• Genomics & Informatics
• /
• v.17 no.4
• /
• pp.38.1-38.6
• /
• 2019

DNA methylation is a relatively stable epigenetic modification that can regulate and stabilize gene expression patterns and hence establish cell identity. Because metabolic intermediates are key factors of DNA methylation and demethylation, perturbations in metabolic homeostasis can trigger alterations in cell-specific patterns of DNA methylation and contribute to disease development, including type 2 diabetes (T2D). During the past decade, genome-wide DNA methylation studies of T2D have expanded our knowledge of the molecular mechanisms underlying T2D. This review summarizes case-control studies of the DNA methylome of T2D and discusses DNA methylation as both a cause and consequence of T2D. Therefore, DNA methylation has potential as a promising T2D biomarker that can be applied to the development of therapeutic strategies for T2D.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.4
• /
• pp.337-343
• /
• 2006

Trimethylamine dehydrogenase (TMADH, EC 1.5.99.7), an iron-sulfur flavoprotein that catalyzes the oxidative demethylation of trimethylamine to form dimethylamine and formaldehyde, was purified from Methylophaga sp. strain SK1. The active TMADH was purified 12.3-fold through three purification steps. The optimal pH and temperature for enzyme activity was determined to be 8.5 and $55^{\circ}C$, respectively. The $V_{max}\;and\;K_m$ values were 7.9 nmol/min/mg protein and 1.5 mM. A genomic DNA of 2,983 bp from Methylophaga sp. strain SK1 was cloned, and DNA sequencing revealed the open reading frame (ORF) of the gene coding for TMADH. The ORF contained 728 amino acids with extensive identity (82%) to that of Methylophilus methylotrophus $W_3A_1$.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.4
• /
• pp.809-816
• /
• 2010

Microbial biotransformations can be used to predict mammalian drug metabolism. The present investigation deals with microbial biotransformation of valdecoxib using microbial cultures. Thirty-nine bacterial, fungal, and yeast cultures were used to elucidate the biotransformation pathway of valdecoxib. A number of microorganisms metabolized valdecoxib to various levels to yield nine metabolites, which were identified by HPLC-DAD and LC-MS-MS analyses. HPLC analysis of biotransformed products indicated that a majority of the metabolites are more polar than the substrate valdecoxib. Basing on LC-MS-MS analysis, the major metabolite was identified as a hydroxymethyl metabolite of valdecoxib, whereas the remaining metabolites were produced by carboxylation, demethylation, ring hydroxylation, N-acetylation, or a combination of these reactions. The hydroxymethyl and carboxylic acid metabolites were known to be produced in metabolism by mammals. From the results, it can be concluded that microbial cultures, particularly fungi, can be used to predict mammalian drug metabolism.

• YAKHAK HOEJI
• /
• v.52 no.1
• /
• pp.85-91
• /
• 2008

8-Acyl and 8-sulfonylamidowogonin analogues were synthesized as potential anti-inflammatory agents. Nitration of 5,7-dihydroxyflavone (chrysin) followed by methylation of phenol groups and reduction of nitro group yielded 8-aminowogonin analogues. Acylation and sufonylation of 8-aminowogonin followed by demethylation reactions gave the title compunds. The synthesized wogonin analogues showed much reduced inhibitory activity on prostaglandin $E_2\;(PGE_2)$ production.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.35 no.3
• /
• pp.74-78
• /
• 2003

The structural property of phenolic and non-phenolic lignin has an effect on the reaction rate of lignin by oxygen and chlorine dioxide respectively. Moreover, the undesirable degradation of cellulose followed by lignin degradation is influenced by chemical charge and reaction time. In this paper, several lignin model compounds were used to illuminate the interaction of oxygen and chlorine dioxide by varying the position of O and D(OD, DO, ODO and DOD), and gas chromatography method was used to investigate the degradation of lignin by determining the content of methoxyl groups in lignin. It was shown that structural properties of lignin models were more influential on the degradation and demethylation of lignin than the above combination. Combination of oxygen and chlorine dioxide, however, was more effective in degradation of lignin than only one stage, and three stages than two stages.

• Journal of the Korean Chemical Society
• /
• v.58 no.6
• /
• pp.569-574
• /
• 2014

The synthesis of O-desmethylangolensin (O-DMA) analogues from methoxy-substituted benzoic acids was described. Treatment of methoxy-substituted benzoic acids with 2 equiv of ethyllithium afforded methoxypropiophenones, which were subsequently transformed to ethyl 2-(methoxyphenyl)propionates via 1,2-rearrangement of the methoxyphenyl group using $Pb(OAc)_4/HClO_4$ in triethyl orthoformate. After hydrolysis with KOH, the 2-(methoxyphenyl)propionic acids were reacted with di-2-pyridyl carbonate to afford 2-pyridyl 2-(methoxyphenyl)propionates, which were acylated with methoxy-substituted phenylmagnesium bromides to give methoxy-${\alpha}$-methyldesoxybenzoins. The methoxy groups of these compounds were selectively or fully demethylated using boron tribromide to give diverse O-DMA analogues in high yields.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.12
• /
• pp.3618-3622
• /
• 2014

Simple and practical synthesis of natural benzofuran derivative eupomatenoid-6 via Horner-Emmons type condensation as the key step is described. The umpolung property of aldehyde derivative, ${\alpha}$-aminophosphonate was efficiently employed in this reaction. ${\alpha}$-Aminophosphonate of anisaldehyde subjected to Horner-Emmons type condensation with 5-bromo-2-methoxybenzaldehyde to yield the deoxybenzoin, which was further methylated and then underwent tandem demethylation-cyclodehydration to afford the benzofuran scaffold in excellent yield. Finally Suzuki coupling with propenyl boronic acid afforded eupomatenoid-6 with an overall yield of 56.8%.

• Korean Journal of Pharmacognosy
• /
• v.28 no.3
• /
• pp.156-161
• /
• 1997

For the search of hepatoprotective compounds from the folk medicines, 14 natural products which have been traditionally used as hepatoprotective drugs in Korea were extracted with methanol. The extracts were screened for the antioxidant activity on lipid peroxidation induced by Fenton reaction in rat homogenate and Ac2F cell toxicity by t-hydroperoxide. Dendrobium moniliforme and Castanea crenata were chosen for the further investigation and its therapeutic effects on the liver damage induced by carbon tetrachloride in rats were evaluated. Oral administration of the extracts reduced the aspartate aminotransferase(AST) and alanine aminotransferase(ALT) activities in the serum of the carbon tetrachloride intoxicated rat. And the treatment of the extracts prevented the decrease of aminopyrine N-demethylation and aniline hydroxylation activities of the carbon tetrachloride-intoxicated rat liver. These results suggest that oral administration of Dendrobium moniliforme and Castanea crenata is effective in recovering the liver function in $CCl_4-treated$ rats.

• YAKHAK HOEJI
• /
• v.8 no.3
• /
• pp.76-79
• /
• 1964

The metabolism of p-methoxycinnamic acid (p-MCA) has been studied in man and rabbits. Possible compounds were examined for metabolites by crystalization and by paper chromatography, which excreted after adminstration of p-MCA by stomach tube and intravenous injection. p-Methoxyhippuric acid was isolated from urine. Although pure glucuronide was not crystallized from urine, product was obtained by basic lead salt method, which gave p-methodxybenzoic acid (p-MBA) on hydrolysis and gave an intese naphthoresorcinol reaction. No evidence for the demethylation of p-MCA was found. These results are indicating that p-MCA may be mainly converted to p-MBA by ${\betha}$-oxidationand excreted as its conjugates with glycine and glucuronic acid. Its oxidation does not appear to be dependent on intestinal micro-organisms.

• Journal of the Korean Home Economics Association
• /
• v.34 no.4
• /
• pp.403-414
• /
• 1996

The softening of the femented vegetables and the fruits was resulted from the degradation of pectin substances, cellulose, hemicellulose by polygalacturonase(PG), pectinesterase(PE), Cx-cellulase, $\beta$-galctosidase. The conversion of insoluble pectin to soluble pectin in cell wall-middle lamella was a major factor in the changes of firmness. Ca2+ was substantially increased firmness. However, Ca2+ could be removed from cell wall by chelating agents such as oxalic acid and citric acid. And Ca2+ was replaced with Na+ by ion exchange reaction. Ca2+ deficient tissue was vulnerable to attack by PG. Preheating treatment and Ca2+ addition is most effective in inhibiting the vegetable food softening and in increasing middle lamella-cell wall regidity, which PE activation by preheating treatment and Ca2+ addition could created more anionic carboxyl groups for cationic materials binding such as Ca2+ and chitosan and for polypectategel formation. Excessive demethylation by PE was associated with loosening of middle lamella cell wall components and softening.