Antibacterial Activity of Methyl Cinnamate, Cinnamic Acid and Cinnamic Acid Derivatives Derived from Alpinia malaccensis Rhizomes

Alpinia malaccensis L. contains the largest phytochemical component, methyl cinnamate. The base hydrolysis of methyl cinnamate resulted cinnamic acid compound. In this study, were carried out isolation of methyl cinnamate, hydrolysis of methyl cinnamate into cinnamic acid and modification cinnamic acid through esterification, amidation, and substitution on the benzene ring. The synthesized compounds were characterized using 1H-NMR and 13C-NMR. The ester of 2-methoxyphenyl cinnamate, the amide of 1-cinnamoylpyrrolidine and methyl-4-nitro cinnamate, as well as methyl-2-nitro cinnamate were identified. These compounds were tested for antibacterial activity against five bacterial strains: E. coli, P. aeruginosa, B. substilis, S. aureus, and MRSA. The antibacterial activity test determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the characterised compounds. Compound 1-cinnamoylpyrrolidine exhibited the strongest MIC and MBC values of 0.5 mg/mL against all bacterial strains.