Abstract

Background: Chalcones, natural products produced by plants as a natural defense mechanisms against various pathogens, are molecules with structures that include two aromatic rings joined by an α, β unsaturated carbonyl system. Previous research has demonstrated that chalcones exhibit a wide variety of biological activities, including anticancer, antifungal, and antibiotic properties.

Objective: Our goal is to synthesize novel heterocyclic-containing chalcones and have their biological activities evaluated.

Methods Sixteen chalcones were synthesized by the crossed aldol condensation of substituted tetralones with substituted pyridinylaldehydes. The products were purified by recrystallization in MeOH/H2O and characterized by 1H NMR, 13C NMR, and HRMS. Anticancer assays were performed by NCI (National Cancer Institute) against the NCI-60 panel of 60 different human cancer cell lines, including leukemia, non-small-cell lung cancer, colon, central nervous system, melanoma, ovarian, renal, prostate, and breast cancer. Antimicrobial assays were performed by COADD (Community for Open Antimicrobial Drug Discovery) against Escherichia coli, Klebsiella pneumonia, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus, Cryptococcus neoformans var. grubii, and Candida albicans.

Result: Chalcone 3d had demonstrated growth inhibition greater than 60% against a variety of cancers: leukemia (MOLT-4, SR), non-small cell lung cancer (NCI-H522), colon cancer (HCT- 116), prostate cancer (DU-145), and breast cancer (MCF7, MDA-MB-468) and was also cytotoxic to three different cell lines (CCRF-CEM, RPMI-8226, and KM12). 5c was active against leukemia (CCRF-CEM, RPMI-8226, SR) and breast cancer (MCF7) and 5e was active only against leukemia (RPMI-8226, SR). 5h was partially active and the best compound with growth inhibition of MRSA by 75%. 3b was the best compound against EC, KP, and PA and 3f had the greatest activity against AB. For fungi, 3f and 3e demonstrated the best growth inhibition.

Conclusion: A small library of heterocyclic-containing chalcones was developed and initial screening demonstrates modest activity against cancers, bacteria, and fungi.

Keywords: Aldol condensation, antibacterial, anticancer, chalcones, pyridine, tetralone.

Graphical Abstract