Demethoxycurcumin: a potential antimicrobial agent.

Demethoxycurcumin (DMC) is one of the major constituents in Curcuma longa L., and it is safe at a large dose range. In this study, the antimicrobial activity of DMC on Escherichia coli, Staphylococcus aureus, and Shigella dysenteriae was investigated by microcalorimetry and modified broth microdilution. Minimal inhibitory concentration and 50 % inhibiting concentration were determined by modified broth microdilution, which was fast and economical. Thermokinetic parameters were extracted from the heat-output power curves delineated by microcalorimetry, which was accurate and dynamic, and the multiple parameters were analyzed by similarity analysis and principle component analysis. The results demonstrated that DMC presented good antimicrobial activity, and the sequence of activity was as follows: E. coli > S. aureus > S. dysenteriae. This study provides a useful methodology for the determination of antimicrobial activity of natural products. In addition, it provides the foundation for the exploitation of DMC as a potential antimicrobial prodrug. [ABSTRACT FROM AUTHOR]