Novel 1,3-Indenedione-Based Azo Dyes: Synthesis, Characterization, Solvatochromic UV-Vis Absorption Study, and Biological Activity

In this work, we reported the synthesis of novel indanedione-based azo dyes by a conventional diazo coupling reaction at 0–5°C. The synthesized dyes were characterized by using different spectroscopic techniques like FT-IR, 1 H NMR and HRMS. The indanedione-based azo dyes were examined for cytotoxic activity against MIAPaCa-2 pancreatic cancer cell lines. 2-[( E )-1,3-Benzothiazol-2-yldiazenyl]-1 H -indene-1,3(2 H )-dione showed a good reduction in cell viability against MIAPaCa-2 cell line in a concentration dependent manner compared to other compounds. Further, the synthesized azo dyes were screened for DPPH radical scavenging activity in which 2-[( E )-1,3-thiazol-2-yldiazenyl]-1 H -indene-1,3(2 H )-dione, 2-[( E )-(6-ethoxy-1,3-benzothiazol-2-yl)diazenyl]-1 H -indene-1,3(2 H )-dione, and 2-[( E )-(4-nitrophenyl)diazenyl]-1 H -indene-1,3(2 H )-dione showed good scavenging activity with IC 50 values of 116.68±1.2, 20.73±7.54 and 129.49±34.25 µg/mL when compared to standard. Furthermore, synthesized indanedione-based azo dyes exhibited appreciable binding affinity with the HIF-1 receptor. Among the synthesized compounds, 2-[( E )-(4-nitrophenyl)diazenyl]-1 H -indene-1,3(2 H )-dione exhibited a higher binding affinity (–8.9 kcal/mol) by establishing two hydrogen bonds.