• Journal of Life Science
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• v.9 no.4
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• pp.473-480
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• 1999

This study was designed to investigate the effects of pine (Pinus densiflora Sieb et Zucc) needle extract (PNE) on membrane fluidity and oxidative stress in liver membranes of Sprague-Dawley (SD) rats as a study on investigation of anti-aging effect and determination of chemical structures of PNE through the animal experiments. Male SD rats were fed basic diets (control group) and experimental diets (0.5% and 1.0%-PNE group) for 6 weeks. Administrations of 0.5% and 1.0%-PNE resulted in a marked decreases (15∼25% and 23∼26%, respectively) in cholesterol accumulations of liver mitochondria and microsomes compared with control group. Membrane fluidities were significantly increased (15∼25%) in liver microsomes of 0.5% and 1.0%-PNE groups compared with control group. Formations of basal and induced oxygen radicals (BOR and IOR) in liver mitochondria were significantly inhibited (11∼12% and 10∼15%, respectively) by administrations of 0.5% and 1.0%-PNE compared with control group. Lipid peroxide (LPO) levels were remarkbly decreased about 20% in liver mitochondria and microsomes of 0.5% and 1.0%-PNE groups compared with control group. Oxidized protein levels calculated with carbonyl group were significantly decreased about 15% in liver mitochondria of 1.0%-PNE group compared with control group. These results suggest that PNE may play a effective role in a attenuating a oxidative stress and increasing a membrane fluidity.

• Archives of Pharmacal Research
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• v.24 no.2
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• pp.100-104
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• 2001

Differential pulse polarographic(DPP) analytical procedure for the rifampicin antibiotic, which can be applied to monitor its synthetic process from the starting antibiotic of rifamycin B or rifamycin SV has been developed based on the electrochemical reduction of an azomethine group. Rifampicin exhibited a cathodic peak due to the azomethine group in the side chain of 3-[(4-methyl-1-piperazinyl)imino]methyl moiety and another cathodic peak due to the carbonyl group in rifamycin SV by DPP. The experimental peak potential shift of an azomethine reduction was -73 mV/pH in the pH range between 3.0 and 7.5, agreeing with involvement of 4 e-and 5 $H^5$ in its reduction. By the cyclic voltammetric(CV) studies, the azomethine and the carbonyl reductions in rifampicin were processed irreversibly on the mercury electrode. The plot of peak currents vs. concentrations of rifampicin ranging $1.0{\times}10^{-7} M~$1.0{\times}10^{-5} M yielded a straight line with a correlation coefficient of 0.9996. The detection limit was $1.0{\times}10^{-8} M with a modulation amplitude of 50 mV DPP has been successfully applied for the determination of rifampicin in the pharmaceutical preparations.

• Journal of Veterinary Clinics
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• v.26 no.3
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• pp.200-204
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• 2009

This study was performed to evaluate the effects of reduced L-glutathione on the oxidant/antioxidant status(superoxide dismutase(SOD), catalase(CAT), glutathione peroxidase(GPx), protein carbonyl and lipid hydroperoxide(LPO) concentration), renal function(blood urea nitrogen(BUN) and serum creatinine levels), and microscopy of renal tissues in pigs undergoing unilateral renal ischemia-reperfusion(I/R). Sixteen Landrace and Yorkshire mixed-breed pigs were divided randomly into two groups: untreated control group and reduced L-glutathione-treated group(4 mg/kg IV). Each group had 8 pigs. Pigs were unilaterally nephrectomized and the kidney was subject to 30 min of renal pedicle occlusion. Blood samples for biochemical assay were collected on days 1, 3, 5, 7, and 14 post nephrectomy. Renal I/R injury were evaluated histopathologically by the microscopic observation of renal tissue sections and biochemically by the measurement of the plasma creatinine and urea levels. Parameters of oxidative stress such as SOD, GPx, CAT, protein carbonyl and LPO were measured. The elevation of creatine and BUN levels was lower in the treated group, compared with the control group. The activities of antioxidant-enzyme were higher in the treated group, compared with the control group. In histological findings, the severity of damage in the reduced L-glutathione treated group was less when compared to the control group.

• Bulletin of the Korean Chemical Society
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• v.15 no.2
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• pp.154-161
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• 1994

Studies have been conducted to explore single electron transfer (SET) induced photocyclization reactions of N-(trimethylsilylmethylthioalkyl)phthalimides (alkyl=ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl). Photocyclizations occur in methanol in modest to high yields to produce cyclized products in which phthalimide carbonyl carbon is bonded to the carbon of side chain in place of the trimethylsilyl group. Mechanism for these photocyclizations involving intramolecular SET from sulfur in the ${\alpha}$-silylmethylthioalkyl groups to the singlet excited state phthalimide moieties followed by desilylation of the intermediate ${\alpha}$ -silylmethylthio cation radicals and cyclization by radical coupling is proposed. In contrast, photoreactions of N-(trimethylsilylmethylthioalkyl)phthalimides in acetone follow different reaction routes to produce another cyclized products in which carbon-carbon bond formation takes place between the phthalimide carbonyl carbon and the carbon ${\alpha}$ to silicon and sulfur atoms via triplet carbonyl hydrogen abstraction pathway. The normal singlet SET pathway dominates this triplet process for photoreactions of these substances in methanol while the triplet process dominates the singlet SET pathway for those in acetone. The efficient and regioselective cyclization reactions observed for photolyses in methanol represent synthetically useful processes for construction of medium and large ring heterocyclic compounds.

• Archives of Pharmacal Research
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• v.18 no.6
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• pp.440-448
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• 1995

Fitty two flavones were synthesized from polyoxygenated dibenzoylmethanes which were obtained by a modified Baker-Venkatarman rearrangement, of 2-benzoyl oxyacetophenones. The following flavones among them showed good cytotoxic activities against L1210 and HL60 cells ; 2'-benzoyloxy-5,7-dimethoxyflavone $(8.2{\mu}g/ml,{\;}5.0 {\mu}g/ml)$, 2'-benzyloxy-5,7,8-trimethoxyflavone $(5,9 {\mu}g/ml,{\;}11.0{\mu}g/ml,{\;}2.7{\mu}g/ml)$, 2'-hydroxy-5,7,8-trimethoxyflavone $(9.8{\mu}/ml,{\;}6.2{\mu}g/ml)$, 2'-benzyloxy-5-hydroxyflavone $(5.2 {\mu}g/ml,{\;}3.6{\mu}g/ml)$, and 5,2'-dihydroxyflavone $(5.1{\mu}g/ml,{\;}4.0{\mu}g/ml)$. Presence of 5-methoxy group potentiated the cytotoxic activity, while the existence of 7-methoxy group decreased the activity. 5-Hydroxy or methoxy activates 4-carbonyl group, while 7-methoxy group deactivates the acrbonyl group. From these observation it was concluded that the activation of carbonyl group at C-4 of a flavone is important for the enahncement of the cytotoxic activity. The presence of both 5-hydroxy and 2-benzyloxy-or 2-hydroxy group enhanced the antitumor activity; 2'-benzyloxy-5-hydroxy-7-methoxyflaone 9T/C=144%), 5.2'-dihydroxy-7-methoxyflavone (T/C=132%) and 5,2'-dihydroxy-6,78,6' trtramethoxyflvone (T/C = 172%) 2'hexanolytion of 5,2'-dihydroxy-flavones did not improve the natitumor activity; 2' hexanoyloxy-5-hydroxy-7-methoxyflavone showed T/C = 132%, about the same as that of 5,2'-dihydroxy-7-methoxyflvone (T/C=130%)

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.477-482
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• 2009

Toll-like receptors (TLRs) play a critical role in the induction of innate immune responses that are essential for host defense against invading microbial pathogens. In general, TLRs have two major downstream signaling pathways, namely MyD88- and TRIF-dependent pathways, leading to the activation of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and interferon regulatory factor 3 (IRF3) and the expression of inflammatory mediators. TLR4 dimerization is required for the activation of downstream signaling pathways and may be one of the first lines of regulation in activating TLR-mediated signaling pathways. In this paper, the molecular targets of curcumin, 6-shogaol, and cinnamaldehyde in TLR signaling pathways will be discussed. Curcumin, 6-shogaol, and cinnamaldehyde with ${\alpha},{\beta}$-unsaturated carbonyl groups inhibit the dimerization of TLR4 induced by lipopolysaccharide, resulting in the downregulation of NF-${\kappa}B$ and IRF3. These results suggest that phytochemicals with the structural motif conferring Michael addition inhibit TLR4 dimerization, suggesting a novel mechanism for the anti-inflammatory activity of phytochemicals.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5343-5348
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• 2015

Promoter hypermethylation of the runt-related transcription factor 3 (RUNX3) gene is associated with increased risk of hepatocellular carcinoma (HCC). Oxidative stress plays a vital role in both carcinogenesis and progression of HCC. However, whether oxidative stress and RUNX3 hypermethylation in HCC have a cause-and-effect relationship is not known. In this study, plasma protein carbonyl and total antioxidant capacity (TAC) in patients with hepatitis B virus (HBV)-associated HCC (n=60) and age-matched healthy subjects (n=80) was determined. RUNX3 methylation in peripheral blood mononuclear cells (PBMC) of subjects was measured by methylation-specific PCR. Effect of reactive oxygen species (ROS) on induction of RUNX3 hypermethylation in HCC cells was investigated. Plasma protein carbonyl content was significantly higher, whereas plasma TAC was significantly lower, in HCC patients than healthy controls. Based on logistic regression, increased plasma protein carbonyl and decreased plasma TAC were independently associated with increased risk for HCC. PBMC RUNX3 methylation in the patient group was significantly greater than in the healthy group. RUNX3 methylation in hydrogen peroxide ($H_2O_2$)-treated HepG2 cells was significantly higher than in untreated control cells. In conclusion, increase in oxidative stress in Thai patients with HBV-associated HCC was demonstrated. This oxidative increment was independently associated with an increased risk for HCC development. RUNX3 in PBMC was found to be hypermethylated in the HCC patients. In vitro, RUNX3 hypermethylation was experimentally induced by $H_2O_2$. Our findings suggest that oxidative stress is a cause of RUNX3 promoter hypermethylation in HCC cells.

• Archives of Pharmacal Research
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• v.29 no.10
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• pp.840-844
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• 2006

For the exploration of pharmacophoric moiety of malloapelta B (1) possessing the inhibitory activity of $NF-{\kappa}B$ activation, structural variation of ${\alpha},{\beta}-unsaturated$ carbonyl motif was attempted. 1 was reduced by catalytic hydrogenation, sodium borohydride, and lithium aluminumhydride. Catalytic hydrogenation with 30 psi or 15 psi of $H_2$ gas of 1 generated 8-butyl-5,7-dimethoxy-2,2-dimethylchroman (2) and 1-(5,7-dimethoxy-2,2-dimethylchroman-8-yl)butan-1-one (3), respectively. Reduction with sodium borohydride occurred at the double bond of ${\alpha},{\beta}-unsaturated$ ketone of 1 to give 1-(5,7-dimethoxy-2,2-dimethyl-2H-chromen-8-yl)butan-1-one (4). Reduction of 1 with lithium aluminumhydride and then quenched with methanol and water produced unexpected products, 1-(5,7-dimethoxy-2,2-dimethyl-2H-chromen-8-yl)-3-methoxy-1-butene (5) and 1-(5,7-dimethoxy-2,2-dimethyl-2H-chromen-8-yl)-3-hydroxy-1-butene (6). These are formed from the isomerization of initial product 9 through the continuous conjugate carbocation intermediate 11. Addition of ethylmagnesium bromide and dimethyl malonate anion to 1 gave the conjugate adducts 7 and 8. Ethylmagesium bromide and sodium borohydride reduction unusually gave the conjugate addition due to steric congestion around carbonyl group of 1. Compound 2 exhibits the reduced inhibitory activity against $NF-{\kappa}B$ activation and the others do not show the activity. Therefore ${\alpha},{\beta}-unsaturated$ carbonyl group of 1 should be important for its inhibitory activity.

• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1379-1384
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• 2004

Rearrangements of 1,3-oxathiolane sulfoxides 8 and 9 in the presence of base are described from a mechanistic viewpoint of sigmatropic and elimination reactions. In the presence of triethylamine the (Z)-sulfoxide 8 gave the corresponding thiolsulfinate 10 by way of dimerization of the sulfenic acid intermediate 2 at room temperature while the (E)-sulfoxide 9 was recovered even after refluxing in ethyl acetate by the reversal of the [2,3]-sigmatropic rearrangement of the sulfenic acid 4. Triethylamine promoted the developing charge separation in the transition state of the sigmatropic rearrangement of the (Z)-sulfoxide 8 to facilitate the ring opening to the sulfenic acid 2. The reason for more facile ring opening of the (Z)-sulfoxide 8 in comparison with the corresponding (E)-sulfoxide 9 is attributable to the differences in the reactivity of the hydrogen adjacent to the carbonyl group. Triethylamine was not strong base to deprotonate the carbonyl-activated methylene hydrogen of the (E)-sulfoxide 9 but enough to catalyze the sigmatropic process of the sulfoxides. The sulfenic acid 2 dimerized to the thiolsulfinate 10 while the sulfenic acid 4 proceeded the sigmatropic ring closure. In the presence of strong base such as potassium hydroxide, the elimination reaction was predominant over the sigmatropic rearrangement. In this reaction condition, both sulfoxides 8a and 9a gave a mixture of the disulfide 12, the isomeric disulfide 14, and the sulfinic acid 13. Under the strong alkaline condition an elimination of activated hydrogen from the carbon adjacent to the carbonyl group to furnish the sulfenic acid 2a and the isomeric sulfenic acid 18. The formation of the transient intermediate in the reaction was proven by isolation of the isomeric disulfide 14. The reactive entity was regarded as the sulfenic acid rather than sulfenate anion under these reaction conditions.

• Journal of the Korean Chemical Society
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• v.23 no.6
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• pp.358-367
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• 1979

EHT and CNDO/2 calculations have been performed to determine conformations of acetamides and diacetamides, and of their protonated forms. Results show that: protonation is always favored on the cis position with respect to N due to greater attractive potential between $H^+$ and N; the trans-trans conformer of diacetamides gives the most preferred protonated form although the cis-trans conformer is the most stable one for the unprotonated diacetamides. Protonation on a carbonyl oxygen is predicted to increase both charge and orbital controlled $S_N$SN reactivities of the protonated carbonyl carbon due to increases in positive charge and AO coefficient of ${\pi}$-LUMO of the carbon atom. In the acid catalyzed hydrolysis of diacetamides therefore it appears highly probable that the rate determining attack by a water molecule occurs at the carbon of the protonated carbonyl group and the carbonyl carbon-nitrogen bond scission follows subsequently. This mechanism is consistent with that generally accepted for the hydrolysis of amides in dilute acid solution but disagrees with that proposed by Laureut et al., for acid hydrolysis of N-acetyl-lactams.