Enzymatic preparation of food-grade l-alpha-glycerylphosphorylcholine from soy phosphatidylcholine or fractionated soy lecithin

摘要

l-alpha-Glycerylphosphorylcholine (l-alpha-GPC) is a biosynthetic precursor for the neurotransmitter acetylcholine in humans, making it a useful as a cognitive enhancer for treating patients with stroke and dementia, including Alzheimer's disease. The aim of this study was to prepare l-alpha-GPC via Novozym 435 (an immobilized Candida antarctica lipase B)-catalyzed hydrolysis of soy phosphatidylcholine or a fractionated soy lecithin, from which triacylglycerols were completely removed, followed by food-grade solvent extraction of l-alpha-GPC from the reaction products. The reaction was performed in n-hexane-water biphasic media in a stirred-batch reactor. Phosphatidylcholine was completely hydrolyzed to l-alpha-GPC under optimal conditions: temperature, 55 degrees C; water content, 100 wt% of the substrate weight; enzyme loading, 10 wt% of the substrate weight; and reaction time of 6 hr (for soy phosphatidylcholine) or 8 hr (for fractionated soy lecithin). Water-soluble fractions of the reaction products containing 98.6 area% l-alpha-GPC (from soy phosphatidylcholine) or 52.4 area% glycerophosphodiesters, including l-alpha-GPC (from fractionated soy lecithin), were obtained after phase separation of the media. The resulting products would be suitable for use as food-grade cognitive enhancers because of the use of enzymatic reaction and food-grade solvent extraction.