Synthesis and studies of flavone and bis-flavone derivatives

Abstract

Flavonoids are widely occurring polyphenols of plant origin and well explored in the field of pharmacological activities. Recent studies showed this scaffold to be more dynamic as fluorescent probe. Very rare reports are there in literature on flavones as liquid crystals, for the first time we have synthesized and characterized flavone and bis-flavone derivatives for mesomorphic properties. Compounds 9a–d and 13a–d were studied for liquid crystalline properties by Differential scanning calorimetry (DSC) and Polarizing optical microscopy (POM) studies. The compounds 8, 9a–d, 12, and 13a–d were also studied for antioxidant property by DPPH assay.

Graphical abstract

We have synthesized new n-alkoxy flavone and Bis-flavone derivatives for liquid crystalline properties. The compounds were characterized by using different spectral techniques, all synthesized compounds did not show mesophase which was confirmed by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) study. POM image of compound 9c in heating (a) shows direct melting (92.2°C) of compound and cooling (b) goes to crystallization (65.8°C) with no phase. Flavone derivatives are well reported to show broad pharmacological applications, we have also tested compounds for antioxidant properties by DPPH assay.

Keywords:

• Antioxidant activity
• bis-flavones
• flavones
• liquid crystals
• synthesis

Acknowledgment

Authors are thankful to Head department of chemistry and department of Zoology, faculty of science, The Maharaja Sayajirao University of Baroda for laboratory facilities. DST-FIST for NMR facility in the department.