Structure-function activity of dehydrozingerone and its derivatives as antioxidant and antimicrobial compounds.

Dehydrozingerone, structural half analogue of curcumin, is a phenolic compound isolated from ginger (Zingiber officinale) rhizomes. Dehydrozingerone and several of its derivatives such as glucopyranosides and its tetra acetate derivative and 4-O-acetyl and methyl derivatives of dehydrozingerone were synthesized in the present study. Dehydrozingerone, synthesised with improved yield was used for the synthesis of Dehydrozingerone 4-O-β-D-glucopyranoside (first time report) by modified Koenigs-Knorr-Zemplén method. Structures of all the compounds have been established using spectroscopic methods. These compounds were tested for radical scavenging activity by DPPH and FRAP method as well as for antibacterial and antifungal activities. The parent molecule exhibited better scavenging activity as compared to its derivatives indicating the significance of free phenolic hydroxyl group. Also, Dehydrozingerone and its derivatives exhibited antibacterial as well as antifungal activity due to the conjugation system present, which includes α,β-unsaturated carbonyl (C = O) group. This study gave an insight into structural requirements for dehydrozingerone activity.