• Bulletin of the Korean Chemical Society
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• v.11 no.1
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• pp.22-25
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• 1990

The condensation of 1-amino-1,2-dihydro-3,6-pyridazinedione (1) and 2-amino-2,3-dihydro-1,4-phthalazinedione (2) with mesityl oxide or 3-penten-2-one in acetic acid-ethanol (1:1) gave 3,4,6,9-tetrahydro-6,9-dioxopyridazino[1,2-a][1,2, 3]triazines (9,11) and 3,4,6,11-tetrahydro-6,11-dioxo[1,2,3]triazino[1,2- b]phthalazines (10,12), respectively. The condensation of 1 and 2 with crotonaldehyde, cinnamaldehyde or acrylaldehyde under the same reaction condition gave only N-alkylidene derivatlives (3-8). When the N-alkylidene derivatives isolated from the reaction of 1 and 2 with crotonaldehyde and cinnamaldehyde (3-6) were refluxed in acetic acid, the corresponding heterocyclic compounds (13-16) were obtained.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.1
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• pp.45-51
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• 1986

Equimolar aqueous solutions of D-glucose and glycine were heated at $50^{\circ}C\;and\;95^{\circ}C$ at pH 6.7. The headspace volatiles and the ether extracts from the reaction mixture were analyzed by gas chromatography and gas chromatography-mass spectrometry using a fused silica capillary column. The major components formed were identified as diacetyl, three furfurals, two pyrroles, one furanone, two pyranones and two amides. In order to elucidate the formation mechanisms of the amides formed front amino-carbonyl reaction, two model systems were adopted. N-butylacetamide were formed as major components from diacetyl-butylamine ana glyoxal-butylamine systems, respectively. The results obtained suggest that such ${\alpha}-dicarbonyls$ as 3-deoxy-D-erythro-2,3-hexodiulose and diacetyl generated in the amino-carbonyl reaction react with amino compounds, amides then being formed by cleavage of the C-C bond in the ${\alpha}-dicarbonyls$.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.351-359
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• 1989

This study was conducted to observe the physico-chemical exchange and effect of amino-carbonyl reaction between fructose and glycine . When various buffer solutions were added to equimolar mixture of fructose and glycine at pH 6.0 and $100^{\circ}C$, the browning effect was markedly observed by Mcllvaine buffer. Among the combinations of temperature and reaction time, the deep browning effect was obtained above $100^{\circ}C$, 3hr A marked browning effect obtained above pH 7.0 but little observed below pH 7.0. The browning effect was markedly increased at high fructose concentration. It required 4.0hrs and 32.9hrs to decrease 50% of initial concentration of fructose and glycine at $100^{\circ}C$ and pH 7 but 0.9hrs and 3.8hrs at $120^{\circ}C$, pH 7.0, respectively. The rate constant of fructose and glycine at $100^{\circ}C\;and\;120^{\circ}C$ were $1.78{\times}10^{-1},\;2.11{\times}10^{-2}\;and\;7.74{\times}10^{-1},\;1.83{\times}10^{-1}$, respectively. The formation of HMF was likely to follow the first order kinetics. The addition of 0.1M sodium sulfite, 0.1M sodium bisulfite and 0.1M calcium chloride to equimolar mixture (0.05M) surpressed the reaction up to 76.8%, 76.8% and 96.4%, respectively.

• Clean Technology
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• v.29 no.2
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• pp.79-86
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• 2023

The homogeneous catalyst, Ru-MACHO-BH, selectively performs hydrogenation reactions only on the carbonyl group of α, β-unsaturated aldehyde compounds with extremely high reactivity and selectivity. However, the hydrogenation of α, β-unsaturated aldehydes involves a heterogeneous Diels-Alder reaction, resulting in the formation of significant amounts of byproducts, such as dimers. In this study, we used the Ru-MACHO-BH catalyst (Carbonyl hydrido (tetrahydroborato) [bis (2-diphenyl phosphino ethyl) amino] ruthenium(II)) to selectively hydrogenate the carbonyl group of a specific type of α, β-unsaturated aldehyde called methacryl aldehyde, leading to the synthesis of methallyl alcohol. Simultaneously, we applied diols to inhibit the formation of byproducts. The results demonstrate that monoethylene glycol can significantly reduce the formation of diols. Based on these results, we effectively suppressed the formation of dimers containing vinyl groups in methacryl aldehyde by using hydroquinone, which can efficiently inhibit the chemical interaction of vinyl groups. Consequently, the conversion rate of methacryl aldehyde was increased. Ultimately, by reducing the amount of the expensive homogeneous catalyst Ru-MACHO-BH to 1/10, we achieved a selectivity of over 90% and a yield of over 80% for the desired product, methallyl alcohol. These results provide a method to minimize yield reduction while reducing the usage of expensive catalysts, thereby improving cost-effectiveness. We expect that the reaction could be applied to various kinds of selective hydrogenation and has been successfully run on an industrial scale.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.234.2-235
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• 2002

An efficient method for the simultaneous profiling analysis of organic acids and amino acids combined with a simple graphic pattern recognition method was developed for more objective diagnosis of organic acidurias and amino acidurias. In this method, extractive ethoxycarbonly (EOC) reaction of amino and sufhydry groups with ethyl chloroformate was followed by methodime (MO) formation of carbonyl group in aqueous solution (omitted)

• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.1
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• pp.51-56
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• 1982

The thermal degradation of 0.05M glucose-arginine model system was occurred during heat treatment for 0$\sim$7 hours at $60{\sim}120^{\circ}C$. and the melanoid in formation was investigated as a function of temperature. The decomposition reaction of glucose and arginine, as well as the reaction of melanoidin formation, followed first-order kinetics, except the reaction at $120^{\circ}C$. and the rate constants ($hr^{-1}\times 10^3$) of those reactions were ranged from 14.20 to 837. 10. Temperature dependence of the rate constants was characterized by the Arrhenius equation, except the reaction at $120^{\circ}C$. The ranges of activation energy and $Q_{10}$ values were 12.122$\sim$18.142 kcal/mole and 1.65$\sim$2.12, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.9
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• pp.1182-1187
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• 2007

Changes in composition of fatty acids and free amino acids in three differently dried Alaska pollack (sun dried, naturally cyclic freeze-thaw dried, and 1-year-aged cyclic freeze-thaw dried Alaska pollack (Hwangtae)) were investigated to correlate them with browning reactions in drying and aging Alaska pollack. Major fatty acids of the sun dried Alaska pollack were palmitic acid, oleic acid, and eicosapentaenoic acid (EPA), and those in the Hwangtae were palmitic acid, oleic acid, and gondoic acid. Hwangtae showed the lowest amount of polyunsaturated fatty acids among the three types of dried Alaska pollack. Free amino acids content of sun dried Alaska pollack was higher than that of the cyclic freeze-thaw dried Alaska pollack and Hwangtae. Lesser amount of histidine in Hwangtae (0.02%) than that in the cyclic freeze-thaw dried Alaska pollack (0.087%) may indicate the degradation of histidine due to the browning reaction in aging the cyclic freeze-thaw dried Alaska pollack. Significant changes in compositions of fatty acids and free amino acids among the dried products revealed the browning reaction resulted from carbonyl compounds produced by decomposition of lipid hydroperoxides and free amino acids. Aging the cyclic freeze-thaw dried Alaska pollack for a year contributed to the development of browning.

• Journal of Ginseng Research
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• v.30 no.1
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• pp.41-48
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• 2006

In the browning reaction of Korean ginseng, it appears that enzymatic and non-enzymatic browning reaction occurred In initial stage of steaming fresh ginseng at low temperature, and then non-enzymatic browning reaction followed in the drying period after steaming. Browning reaction of red ginseng occurred between $60{\sim}90$ min of steaming at $100^{\circ}C$, and browning pigments of red ginseng were mostly water soluble substances. The structural characteristics of water soluble browning reaction products(WS-BRPs) isolated from Korean red ginseng were showed the presence of hydroxyl, amide carbonyl and aliphatic methane groups. From sugar analysis it was identified that L and S-1, melanoidins isolated from red ginseng, contained two kinds of sugars, glucose and xylose, and the other melanoidin S-2 contained the previous and fructose. In order to find out pertinent methods for the acceleration of browning during ginseng processing, various treatment were made on fresh ginseng with sugars, amino acids and inorganic nitrogenous compounds and the extent of browning was measured. Among sugar tested, maltose resulted in the greatest acceleration of browning followed in decreasing order by glucose and lactose, whereas pentoses, fructose, sucrose and raffinose had negligible effect. A marked browning occurred in ginseng treated with basic amino acids, while the extent of browning was not greatly increased when ginseng was treated with aliphatic amino acids, hydroxyl amino acids, or acidic amino acids. The brown color intensity gradually increased with an increase of glucose concentration far up to 0.5M. L, S-1, and S-2 were found to have an ability to donate hydrogen to DPPH, and also they had anti-oxidative activity in the experiments of hydrogen peroxide scavenging, inhibitory activity in the formation of MDA from linoleic acid, auto oxidation of ok-brain homogenates, lipid peroxidation by the enzymatic and non-enzymatic system in liver microsome fraction, and mitochondrial fraction etc. The amounts of acidic polysaccharide(AP) in red ginseng were higher than those of wild and cultured Panax quinquefolius, Panax notoginseng as well as white ginseng (Panax ginseng). In white ginseng, the AP amount is no difference in root ages or sizes, also, the AP amount of ginseng body was similar to that of rhizome, but was higher than that of leaf and epidermis. Addition of red ginseng acidic polysaccharide(RGAP) increased production of nitric oxide(NO) and tumor necrosis factor (TNF)-$\alpha$ in the rodent macrophage cultures, and treatment of RGAP in vivo stimulated tumoricidal activities of natural killer (NK) cells.

• Journal of the Korean Chemical Society
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• v.33 no.4
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• pp.426-430
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• 1989

Amino alcohol-derived thiazolidinethiones [4-(S)-IPTT, 4(S)-ETT] serve as efficient chiral auxiliary in tin medicated aldol condensation. A highly enantioselective aldol-type reaction forming various ${\beta}$-hydroxy carbonyl compounds from 3-acetylthiazolidine-2-thione and achiral aldehyde is achieved via divalent tin enolate. The other advantages of these chiral auxiliaries were the ease of removal by methanolysis.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.505.2-506
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• 1986

L-Azetidine-2-carboxylic acid (A-2-C), a four-membered cyclic imino acid has been identified in certain plants, and the microorganism Actinoplanes ferrugineus. The imino acid A-2-C has a physiological significance as an antgaonist of proline during peptide synthesis. The biosynthetic mechanism for the formation of A-2-C has not been studied in any detail. By using various amino acids such as methionine and S-adenosyl-L-methionine labeled with deuterium or carbon-14, the details of the biosynthetic pathway and a possible mechanism for the formation of L-A-2-C in .4. ferrugineus have been unravelled, Both in vivo and in vitro experimental results suggest the biosynthesis of L-A-2-C is mediated by a confactor containing a carbonyl group, probably pyridoxal Phosphate. S-Adenosyl-L-methionine, which seems to be the direct biosynthetic substrate, has undergone a f-displacement by an ${\alpha}$-amino group of the amino acid portion of the substrate S-adenosyl-L-methionine potentially via a vinylglycine intermediate. The overall stereochemical events at the ${\beta}$-carbon of the substrate have been shown to inversion of configuration. The overall stereochemical events at the -position of the sub- strate have also been shown to occur with inversion of configuration. The ${\beta}$, ${\gamma}$-elimination reaction of the substrate seems to follow a cisoidal-type mechanism and the addition portion of the reaction a transoidal-type mechanism . The assignment of the proton NMR of A-2-C has been deduced by apply- ing NOE difference experiments, Gd(III) line-broadening experiments and 2D-NOESY experiments of regio-and stereospecificially deuterated A-2-C's.