New 3-acyl derivatives of glaucocalyxin A: designed, synthesis and <i>in vitro</i> antibacterial activities

To discover novel antimicrobial drug, 22 novel acylated derivatives were synthesized by A-ring modification of glaucocalyxin A. The structures of these derivatives were confirmed by NMR and MS data. <i>In vitro</i> antimicrobial activity of these compounds was evaluated against <i>E. faecium</i>, <i>E. faecalis</i>, MRSA, <i>E. coli</i>, <i>A. baumannii</i> and <i>K. pneumoniae</i>. The results showed compound <b>3d</b> against <i>E. faecium</i>, <i>E. faecalis</i> and MRSA with a minimum inhibitory concentration of 4 μg/ml. And further molecular docking revealed that compound <b>3d</b> has a higher binding affinity. In conclusion, compound <b>3d</b> has the potential to develop into a new drug against drug-resistant bacteria.