Rapid Synthesis of Curcuminoid Pyrazoles with Antiviral Effects Through One-Pot Combinatorial Modification of Total Curcuminoids

Four new curcuminoid pyrazoles (1-4) were synthesized by one-pot combinatorial modification of the total curcuminoid extract, through chemical transformation of β-diketone functionalities by p-chlorophenylhydrazine. All four curcuminoid pyrazoles were identified by spectroscopic methods, and the structure of compound 4 was further confirmed by single-crystal X-ray analysis. Compounds 1 and 2, with a long conjugated system and at least one methoxy substitution, showed a more potent antiviral effect than did the corresponding natural product, curcumin. The rapid synthesis of curcuminoid pyrazoles with improved antiviral activity high- lights the great potential of one-pot combinatorial modification for the diversification of natural products with improved bioactivities. Keyword: curcumin, one-pot combinatorial modification, antiviral