Metabolic profile of lettuce leaves by high-field NMR spectra

A detailed analysis of the proton high-field NMR spectra of aqueous and organic extracts of lettuce leaves is reported for the first time. A combination of COSY, TOCSY, H-1-C-13 HSQC, H-1-C-13 HMBC bidimensional sequences and DOSY was used to assign each spin system and to separate the components of the complex patterns. A large number of water-soluble metabolites belonging to different classes such as carbohydrates, polyols, organic acids and amino acids were fully assigned. Moreover, the complex spectra of metabolites extracted in organic solvents belonging to sterols, fatty acids, diacylglycerophospholipids, galactosyldiacylglycerols, sulpholipids, pheophytins, carotenoids and hydrocarbons were also assigned.