Identification of natural lactoylcholine in lactic acid bacteria-fermented food

Acetylcholine (AcCh) is a major neurotransmitter and an agonist of nicotinic and muscarinic receptors in non-neuronal systems. Artificially synthesized lactoylcholine (LaCh) has potent nicotinic activity equal to that of AcCh. In this study, we report the isolation and purification of natural AcCh and LaCh from a lactic-fermented food known to reduce blood pressure. To our knowledge, we are the first to isolate natural LaCh. The choline esters were isolated using a novel purification procedure combining a weak cation-exchange cartridge with ODS and pentafluorophenyl HPLC columns, and the structure of LaCh was identified via various analyses. Assessment of d- and l-LaCh showed that the isolated LaCh was an enantiomer mixture with a D/L ratio of 1.6. d-LaCh induced vasorelaxation of thoracic aortas from spontaneously hypertensive rats (EC50 = 3.83 × 10−7 M), while l-LaCh did not. Our results suggest that choline esters could be new functional ingredients in lactic-fermented foods.