Enzymatic preparation of food‐grade l‐α‐glycerylphosphorylcholine from soy phosphatidylcholine or fractionated soy lecithin

l‐α‐Glycerylphosphorylcholine (l‐α‐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‐α‐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‐α‐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‐α‐GPC under optimal conditions: temperature, 55°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‐α‐GPC (from soy phosphatidylcholine) or 52.4 area% glycerophosphodiesters, including l‐α‐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.