Synthesis and In Vitro Antibacterial Activity of Quaternized 10-Methoxycanthin-6-one Derivatives.

BACKGROUND

Based on our previous work, we found that 10-methoxycanthin-6-one displayed potential antibacterial activity and quaternization was an available method for increasing the antibacterial activity. Here, we explored the antibacterial activity of quaternized 10-methoxy canthin-6-one derivatives.

METHODS AND RESULTS

Twenty-two new 3--benzylated 10-methoxy canthin-6-ones were designed and synthesized through quaternization reaction. The in vitro antibacterial activity against three bacteria was evaluated by the double dilution method. Moreover, the structure-activity relationships (SARs) were carefully summarized in order to guide the development of antibacterial canthin-6-one agents. Two highly active compounds ( and ) displayed 8-fold superiority (MIC = 3.91 µg/mL) against agricultural pathogenic bacteria and compared to agrochemical streptomycin sulfate, and showed potential activity against . Moreover, these two compounds exhibited good "drug-like" properties, low cytotoxicity, and no inhibition on seed germination.

CONCLUSIONS

This work provides two new effective quaternized canthin-6-one derivatives as candidate bactericide, promoting the development of natural-sourced bactericides and preservatives.