• 제목/요약/키워드: methylation : phenolics

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Chebulae Fructus중 페놀 물질 확인시의 Methylation법 비교 (Methylation Methods on Identification of Phenolics in Chebulae Fructus)

  • 김정숙
    • 동아시아식생활학회지
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    • 제4권1호
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    • pp.79-86
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    • 1994
  • Food quality in food processing and storage were affected by the kinds of phenolics involved. To analyze phenolics of Chebulae Fructus by the way of GC-MSm methylation and trimethylsilyation(TMS) are necessary. The methods of methylation were dimethyl sulfate method and diazomethane method. so this study was undertaken to research the better methylation method before measuring GC-MS. But dimethyl sulfate method of methylation was not sufficient to analyze phenolics. So the phenolics of Chebulae Fructus were analyzed by the diazomethane methylation method and TMS with the pyridine, N-O-bis-trimethylsilyl-acetamide(BSTFA) and trimethylchlorosilane(TMCS). With the exception of pyrogallol and phloroglucinol in insoluble phenolics of Chebulae Fructus, the greater part of phenolics. analysis could be analyzed by GC-MS in company with diazomethane methylation method and TMS.

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O-Methyltransferases from Arabidopsis thaliana

  • Kim, Bong-Gyu;Kim, Dae-Hwan;Hur, Hor-Gil;Lim, Jun;Lim, Yoong-Ho;Ahn, Joong-Hoon
    • Journal of Applied Biological Chemistry
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    • 제48권3호
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    • pp.113-119
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    • 2005
  • O-methylation mediated by O-methyltransferases (OMTs) is a common modification in natural product biosynthesis and contributes to diversity of secondary metabolites. OMTs use phenylpropanoids, flavonoids, other phenolics and alkaloids as substrates, and share common domains for S-adenosyl-L-methionine (AdoMet) and substrate binding. We searched Arabiposis genome and found 17 OMTs genes (AtOMTs). AdoMet- and substrate-binding sites were predicted. AdoMet binding domain of AtOMTs is highly conserved, while substrate-binding domain is diverse, indicating use of different substrates. In addition, expressions of six AtOMT genes in response to UV and in different tissues were investigated using real-time quantitative reverse transcriptase-polymerase chain reaction. All the AtOMTs investigated were expressed under normal growth condition and most, except AtOMT10, were induced after UV illumination. AtOMT1 and AtOMT8 were expressed in all the tissues, whereas AtOMT10 showed flower-specific expression. Analysis of these AtOMT gene expressions could provide some clues on AtOMT involvement in the cellular processes.