Univ. Bordeaux , Unité de Recherche Oenologie, EA 4577, USC 1366 INRA, ISVV, 33882 Villenave d'Ornon Cedex , France.
J Nat Prod. 2019 Feb 22;82(2):265-275. doi: 10.1021/acs.jnatprod.8b00682. Epub 2019 Jan 28.
Eight new triterpenoids (1-8), the known genin (9), and two known functionalized triterpenoids (10 and 11) were isolated from a Quercus petraea heartwood extract. The structures of the new compounds were unequivocally elucidated using HRESIMS and 1D/2D NMR experiments. Sensory analyses were performed in a non-oaked wine on the pure compounds 1-11. Except compounds 1 and 11, all molecules exhibited a sweet taste at 5 mg/L that was particularly intense for compounds 3 and 9. Using LC-HRMS, compounds 1-11 were observed in an oak wood extract and in oaked red wine and cognac. They were also semiquantified in several samples of sessile ( Q. petraea) and pedunculate ( Q. robur) oak wood extract. All compounds were found in quantities significantly higher in sessile than in pedunculate oak wood. These results support the hypothesis of their contribution to the increase in sweetness during oak aging and show that they can be used as chemical markers to identify the species of oak used for cooperage.
从欧洲栓皮栎心材提取物中分离得到了 8 种新的三萜类化合物（1-8）、1 种已知的苷元和 2 种已知的功能化三萜类化合物（10 和 11）。利用高分辨质谱（HRESIMS）和 1D/2D NMR 实验明确鉴定了这些新化合物的结构。在非橡木陈酿葡萄酒中对纯化合物 1-11 进行了感官分析。除了化合物 1 和 11 之外，所有分子在 5mg/L 时均表现出甜味，其中化合物 3 和 9 的甜味尤其强烈。利用 LC-HRMS 在橡木木提取物、橡木陈酿红酒和干邑白兰地中观察到了化合物 1-11。它们也在几种无梗（ Q. petraea）和有梗（ Q. robur）橡木木提取物样品中进行了半定量分析。所有化合物在无梗橡木木提取物中的含量明显高于有梗橡木木提取物。这些结果支持了它们在橡木陈酿过程中增加甜度的假设，并表明它们可以用作化学标记物来识别用于制桶的橡木种类。
