Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
J Nat Prod. 2020 Aug 28;83(8):2337-2346. doi: 10.1021/acs.jnatprod.9b01234. Epub 2020 Aug 17.
species accumulate a variety of secondary metabolites in their trichomes, and it is well known that acyl sugars are specialized metabolites secreted by the trichomes. However, very few reports provide detailed information on the chemical structure of polyacylated glucose derivatives, due to the α and β isomerization that can occur at the C-1 position. In this study, a strategy was established to isolate polyacylated glucose derivatives. According to the developed strategy, hydroxy groups were derivatized to a benzyloxy group using TriBOT. After isolation of the compounds in pure form and deprotection of the benzyloxy group, the chemical structures of pennelliisides A-C were determined as 2,3,4--triisobutyryl-d-glucose, 3--(8-methylnonanoyl)-2,4--diisobutyryl-d-glucose, and 3--decanoyl-2,4--diisobutyryl-d-glucose, respectively. Structural elucidation was performed using spectroscopic techniques, including 1D and 2D NMR, FD-MS, and GC-MS. It was also found that the fatty acid moiety contributes to the allelopathic properties of the isolated compounds.
植物的表皮毛中积累了多种次生代谢产物，酰基糖是由表皮毛分泌的特征性代谢产物，这是大家熟知的。然而，由于 C-1 位的α和β异构化，很少有报道详细描述多酰化葡萄糖衍生物的化学结构。在本研究中，建立了一种分离多酰化葡萄糖衍生物的策略。根据所开发的策略，使用 TriBOT 将羟基衍生为苄氧基。在化合物以纯形式分离并脱去苄氧基保护基后，鉴定出 pennelliisides A-C 的化学结构分别为 2,3,4--三异丁酰基-d-葡萄糖、3--(8-甲基壬酰基)-2,4--二异丁酰基-d-葡萄糖和 3--癸酰基-2,4--二异丁酰基-d-葡萄糖。通过光谱技术，包括 1D 和 2D NMR、FD-MS 和 GC-MS，进行了结构阐明。还发现脂肪酸部分有助于分离化合物的化感特性。
