Synthesis, antioxidant and antimicrobial evaluation of simple aromatic esters of ferulic acid.

Aromatic ester derivatives of ferulic acid where the phenolic hydroxyl is free (6a-d) or acetylated (5a-d) were evaluated for their antioxidant and antimicrobial properties. The superoxide radical scavenging capacity of compounds 5d and 6d-e (IC(50) of 0.19, 0.27 and 0.20 mM, respectively) was found to be twice as active as α-tocopherol (IC(50) = 0.51 mM). DPPH radical scavenging capacity was moderate and only found in compounds bearing free phenolic hydroxyl groups (6a-e). With regard to antimicrobial properties, compounds 6b and 6c displayed significant activity against Enterococcus faecalis (MICs = 16 µg/mL) and vancomycin-resistant E. faecalis (MIC for 6b, 32 and for 6c, 16 µg/mL). Compound 6c also demonstrated prominent activity against planktonic Staphylococcus aureus with a MIC value of <8 µg/mL and it inhibited bacterial biofilm formation by S. aureus with a MBEC value of <8 µg/mL, which was 64 and 128 times more potent than ofloxacin and vancomycin, respectively.

Synthesis of 1,5-diarylpyrazol-3-propanoic acids towards inhibition of cyclooxygenase-1/2 activity and 5-lipoxygenase-mediated LTB4 formation.

A set of 25 derivatives of 3-[1-(6-substituted-pyridazin-3-yl)-5-(4-substituted-phenyl)-1H-pyrazol-3-yl]propanoic acids has been synthesized and evaluated for their in vitro cyclooxygenase-1/2 (COX-1/ 2) inhibitory activity using assays with purified COX-1 and COX-2 enzymes as well as for their 5-lipoxygenase (5-LO)-mediated LTB4 formation inhibitory activity using an assay with activated human polymorphonuclear leukocytes (PMNL). Among the synthesized compounds, especially 4g showed COX-1 (IC50 = 1.5 microM) and COX-2 (IC50 = 1.6 microM) inhibitory activity, whereas compounds 4 b and 4 f resulted in the inhibition of 5-LO-mediated LTB4 formation at 14 microM and 12 microM IC50 values, respectively, without any significant inhibition on COX isoforms.