Identification and quantification of feruloylated mono-, di-, and triacylglycerols from vegetable oils

The use of HPLC-MS to separate and identify the feruloylated acylglycerols formed during the transesterification of ethyl ferulate with TAG was examined. Novozym 435 (Candida antarctica lipase B)-catalyzed transesterifications of ethyl ferulate and soybean oil resulted in a mixture of feruloylated MAG, DAG, and TAG and diferuloylated DAG and TAG. These feruloylated acylglycerols have recently garnered much interest as cosmeceutical ingredients. The ratio of the various feruloylated acylglycerol species in the resultant oils is presumed to affect the oil's cosmetic efficacy as well as its physical (formulation) properties. Thus, it was desirable to develop an analytical method to separate, identify, and quantify the individual feruloylated acylglycerols to determine their relative ratios. The feruloylated acylglycerols were successfully separated and identified by HPLC-MS using a phenyl-hexyl reversed-phase column developed with a water/methanol/1-butanol gradient. The chromatograms of the feruloylated acylglycerols from soybean oil were convoluted by myriad fatty acids; therefore, feruloylated acylglycerols from triolein were studied as a model reaction. Hydrolysis of the feruloylated acylglycerols from triolein catalyzed by Lipase PS-C “Amano” I (Burkholderia cepacia), which showed no hydrolysis reactivity toward ethyl ferulate, allowed for the chromatographic assignment of the feruloyl acylglycerol positional isomers.