2'-Hydroxy-3,4,4',6'-tetramethoxychalcone (Compound 5) has antibacterial activity, with a MIC value of 10 μg/mL for E. coli and S. epidermis. 2'-Hydroxy-3,4,4',6'-tetramethoxychalcone can be isolated from Piper obliquum[1].
References
[1] Valdivia C, et al. Bioactive alkenylphenols from Piper obliquum. Bioorg Med Chem. 2008 Apr 1;16(7):4120-6. DOI:10.1016/j.bmc.2008.01.018