Facile synthesis of deuterated and [ 14 C]labeled analogs of vanillin and curcumin for use as mechanistic and analytical tools

Curcumin is a dietary diphenol with antioxidant, antinflammatory, and antitumor activity. We describe facile procedures for the synthesis of [ 14 C 2 ]curcumin (4 mCi/mmol), [d 6 ]curcumin, [d 3 ]curcumin, [ 13 C 5 ]curcumin, and [d 6 ]bicyclopentadione, the major oxidative metabolite of curcumin. We also describe synthesis of the labeled building blocks [ 14 C]vanillin, [d 3 ]vanillin, and [ 13 C 5 ]acetylacetone. The overall molar yields of the labeled products were 52 ([ 14 C]) and 47% ([d 3 ]) for vanillin and 25 ([ 14 C 2 ]) and 27% ([d 6 ]) for curcumin. The compounds can be used as radiotracers in biotransformation studies and as isotopic standards for mass spectrometry‐based quantification in pharmacokinetic analyses. Copyright © 2013 John Wiley & Sons, Ltd.