Priebe A, et al. - In view of the observation that incarvillateine (INCA), derived from the Chinese herb Incarvillea sinensis, has its primary antinociceptive action through the adenosine receptor, a novel pain target, researchers investigated if derivatives of cinnamic acid dimers, which are structurally similar to INCA, would show potent antinociceptive action and if their effect would be mediated through adenosine receptor action. Using cavitand-mediated photodimerization (CMP) method, they synthesized dimers of cinnamic acid (INCA analogs). Ferulic acid dimer, which has the same chemical functionalities on the aromatic ring as INCA, demonstrated potent nonopioid antinociceptive action mediated predominantly through A3AR – adenosine 3 receptor action.