Enhancement of pancreatic lipase inhibitory activity of curcumin by radiolytic transformation

The naturally occurring yellow dietary diarylheptanoid curcumin (1) was converted by gamma-ray to two new gamma-lactones, curculactones A (2) and B (3), as well as four known transformates, erythro-1-(3-methoxy-4-hydroxy- phenyl)-propan-1,2-diol (4), threo-1-(3-methoxy-4-hydroxy-phenyl)-propan-1,2-diol (5), vanillic acid (6), and vanillin (7). The structures of the two new gamma-lactone derivatives were elucidated on the basis of spectroscopic methods. The steroisomeric phenylpropanoids 4 and 5 exhibited significantly enhanced inhibitory activity against pancreatic lipase when compared to parent curcumin. (C) 2010 Elsevier Ltd. All rights reserved.