ANTI-INFLAMMATORY AND ANTIOXIDANT ACTIVITY OF SYNTHESIZED MANNICH BASE DERIVATIVES OF (2E,6E)-2-[(4-HYDROXY-3-METHOXYPHENYL)METHYLIDENE]-6-(PHENYL METHYLIDENE)CYCLOHEXAN-1-ONE

Objective: To further understand this compound, we synthesized and evaluated the antioxidant and anti-inflammatory activity of a series of itsMannich base derivatives.Methods: We synthesized the compounds via the previously reported Mannich reaction method. Their structures were elucidated by Fouriertransforminfrared,1H-NMR,13C-NMR, and high-resolution mass spectra. The derivatives’ anti-inflammatory and antioxidant activities were testedusing the inhibition of protein denaturation method and the 2,2-diphenyl-2-picrylhydrazyl free radical scavenging assay.Results: The IC50 values for the anti-inflammatory activity of the 2,6-dimethylmorpholine, pyrrolidine, 1-methylpiperazine, and dimethylamineMannich base derivatives 2a–d were 10.67, 10.72, 37.75, and 1.93 μM, respectively; for (2E,6E)-2-({4-hydroxy-3-methoxyphenyl}methylidene)-6-(phenylmethylidene)cyclohexan-1-one (1), diclofenac sodium, and curcumin, the IC50 values were 56.29, 1.52, and 8.43 μM, respectively. The IC50values for the antioxidant activity of compounds 2a–2d were 229.62, 57.29, 280.43, and 219.22 μM, respectively; for compound 1, quercetin, andcurcumin, the IC50 values were 144.22, 27.28, and 26.45 μM, respectively.Conclusion: Substituting Mannich bases into (2E,6E)-2-[(4-hydroxy-3-methoxyphenyl) methylidene]-6-(phenylmethylidene)cyclohexan-1-oneenhanced its anti-inflammatory activity, but lowered its antioxidant activity. Compound 2d, (2E,6E)-2-({3-[(dimethylamino)methyl]-4-hydroxy-5-methoxyphenyl}methylidene)-6-(phenyl methylidene)cyclohexan-1-one, exhibited potent anti-inflammatory activity comparable to diclofenacsodium and four times higher than curcumin. However, further investigation of this compound’s mechanism of action and toxicity is warranted