• Bulletin of the Korean Chemical Society
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• v.6 no.2
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• pp.103-107
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• 1985

Quantum chemical calculations were carried out to explain how the electronic states of some series compounds vary with metabolic activation. Compounds studied included aromatic amines and amides, polycyclic hydrocarbons, and a few alkylating agents that do not require metabolic activation. The 1, 2 and 4 positions forming the trans-butadiene frame of a molecule, henceforth referred to as "the trans 1, 2, 4 region", have seen to be important positions for the prediction of carcinogenic activity of these compounds. It is also evident that their electrophilic properties increase with metabolic activation. That is the sum of ${\pi}$-electron densities of the trans 1, 2, 4 region in the lowest unoccupied molecular orbital (LUMO) has been found to increase in the order of precarcinogens < proximate-ones < the carbocation ultimate-ones. This is consistent with the fact that chemical carcinogens become more strongly electrophilic with activating. This region not only provides a unified view of structurally diverse carcinogens, but also predicts uniformity in their reactive sites. Accordingly, we suggest that an understanding of the trans 1, 2, 4 region would be helpful in elucidating the mechanism of carcinogenesis.

• Bulletin of the Korean Chemical Society
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• v.2 no.1
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• pp.29-34
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• 1981

Chemical shift values of ${\alpha}$-proton of trans- and cis-methyl cinnamates are well correlated with ${\sigma}({\sigma}_1,\; {{\sigma}_R}^{\alpha})$, and (F, R) (r=0.999-0.879). It is observed that (1) the degree of variation of ${\delta}H_{\alpha}$ value by varying the substituents in trans-cinnamates is similar to that of cis-cinnamates $({\rho}_{trans}=0.296,\;{\rho}_{cis}=0.2840, (2) resonance contribution is larger in the trans-cinnamates than that in the cis-cinnamates, but inductive contribution is reversed, (3) for m-substitued derivatives, resonance contribution is very small compared to that for p-substituted derivatives.

• Bulletin of the Korean Chemical Society
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• v.13 no.1
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• pp.65-70
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• 1992

The hindered internal rotation effect of methyl group on chemical reaction was studied for cis-trans isomerization reaction of 1-bromopropene system using RRKM technique. A comparative study of the isomerization rates was also performed between the rigid and allowed internal rotations. The calculated rate of rigid cis-trans isomerization of 1-bromopropene was shown to be three times higher than its other halogenated propene homologues with its internal rotations and found to be in good agreement with experimental observations. These findings could be explained reasonably well in terms of the differences of the rotational barrier heights among halogenated propenes and correlated with the relatively low internal rotation barrier of cis-1-bromopropene, 230 cal/mol, compared to those of other cis-1-halopropenes, 700-800 cal/mol, and trans-1-halopropenes, 2.0-2.4 kcal/mol.

• Bulletin of the Korean Chemical Society
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• v.17 no.9
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• pp.786-790
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• 1996

A novel optically active tetraamine ligand possessing four asymmetric centers, N,N'-bis(2(S)-aminopropyl)-1(R),2(R)-trans-1,2-diaminocyclohexane (SRRS-apchxn) and its cobalt(Ⅲ) complexes, [Co(SRRS-apchxn)X2]n+ (X=Cl-, H2O, X2=CO32-) have been synthesized. This ligand has coordinated stereospecifically to the cobalt(Ⅲ) ion to give only the Λ-uns-cis-(SS) isomer. A trans dichloro complex has been obtained via the stereospecific isomerization of Λ-uns-cis-(SS)-[Co(SRRS-apchxn)Cl2]+ to trans-(SS)-[Co(SRRS-apchxn) Cl2]+ in CH3OH-HCl medium. Ligand and complexes have been characterized by electronic absorption, 1H NMR, CD spectra, and also by elemental analysis. It is of interest that this is one of the few CoⅢ(N4)X2 type complex preparations, which produces such an uns-cis isomer with stereospecificity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.6
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• pp.752-760
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• 2008

Scale-up production of low-trans fat containing conjugated linoleic acid (CLA-TFO) was performed through lipase-catalyzed synthesis. Blend of fully hydrogenated soybean oil, olive oil containing conjugated linoleic acid and palm oil with 1:2:7 ratio was interesterified through Lipozyme RM IM in the 1 L-batch type reactor at $65^{\circ}C$ for 12 hrs, and the physicochemical and melting properties of CLA-TFO were compared with conventional (high trans fat) or commercial low-trans fat shortening. The trans fatty acids content in the conventional shortening (48.8 area%) was much higher than that of low-trans shortening (0.4 area%) and CLA-TFO (0.3 area%+CLA; 7.6 area%). Acid, saponification and iodine values of CLA-TFO were 0.4, 173.9 and 59.0, respectively. Their ${\alpha}$-, ${\gamma}$-tocopherol contents showed 4.7, 1.0 mg/100 g. Differences were observed in the solid fat contents (SFC), melting point of the conventional or low-trans fat and CLA-TFO. Each SFC of conventional, low-trans fat and CLA-TFO was 32.0, 29.3 and 30.4% with melting point of 38.5, 43.0 and $39.5^{\circ}C$ at $35^{\circ}C$, respectively. In texture profile analysis, hardness of conventional, low-trans fat and CLA-TFO was 111.7, 75.2 and 63.8 g.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.1
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• pp.117-123
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• 2007

HPLC quantifications of fresh and cooked (steamed/microwaved) spinach, one of the most frequently consumed vegetables in foodservice operations, were carried out to determine carotenoids compositions. An S-3 $\mu$m C30 stationary phase for reversed-phase columns with diode-array detection was used to separate and quantify geometric isomers of provitamin A carotenoids in the fresh and cooked spinach. The carotenoids in fresh spinach were identified and quantified: Lutein (63.0%), $\beta$-carotene isomers (all-trans 29.6%, 9-cis 3.2%, 13-cis 1.8%, $\alpha$-carotene 0.4%, zeaxanthin 2.1%) and cryptoxanthin. Cryptoxanthin, detected in a trace amount in HPLC, was not quantified in this study. Lutein was little affected by cooking methods and frozen conditions. 9-cis and 13-cis-$\beta$-carotene isomers were major types formed during cooking. Cooking (steam/microwave) did not alter carotenoid profiles of the samples, but the amounts of carotenoids quantified were greater than those in the fresh samples. Heat treatment such as steaming increased total carotenoids contents, especially trans-$\beta$-carotene (p<0.05). The carotenoid contents of the frozen spinach increased even after the microwaved treatment (p<0.05). These increases were likely to result from the increased extraction efficiency and inactivation of enzymes capable of carotenoids degrading during the heat treatments.

• Journal of Life Science
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• v.18 no.8
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• pp.1147-1153
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• 2008

The purpose of this investigation was to determine the effect of feeding trans fat on serum and tissue lipid profiles and fatty acid composition in mice. Forty-five male mice aged at 4 weeks were fed on the 10% palm oil (n-3 deficient group), 20% dried mackerel (n-3 adequate group) and 5% trans fat (trans group) for three months. Total triglyceride, cholesterol and LDL-cholesterol levels were increased in serum, liver and heart of the n-3 deficient and trans groups compared with the n-3 adequate group, while liver HDL-cholesterol levels were lowest in the trans group (p<0.05). In liver and heart, trans group showed higher levels of total cholesterol and LDL-cholesterol compared with the n-3 deficient group (p<0.05). In fatty acid compositions of serum, heart, liver and kidney, the intake of trans fat led to increased percentages of 18:1n-9trans and 18:2n-6trans. The trans group showed similar patterns to the n-3 deficient group, except an increased percentage of 18:2n-6cis. Generally, the n-3 deficient and trans groups showed increased percentages of n-6 fatty acids and decreased percentages of n-3 fatty acids, specially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) compared to the n-3 adequate group (p<0.05). These results indicate that intake of trans fat increased total triglyceride, cholesterol and LDL-cholesterol levels, which may affect risk for cardiovascular mortality.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.493-499
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• 2011

To improve the bandwidth efficiency of conventional orthogonal modulation, the MCTO(Multi-Code Trans-Orthogonal) modulation, which is modified orthogonal modulation, was proposed. However, the RF(Radio Frequency) power amplifier for the MCTO modulation is too complex to reject the amplitude distortion due to the non-constant amplitude property of the MCTO. Therefore, in this paper, CAMCTO(constant-amplitude multi-code trans-orthogonal) modulation is proposed by using the constant-amplitude encoding algorithm for multi-code signal. Additionally, the performance of the proposed CAMCTO modulation is compared with those of the orthogonal modulation and the MCTO modulation by using the computer simulation. The computer simulations show that the bandwidth efficiency of the proposed CAMCTO modulation is better than that of the conventional orthogonal modulation.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3239-3244
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• 2011

Dinuclear Ni(II)-thiophene halides, which contain linear bridging thienylenes, trans,trans-[$(PR_3)_2$(X)Ni-Y-Ni(X)$(PR_3)_2$] {X = Cl, Br; $H_2Y$ = 5,5'-dichloro-2,2'-bithiophene ($H_2bth$); $H_2tth$ = 5,5"-dichloro-2,2':5',2''-terthiophene ($H_2tth$)} were prepared by the oxidative addition of dihalobithiophene ($H_2bth$) or dihaloterthiophene ($H_2tth$) to [$Ni(COD)_2$] in the presence of tertiary phosphines. Subsequent reactions of $NaN_3$ with the dinuclear Ni(II)-thiophene chlorides gave the corresponding Ni(II)-azido complexes, trans,trans-[$(PR_3)_2(N_3)$Ni-Y-Ni$(N_3)(PR_3)_2$], whose reactivity toward trimethylsilyl pseudohalides such as trimethylsilyl isothiocyanates and cyanides was investigated. In addition, the reaction of trans-[$BrNi(PEt_3)_2-C_4H_2S-C_4H_2S$-CHO], a thienyl Ni(II) complex containing a terminal aldehyde group, with phosphonium ylide was examined.

• Preventive Nutrition and Food Science
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• v.7 no.4
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• pp.447-450
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• 2002

Previously, a methanol extract from seeds of Paeonia lactiflora was shown to have a potent inhibitory activities against tyrosinase and soybean lipoxygenase (SLO). Seven stilbenes, trans-resveratrol-4-Ο-$\beta$-D-glucoside, trans resveratrol, trans-$\varepsilon$-viniferin, cis-$\varepsilon$-viniferin, gnetin H, suffruticosol A and B were isolated from the seeds as active principles for inhibition of the enzymatic activity. Among them, the resveratrol trimer, gnetin H exhibited the most potent inhibitory activities against tyrosinase and SLO, respectively. Additionally, the resveratrol dimers, trans-$\varepsilon$-viniferin and cis-$\varepsilon$-viniferin exhibited significant inhibitory activity against the two oxidative enzymes. Meanwhile, three other stilbene derivatives, such as trans-resveratrol, suffruticosol A and suffruticosol B had also weak inhibition activity. The least inhibitory activity was observed in transresveratrol-4-Ο-$\beta$-D-glucoside. These results suggest that resveratrol dimers and trimer in the seeds of Paeonia lactiflora are potentially useful therapeutic agents against pathological disorders such as hyperpigmentation and inflammation.