Methoxychalcones: Antimicrobial and Antiproliferative Activities

Methoxychalcones have presented antimicrobial and antiproliferative bioactivities.1,2 However, a clear investigation about methoxyl relevance on chalcone framework has not been described. This work aimed the synthesis and bioactivity evaluations of 17 regioisomeric methoxychalcones, constituted by methoxy groups on rings A (5–12) and B (13–21). Methoxychalcones were synthesized by Claisen-Schmidt3 reaction and were evaluated for against five Candida species, two Gram-negative and two Gram-positive bacteria. For antiproliferative activity, methoxychalcones were evaluated against four human tumorigenic cell lines, as well as human non-tumorigenic keratinocytes. Chalcones containing methoxy groups on ring A were the most antifungal, antibacterial and antiproliferative agents. 3’,4’,5’-trimethoxychalcone (12) demonstrated antifungal activity against Candida krusei (MIC = 3.9 µg/mL), 3’-methoxychalcone (6) displayed anti-Pseudomonas activity (MIC = 7.8 µg/mL), 2’,5’-dimethoxychalcone (9) exhibited antiproliferative effect against C-33A (skin), A-431 (skin) and MCF-7 (breast), with IC50 values ranging from 7.7 to 9.2 µM.