• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.985-990
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• 2000

${\zeta}-Carotene$ was subjected to ozonolysis in ice-cold dichloromethane. The ozonolysis products were fractionated with a silica column and the carbonyl fraction was analyzed by ODS-HPLC with a photodiode array detector. ${\zeta}-Carotene$ was solubilized in toluene, and then oxidized by incubating at $37^{\circ}C$, 72 hr under atmospheric oxygen. Carbonyl compound and acidic compound were produced. In comparison with autoxidation and ozonolysis, each compound showed the same retention time and UV-vis spectra were identical to the reference cleavage products prepared by ozonolysis of ${\zeta}-carotene$. Absorption spectrum of acidic compound was similar to that of standard 4,5-didehydrogeranyl geranyl acid which is known to possess biological activity. Thus, eccentric cleavage of ${\zeta}-carotene$ was confirmed to occur in vitro under oxidation condition.

• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.763-767
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• 2019

In this study, thermal decomposition characteristics of exo-tetrahydrodicyclopentadiene (exo-THDCP) composed with a single compound were analyzed by using a flow reactor. The experiments were carried out at $500^{\circ}C$, 50 bar and the products of each flow rate condition were analyzed by using a GC/MS. As a result, it was confirmed that exo-THDCP was decomposed mainly into cyclic compounds and a part was isomerized by heat. As the flow rate was increased, the kinds and ratio of compounds produced through the decomposition and isomerization were decreased. Also, the conversion rate of exo-THDCP and the amount of heat absorbed during the decomposition were also decreased. The compounds rapidly produced by decomposition were mainly formed through the radical form of 1-cyclopentylcyclopentene (1-CPCP) which is one of the intermediates that can be formed from exo-THDCP because it has the lowest activation energy of 42 kcal/mol.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1437-1441
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• 2000

Acycloretinoic acid was prepared from acycloretinal by oxidation with Tollens reagent. Acycloretinoic acid was separated with Silica-HPLC and analyzed by ODS-HPLC with a photodiode array detector and by GC-MS. Lycopene was solubilized in toluene and aqueous Tween 40, and then oxidized by incubating at $37^{\circ}C$ under atmospheric oxygen. Acidic compound was produced by autoxidation of lycopene. Retention time, UV-Vis spectra and mass spectra of the acidic compound were identical to the standard acycloretinoic acid. Thus, acycloretinoic acid was confirmed to occur in vitro under oxidation condition of lycopene.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.32-32
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• 2003

Calcuim borate 화합물의 하나인 Colemanite 천연원광을 출발물질로 붕산을 제조하는 공정에 대한 연구로 황산 첨가량과 처리온도, 건조온도와 시간에 따라 생성되는 붕산의 결정상과 수득률, 순도 및 입자의 형상을 관찰하였다. 황산 첨가로 붕소 성분은 용해되어 액상에 남고, SO$_4$$^{2-}$ 와 결합하여 불용성 고체로 분리되고, 붕소의 온도에 따른 용해도 차를 이용하여 재결정화하는 방법으로 99% 이상의 순도를 갖는 붕산(H$_3$BO$_3$)을 얻었다. 공정의 각 단계에서 생성되는 화합물을 TG, NMR, IR, XRD, ICP 등의 방법으로 분석하여 최적 제조 조건을 찾았다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.49-51
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• 2000

오존은 온도가 높고 태양 빛이 강한 여름철에 휘발성 유기화합물(Volatile Organic Compounds)과 질소화합물(NOx)의 광 화학 반응으로 생성되는 이차적 공해물질(Secondary Air Pollutant)이다. 성층권에 존재하는 오존은 피부암을 유발시키는 강한 자외선을 차단하고 흡수하는 고마운 존재이지만, 급속한 산업발달로 다량의 공해물질유출로 인해 생성된 지표면상의 오존은 대단히 유독해서 높은 농도에서 장시간 호흡 시 호흡기관의 장애는 물론이고 치사까지 이르게 하는 것으로 알려져 있다. (중략)

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.1-9
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• 2013

The transformation of alkylaromatic hydrocarbons using zeolite catalysts play big part in the current petrochemical industry. Here we review recent advances in the understanding of the reaction mechanisms of various alkylaromatic conversions with respect to the structural and physicochemical properties of zeolite catalysts employed. Indeed, the shape-selective nature of zeolite catalysts determines the type of reaction intermediates and hence the prevailing reaction mechanism together with the product distribution. The prospect of zeolite catalysis in the developement of more efficient petrochemical processes is also described.

• Journal of Hydrogen and New Energy
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• v.8 no.3
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• pp.131-135
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• 1997

Aromatic primary amines were prepared by the catalytic hydrogenation of aromatic nitro compounds in a benzene solution over 50 mg of 10 % palladium on charcoal at a room temperature under 45 psi. This paper describes a study on the catalytic hydrogenation of nitrobenzene-$d_5$, $^{15}N$-labelled nitrobenzene, and 4'-nitrobenzo-15-crown-5, respectively. The infrared absorption spectra exhibited a characteristic N-H stretching vibrations at 3450 and $3350cm^{-1}$. The results suggest that the non-readily available aromatic amines would be commercially produced by catalytic hydrogenation because of its good yield and little by-product formation.

• Food Science of Animal Resources
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• v.26 no.4
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• pp.441-446
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• 2006

The objective of this study was to investigate volatile compounds extracted from fresh pork belly during storage time at 4 or $20^{\circ}C$. Approximately thirty-one volatile compounds includingaromatics (6), aldehydes (6), acids (5), alcohols (4), ketones (4), alkanes (4), alkenes (1) and amines (1) in fresh pork belly were identified. Among them, volatile compounds such as 1-butanol, propane, 2-butanol, 3-hydroxy-2-butanone, acetic acid, 3-methyl-1-butanol, 1-pentanol, phenol, 2-pentyl-furan, indole and 2-dodecanone correlated with storage temperature and storage time. Aldehydes including hexanal and hexadecanal at 4t were the predominant volatile compounds, whereas at $20^{\circ}C$ storage, aromatics including phenol and indole, and alcohols including 2-butanol and 1-butanol were the predominant volatile compounds. Contents of 1-butanol, 2-butanol, 3-hydroxy-2-butanone, acetic acid, phenol and indole increased markedly with increased storage time, and 1-butanol, 2-butanol, 3-hydroxy-2-butanone, acetic acid, indole and 2-dodecanone were only detected at $20^{\circ}C$ storage.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.119-124
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• 1988

The desmutagenic effects of ${\alpha}$-hydroxycarbonyl compounds, such as glyceraldehyde, glycolaldehyde, dihydroxyacetone, furfural, 5-hydroxymethylfurfural, maltol, acetol and acetoin and ${\alpha}$-dicarbonyls, such as diacetyl, glyoxal, methyl glyoxal and 2, 3-pentanedione were investigated against the mutagenic heterocyclic amines, such as Trp-P-1, Trp-P-2, Glu-P-1, Glu-P-2 and IQ. Most of the carbonyl compounds suppressed the mutagenicity of heterocyclic amines for S. typhimurium TA98, ${\alpha}$-dicarbonyl compounds showing a higher desmutagenic effect than ${\alpha}$-hydroxycarbonyl compounds. Among the ${\alpha}$-hydroxycarbonyl compounds, glyceraldehyde, glycolaldehyde and dihy-droxyacetone showed more effective desmutagenicity, and diacetyl among the ${\alpha}$-dicabonyl compounds had the highest desmutagenic effect. These carbonyl compounds alone also showed mutagenicity to S. typhimurium TA100 without S-9 mix. The reaction of carbonyl compounds with mutagenic heterocyclic amines also eliminated the mutagenicity of the former for S. typhimurium TA100.

• Journal of the Korean Chemical Society
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• v.24 no.5
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• pp.393-397
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• 1980

Trimethylstannyl-diethylamine, trimethylstannylethylsulfide, trimethylstannylmethoxide and trimethylstannylhydroxide were reacted with phenylisocyanate at various temperatures. The product was only triphenylisocyanurate below $100^{\circ}C$ and the mixtures of triphenylisocyanurate and diphenylcarbodiimide were obtained at $150^{\circ}C$. Whereas, in the reaction of trimethylstannyldiethylamine with chloral, N,N-diethylformamide and trimethylstannyltrichloromethide were produced. The products from the reaction of N-ethylhexamethyldistannazane with phenylisothiocyanate were bis(trimethylstannyl) sulfide and N-ethyl-N'-phenylcarbodiimide.