Synthesis and structure of new heterocyclic derivatives of curcumin

摘要

New heterocyclic derivatives of curcumin(3)of different ring size were synthesized by reaction of a key intermediate,l,7-bis(4-acetoxy-3-methoxyphenyl)hepta-3,5-dione(5)with some bi-nucleophilic molecules.These new synthetic derivatives were obtained in good yields and the structure of all compounds was supported by MS,IR,ID and 2D ~1H and ~I3C NMR spectra and elemental analysis.Curcumin,5-hydroxy-l,7-bis(4-hydroxy-3-methoxyphenyl)hepta-l,4,6-trien-3-one(3)is a secondary metabolite and the main yellow compound of Curcuma longa rhizomes(Figure 1).It is present together with 5-hydroxy-l-(4-hydroxy-3-methoxyphenyl)-7-(4-hydroxyphenyl)hepta-1,4,6-trien-3-one(demetho-xycurcumin,2),and 5-hydroxy-l,7-bis(4-hydroxyphenyl)hepta-l,4,6-trien-3-one(bisdemethoxycurcu-min,1)in curcuma powder(turmeric),which is the main component of curry powder,a widely used seasoning.The use of Curcuma in traditional medicine is widespread in several parts of Asia,but it has also been extended to other continents.