Synthesis of (±)‐Pisonivanone and Other Analogs as Potent Antituberculosis Agents

A new class of alkylated chalcones and flavanones was synthesised and screened for antituberculosis, antixoidant, and cytotoxic activities. The desired compounds were synthesised using methyl substituted 2‐hydroxyacetophenone as a key intermediate. The acetophenone derivative having methyl substitution was prepared in turn from methtylated phloroglucinol by formylation (by Vilsmeier‐Haack reaction), followed by reduction with Wolf‐Kishnner approach, and finally acetylation was involved. Among 17 compounds, compound 5 and compound 4a inhibited M. tuberculosis at minimum inhibitory concentration (MIC) in the range between 25 μg/mL and 50 μg/mL. The remaining other 15 compounds also potently inhibited M. tuberculosis at MIC in range between 50 μg/mL and 100 μg/mL. Some of these compounds also showed moderate antioxidant and cytotoxic activities.