An Improved Synthesis of the Antimicrobial Thymol- and Carvacrol-?-D-Glucopyranosides
作者:Melanie Walker、Ashlee Robison、William R. Collins
DOI:10.2174/1570178613666160524160916
日期:2016.7.28
Thymol (1) and Carvacrol (2) are monoterpenoid natural products that display in vitro antimicrobial activity
against Campylobacter jejuni and coli, food-borne pathogens found in animal distal guts/avian crops that commonly contaminate
meat and poultry during processing. Recently, it has been shown that thymol-β-D-glucopyranoside (3), a glucosylated
variant of the free monoterpenoid, also induces Campylobacter reductions within collected gut contents. Unfortunately,
commercial sources of 3 are prohibitively expensive for large-scale use, and syntheses of glucosylated variants of
either thymol or carvacrol are low yielding. Herein we report on an improved synthesis of both 3 as well as carvacrol-β-
D-glucopyranoside (4). This synthesis utilizes phase transfer catalysis glycosylation conditions in lieu of the previously
reported, low-yielding and expensive Koenigs-Knorr reactions.
百里香酚(1)和香芹酚(2)是显示出对弯曲杆菌(Campylobacter jejuni 和 coli)具有体外抗菌活性的单萜类天然产物,这些弯曲杆菌是存在于动物远端肠道和鸟类嗉囊中的食源性病原体,通常在肉类和家禽加工过程中会发生污染。最近的研究显示,百里香酚-β-D-葡萄糖吡喃苷(3),作为自由单萜的葡萄糖苷化变体,也能在收集的肠道内容物中诱导弯曲杆菌的减少。不幸的是,3的商业来源在大规模使用时价格高昂,而百里香酚或香芹酚的葡萄糖苷化变体的合成产率较低。在此,我们报告了一种改进的合成方法,可以合成3和香芹酚-β-D-葡萄糖吡喃苷(4)。该合成方法利用相转移催化糖基化条件,以取代之前报告的、产率低且昂贵的Koenigs-Knorr反应。