• 제목/요약/키워드: Retro Diels-Alder reaction

검색결과 4건 처리시간 0.02초

하고초의 생리활성 성분 Triterpenic Acids의 FAB-MS를 이용한 구조 규명 (Structural determination of triterpenic acids in Prunellae Spica by fast atom bombardment tandem mass spectrometry)

  • 안영민;이강노;홍종기
    • 분석과학
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    • 제21권4호
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    • pp.245-258
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    • 2008
  • 본 연구에서는 하고초의 지표성분인 triterpenic acids 5종을 컬럼 크로마토그래피와 역상 HPLC를 이용하여 추출 및 분리했고, 이들 성분의 순도는 90% 이상임을 HPLC를 이용하여 확인했다. 고속원자충돌 이온화법-고분해능 질량분석기(FAB-HRMS)를 사용하여 지표성분의 분자량 및 원소조성을 결정했으며, 지표성분의 구조 분석은 FAB-MS/MS 의해 음이온 및 양이온 모드에서 수행하였다. Triterpenic acid류의 충돌유발분해(collision-induced dissociation, CID) 탄뎀질량분석(MS/MS) 스펙트럼에서 protonated molecule인 $[M+H]^+$ 및 deprotonated molecule인 $[M-H]^-$ 이온의 CID는 주로 retro Diels-Alder (RDA), 탈수 (dehydration) 및 탈탄산(decarboxylation) 반응에 의한 다양한 생성이온들이 나타났다. 특히, $[M-H]^-$이온의 CID-MS/MS 스펙트럼에서는 charge-remote fragmentation (CRF) 현상에 의한 이온들도 특성이온으로 나타났다. 이들 CID-MS/MS 스펙트럼의 해석을 통하여 하고초의 지표성분인 triterpenic acids의 구조 규명을 수행하였다.

General Fragmentations of Alkaloids in Electrospray Ionization Tandem Mass Spectrometry

  • Shim, Hee Jung;Lee, Ji Ye;Kim, Byungjoo;Hong, Jongki
    • Mass Spectrometry Letters
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    • 제4권4호
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    • pp.79-82
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    • 2013
  • Various types of alkaloids observed in several herbal medicines were analyzed by electrospray ionization tandem mass spectrometry in positive ion mode. In the present study, MS/MS spectralpatterns were investigated for eight-types of alkaloids (aporpine, protoberberine, tetrahydroprotoberberine, benzylisoquinoline, protopine, phthalide, morpine, and bisbenzylisoquinoline). For aporpine- and protoberberine-type alkaloids, main fragmentations occurred at substituted groups on rigid ring structures, not showing ring fusion. Interesting fragmentations due to iminolization and retro-Diels-Alder (RDA) reaction were observed in MS/MS spectra of protopine- and tetrahydroprotobereberine-type alkaloids. Also, several types of fragmentations such as inductive cleavage and ${\alpha}$-cleavage, or bond cleavage between two ring structures were observed depending on their structural characteristics. These fragmentation patterns are expected to allow instant classification of the specific alkaloid type in various MS/MS spectra of alkaloids.

Characterization of Low Molecular Weight Polyphenols from Pine (Pinus radiata) Bark

  • Mun, Sung-Phil;Ku, Chang-Sub
    • Food Science and Biotechnology
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    • 제15권3호
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    • pp.424-430
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    • 2006
  • Low molecular weight polyphenols were isolated from hot water extracts of radiata pine (Pinus radiata) bark using a Sephadex LH-20 column and characterized by $^1H$ and $^{13}C$ NMR, UV, FT-IR, and GC-MS analyses. Major compounds isolated and identified were protocatechuic acid, trans-taxifolin, and quercetin. Trans-taxifolin, an important intermediate in biosynthetic route of proanthocyanidin (PA), was isolated in large quantities and indicates that PA is a major component of radiata pine bark. Small amounts of polyphenols were identified by GC-MS analysis. The presence of p-hydroxybenzoic acid, vanillic acid, protocatechuic acid, cis- and trans-feruic acid, p-coumaric acid, trans-caffeic acid, (-)-epicatechin, (+)-catechin, trans- and cis-taxifolin, (+)-gallocatechin, and quercetin was confirmed by comparison of mass fragmentation patterns and retention times (RT) with authentic samples. In addition, the presence of astringenin, astringenin glycoside, trans- and cis-leucodelphinidin was strongly assumed from characteristic mass fragment ions due to their conjugated structure and retro Diels-Alder reaction, and also from biosynthetic route of PA. GC-MS analysis allowed us to detect small amounts of phenolic acids and flavonoids and eventually discriminate trans- and cis-configuration in the identified polyphenols.