UMR 1219 Oenologie, Institut de Sciences de la Vigne et du Vin Bordeaux-Aquitaine, Université de Bordeaux, 210 chemin de leysotte CS 50008, 33882 Villenave d'Ornon Cedex, France.
Anal Chim Acta. 2010 Feb 15;660(1-2):102-9. doi: 10.1016/j.aca.2009.11.016. Epub 2009 Nov 16.
As volatile thiols are nucleophiles, they are capable of additional reactions with electrophiles. In enology, this concerns reactions between volatile or non-volatile thiols and oxidized phenolic compounds. Initial studies concerning the reactivity of volatile thiols with polyphenols showed that (+)-catechin played a detrimental role in the level of 3-sulfanylhexan-1-ol (3SH), in the absence of sulfur dioxide. Our experiment revealed that (-)-epicatechin was more reactive with volatile thiols than (+)-catechin. Furthermore, Fe (III) was shown to play a crucial role in catalyzing polyphenol oxidation reactions, by affecting the direct reaction of phenolic compounds with oxygen. It was noted that, even if the volatile thiols studied were members of the same chemical family, they exhibited a different behavior pattern under oxidation conditions. 2-furanmethanethiol (2FMT) was more reactive than 3-sulfanylhexan-1-ol with both (+)-catechin and (-)-epicatechin. In contrast, 4-methyl-4-sulfanylpentan-2-one (4MSP) was less reactive with these phenolics. Additionally, the vital role of sulfur dioxide in protecting 3-sulfanylhexan-1-ol, 2-furanmethanethiol, and 4-methyl-4-sulfanylpentan-2-one was demonstrated in the model medium.
由于挥发性硫醇是亲核试剂，它们能够与亲电试剂发生额外的反应。在葡萄酒酿造学中，这涉及到挥发性或非挥发性硫醇与氧化酚类化合物之间的反应。最初关于挥发性硫醇与多酚反应性的研究表明，在没有二氧化硫的情况下，（+）-儿茶素在 3-巯基己烷-1-醇（3SH）的水平上起着有害的作用。我们的实验表明，（-）-表儿茶素比（+）-儿茶素更能与挥发性硫醇反应。此外，Fe（III）被证明在催化多酚氧化反应中起着至关重要的作用，通过影响酚类化合物与氧的直接反应。值得注意的是，即使研究的挥发性硫醇属于同一化学家族，它们在氧化条件下也表现出不同的行为模式。2-糠硫醇（2FMT）比 3-巯基己烷-1-醇与（+）-儿茶素和（-）-表儿茶素的反应性更强。相比之下，4-甲基-4-巯基戊烷-2-酮（4MSP）与这些酚类化合物的反应性较低。此外，二氧化硫在模型介质中对 3-巯基己烷-1-醇、2-糠硫醇和 4-甲基-4-巯基戊烷-2-酮的保护作用至关重要。
