Fluorinated and deoxysucrose analogues have been proven useful in probing the substrate specificity and roles of sucrose processing enzymes and transporters in plants. To synthesize an 18F-labeled fluorodeoxysucrose analogue suitable for in vivo studies, an acyl-protected, disaccharide-based radiofluorination precursor (sucrose 1′-O-trifluoromethanesulfonyl-2,3,4,6,3′,4′,6′-hepta-O-acetate; 2) was prepared by regioselective mono-deacetylation of sucrose octaacetate using a commercial esterase enzyme followed by conversion of the resultant sucrose heptaacetate to the corresponding triflate. Reaction of this triflate precursor with [18F]fluoride followed by base hydrolysis to remove the acetate groups and HPLC purification gave 1′-[18F]fluoro-1′-deoxysucrose (4) in an overall synthesis time of 80 min and with a median decay corrected yield of 26% (n = 4). This study demonstrates the use of an enzymatic approach to aid the synthesis of a regiospecific radiofluorination precursor starting from the readily available fully acetylated sugar, thus avoiding the need for a complex classical carbohydrate protection strategy to individually protect each hydroxyl group in the molecule. Copyright © 2012 John Wiley & Sons, Ltd.
氟化和脱氧蔗
糖类似物已被证明在探究植物中
蔗糖加工酶和转运蛋白的底物特异性及其作用方面非常有用。为了合成一种适合体内研究的18F标记的
氟脱氧蔗
糖类似物,制备了一种酰基保护的基于二糖的放射
氟化前体(
蔗糖 1'-O-三
氟甲磺酰-2,3,4,6,3′,4′,6′-七乙酰酸酯;2),该前体通过使用商业
酯酶对
蔗糖八乙酸酯进行区域选择性的单脱乙酰化而获得,随后将得到的
蔗糖七
乙酸酯转化为相应的三
氟酸盐。将该三
氟酸盐前体与[18F]
氟化物反应,并随后通过碱性
水解去除
乙酸酯基团,经过高效
液相色谱(HPLC)纯化,最终在总合成时间为80分钟的情况下获得了1′-[18F]
氟-1′-脱氧
蔗糖(4),其中位衰变修正产率为26%(n=4)。本研究展示了一种酶促方法,帮助从 readily available 的完全乙酰化糖出发合成一个区域特异性的放射
氟化前体,从而避免了对分子中每个羟基进行复杂的传统
碳水化合物保护策略的需要。版权 © 2012 John Wiley & Sons, Ltd.