gas chromatography-mass spectrometry (GC-MS) and GC-olfactometry (GC-O) with aroma extract dilution analysis (AEDA). Application of AEDA to glutathione Maillard reaction products (GSH MRPs) led to the identification of 19 aroma-active compounds in the thermal reaction of glutathione with glucose or fructose. In addition, the carbohydrate module labeling (CAMOLA) approach was also employed to elucidate the formation pathways for selected target sulfur aroma compounds, such as 5-methylthiophene-2-carbaldehyde and 3-methylthiophene-2-carbaldehyde, which have not been reported previously. The intact carbon skeleton of glucose via 3-deoxyhexosone is incorporated into 5-methylthiophene-2-carbaldehyde with the hydrogen sulfide of GSH. On the other hand, the formation of 3-methylthiophene2-carbaldehyde may occur via the recombination of a C-4 sugar fragment and mercaptoacetaldehyde.
Determination and isolation of a thioesterase from passion fruit (Passiflora edulis Sims) that hydrolyzes volatile thioesters
Tapp, Edward J.,Cummins, Ian,Brassington, David,Edwards, Robert
experimental part, p. 6623 - 6630 (2010/04/06)
Volatile organosulfur compounds (VOSCs) are high impact aroma chemicals characteristic of tropical fruits which are active as both free thiols and the respective thioesters. Using a simple and sensitive colorimetric enzyme assay, a thioesterase activity toward VOSCs has been identified in ripening purple passion fruit (Passiflora edulis Sims). The assay was based on determining the release of free thiols from 2-methyl-3-furanthiol acetate using Ellman's reagent. The major thioesterase in the fruit was found to be a wall-bound protein in the mesocarp. The extracted enzyme activity was purified 150-fold and shown to be associated with a 43 kDa monomeric serine hydrolase which was selectively labeled with a fluorophosphonate suicide probe. MS-MS sequencing identified the thioesterase as a class 13 glycoside hydrolase, most similar to pectin acetylesterase, an enzyme involved in cell wall modifications in the peel of a number of fruit. Our results suggest that cell wall hydrolases in tropical fruit may have additional useful roles in biotransforming VOSCs.
Effect of pH on the maillard reaction of [C]xylose, cystein, and thiamin
Cerny, Christoph,Briffod, Matthieu
scheme or table, p. 1552 - 1556 (2009/10/01)
The influence of different pH values, ranging from 4.0 to 7.0, on the formation of sulfur volatiles in the Maillard reaction was studied using a model system with [13C5]xylose, cysteine, and thiamin. The use of 13C-labeled xylose allowed, by analysis of the mass spectra, volatiles that incorporated xylose carbons in the molecule from other carbon sources to be discerned. For 2-furaldehyde and 2-furfurylthiol, which were favored at low pH, the labeling experiments clearly indicated that xylose was the exclusive carbon source. On the other hand, xylose was virtually not involved in the formation of 3-mercapto-2-butanone, 4,5-dihydro-2-methyl-3- furanthiol, and 5-(2-hydroxyethyl)-4-methylthiazole, which apparently stemmed from thiamin degradation. Both xylose and thiamin seemed to significantly contribute to the formation of 2-methyl-3-furanthiol, 3-mercapto-2-pentanone, and 2-mercapto-3-pentanone, and therefore different formation pathways must exist for each of these molecules. In general, the pH determined strongly which volatiles were formed, and to what extent. However, the relative contribution of xylose to the C-skeleton of a particular compound changed only slightly within the investigated pH range, when both xylose and thiamin were involved in the formation.
Formation of aroma compounds from ribose and cysteine during the Maillard reaction
Cerny, Christoph,Davidek, Tomas
, p. 2714 - 2721 (2007/10/03)
The headspace volatiles produced from a phosphate-buffered solution (pH 5) of cysteine and a 1 + 1 mixture of ribose and [13C5]ribose, heated at 95 °C for 4 h, were examined by headspace SPME in combination with GC-MS. MS data indicated that fragmentation of ribose did not play a significant role in the formation of the sulfur aroma compounds 2-methyl-3-furanthiol, 2-furfurylthiol, and 3-mercapto-2-pentanone in which the carbon skeleton of ribose remained intact. The methylfuran moiety of 2-methyl-3-(methylthio)furan originated from ribose, whereas the methylthio carbon atoms came partly from ribose and partly from cysteine. In 3-mercapto-2-butanone one carbon unit was split from the ribose chain. On the other hand, all carbon atoms in 3-thiophenethiol stemmed from cysteine. In another trial cysteine, 4-hydroxy-5-methyl-3(2H)-furanone and [13C5]ribose were reacted under the same conditions. The resulting 2-methyl-3-furanthiol was mainly 13C5-labeled, suggesting that it stems from ribose and that 4-hydroxy-5-methyl-3(2H)-furanone is unimportant as an intermediate. Whereas 2-mercapto-3-pentanone was found unlabeled and hence originated from 4-hydroxy-5-methyl-3(2H)-furanone, its isomer 3-mercapto-2-pentanone was formed from both 4-hydroxy-5-methyl-3(2H)-furanone and ribose. A new reaction pathway from ribose via its 1,4-dideoxyosone is proposed, which explains both the formation of 2-methyl-3-furanthiol without 4-hydroxy-5-methyl-3(2H)-furanone as an intermediate and a new way to form 3-mercapto-2-pentanone.
Quantitative Model Studies on the Effectiveness of Different Precursor Systems in the Formation of the Intense Food Odorants 2-Furfurylthiol and 2-Methyl-3-furanthiol
Hofmann,Schieberle
, p. 235 - 241 (2007/10/03)
The yields of the two intense food odorants 2-furfurylthiol (FFT) and 2-methyl-3-furanthiol (MFT) obtained by heating mixtures of possible precursors in model systems varying in temperature, pH value, or water content were determined by using stable isotope dilution assays. Although pentoses generated much higher amounts of FFT and MFT than hexoses when heated in the presence of cysteine, glucose and rhamnose also gave significant yields. Studies on several intermediates indicated the highest yields for MFT (1.4 mol %) when hydroxyacetaldehyde and mercapto-2-propanone were reacted for 6 min at 180 °C in the absence of water. Both intermediates also generated significant amounts of FFT (0.05 mol %). However, the system furan-2-aldehyde/H2S showed a 10 times higher efficiency in generating FFT. Thiamin and norfuraneol/cysteine were less effective precursors of MFT. The results imply that different formation pathways may run in parallel during food processing and may account for the different amounts of the two odorants present in the respective food.
Process for the manufacture of furan derivatives
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, (2008/06/13)
The invention is concerned with a process for the manufacture of substituted furans which are, in particular, flavorants; thereby 4-hydroxy-2-yn-1-ones or acetals or ketals thereof are cyclized with nucleophilic S-compounds to 3-S-furans, whereby this 3-S atom can be optionally substituted, and the acetylene derivatives, the 4-hydroxy-2-yn-1-ones, can be optionally 1- and/or 4-alkyl or alkenyl substituted.
Certain 3-furyl sulfides
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, (2008/06/13)
Novel 3-sulfur derivatives of furan including alkyl furan-3-thiols and bis(alkyl-3-furyl) sulfides and di- and tetrahydro derivatives thereof having meaty and/or roasted aromas and flavors; processes for producing such 3-sulfur derivatives; novel flavoring compositions containing such derivatives; and novel food compositions containing such derivatives.
