Synthesis of curcumin oligomers

Abstract

Bis(4-((1E,6E)-7-(2-methoxyphenyl)-3,5-dioxohepta-1,6-dienyl)-2-methoxy phenyl) succinate (curcumin oligomer) was synthesized from 1,7-bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione (curcumin) and succinic acid through esterification using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDCI) and 1-hydroxy-benzotriazole (HOBt) as coupling agents. Then, bis(4-((1E,6E)-7-(3,4-dimethoxyphenyl)-4-methyl-3,5-dioxohepta-1,6-dienyl)-2-methoxyphenyl) succinate (MCO) was synthesized by nucleophilic substitution reaction from curcumin oligomer and methyl iodide. MCO possesses UVA absorption property. MCO is soluble in most organic solvent such as diethyl ether, dichloromethane, chloroform and acetone. Ex vivo skin penetration test using baby mouse skin (Mus Musculus Linn.) of MCO showed that the oligomer could not penetrate through the baby mouse skin.