Synthesis and Biological Evaluation of Andrographolide Derivatives as Potent Antibacterial Agents

A series of andrographolide (Andro) derivatives (3-14) were designed, synthesized and screened for their antibacterial activities against both gram-positive and gram-negative bacteria in vitro. The most promising compounds 14a-c exhibited at least eight-fold stronger antibacterial activities compared to Andro. Especially, Compound 14a, which showed 32-fold stronger antibacterial activity than Andro, has a potency to be a new lead. Keywords: Andrographolide, Antibacterial activity, Derivatives, Lactone, P. aeruginosa, Synthesis, bicyclic diterpenoid lactone, Andrographis paniculata, gram-negative bacteria, Elemental analysis, Shimadzu FTIR-8400S spectrometer, TMS standard, MSD spectrometer, LC spectrometer, halohydrocarbon, epigenetics