An NMR assay for quantitating lipase activity in biphasic macroemulsions

A novel nuclear magnetic resonance (NMR) assay has been developed to monitor lipase-catalyzed esterification reactions without the need to extract and purify the individual components. The technique measures ratios of ester:alcohol signals and has been shown to be both efficient and reproducible. The assay has proven useful as a quick screen for the effect of varying conditions on the extent of esterification in various biphasic solvent systems and can be applied to both saturated and unsaturated long-chain fatty acid and alcohol substrates. The NMR ratio technique has been used to quantitate the extent of reaction in theCandida cylindracea lipase-catalyzed synthesis of oleyl palmitate, stearyl palmitate, oleyl oleate, oleylgamma-linolenate and oleyl linoleate. The identity of these products was confirmed by high-resolution mass spectrometry.