Precursors and Formation of Pyrithione and Other Pyridyl-Containing Sulfur Compounds in Drumstick Onion, Allium stipitatum
作者:Roman Kubec、Petra Krejčová、Petr Šimek、Lukáš Václavík、Jana Hajšlová、Jan Schraml
DOI:10.1021/jf200704n
日期:2011.5.25
that no pyridyl-containing thiosulfinates are present in homogenized bulbs in detectable quantities. Instead, various pyridine N-oxide derivatives are formed, including N-hydroxypyridine-2(1H)-thione (pyrithione), 2-(methyldithio)pyridine N-oxide, 2-[(methylthio)methyldithio]pyridine N-oxide, di(2-pyridyl) disulfide N-oxide, and di(2-pyridyl) disulfide N,N′-dioxide. This represents the first report
两个新的,结构上不寻常的半胱氨酸衍生物从鳞茎分离韭stipitatum(葱属SUBG。Melanocrommyum)和示出为小号- (2-吡啶基)半胱氨酸Ñ氧化物和小号- (2-吡啶基)谷胱甘肽Ñ氧化物。前一种化合物是天然存在的蒜氨酸酶底物的第一个例子,该底物含有N-氧化物官能团而不是S-氧化物基团。此外,S-甲基半胱氨酸S-氧化物(次甲基)和S在灯泡中发现了-(methylthiomethyl)cysteine 4-oxide(marasmin)。提出的数据表明,先前报道的S-(2-吡啶基)半胱氨酸S-氧化物的鉴定很可能是错误的。通过HPLC-MS,HPLC-PDA,DART-MS和NMR技术的组合研究了stistitum鳞茎破坏后的蒜氨酸酶介导的含吡啶基化合物的形成。已发现在均质化的球茎中不存在可检测量的含吡啶基的硫代亚磺酸盐。相反,形成各种吡啶N-氧化物衍生物,包括N-羟基吡啶-2(