Synthesis, Characterization, and Biological Studies of Novel 4-Hydroxy-6-methyl-5,6-dihydro-2H-pyran-2-one Based Azo Dyes

Objective: Due to wide range of biological activities exhibited by pyran derivatives such as antibacterial, antioxidant, anticancer and other activities, we have synthesized and investigated the biological activity of some pyran derivatives. Methods: A series of 4-hydroxy-6-methyl-5,6-dihydro-2H-pyran-2-one based azo dyes (IIIa–IIIf) have been synthesized by a conventional diazo coupling reaction. The antioxidant activity was determined via DPPH assay and Antimicrobial activity through disc diffusion test. Results and Discussion: Compound (IIIb) has shown excellent radical scavenging activity with an IC₅₀ value of 20.22 ± 7.36 µg/mL compared to the standard. Furthermore, compounds (IIIc) and (IIId) showed a good antibacterial and antifungal activity against Escherichia coli and Aspergillus niger compared to other prepared azo compounds. Conclusions: We propose that in future, synthesized compounds may act as a promising antimicrobial drugs.