Synthesis of thiazolylidenethiazoloquinazolinone hybrids from monocarbonyl curcumin analogues. Characterization, bio-evaluation and DFT study

Abstract

Given the diverse pharmacological attributes possessed by the curcumin and its analogs, quinazolinethione 3, thiazoloquinazolinone 4, and thiazolylidene thiazoloquinazolinone hybrids D1-D12 were synthesized from α, α’ Bis(arylidene)Cyclohexanone (BAC) as starting material. The proposed structures of all synthesized compounds were confirmed by ¹H, ¹³CNMR, and elemental analysis. The newly synthesized hybrids were screened in vitro for their antimicrobial and antioxidant activities. Preliminary studies showed that compounds D4, D5, D10, D11, and D12 exhibited superior inhibitory behaviors against some microorganisms in comparison with standard drugs. In addition, DPPH radical scavenging assay was used to evaluate their antioxidant property. Accordingly, compound D11 was found to be a more powerful antioxidant than the other compounds. Furthermore, the HOMO–LUMO energy values and some chemical parameters indicate that the synthesized hybrid D11 is more reactive than D7. These results were consistent with our experimental data on antioxidants. Moreover, molecular electrostatic potential (MEP) maps were computed in order to predict the reactive sites for nucleophilic and electrophilic attacks of the synthesized hybrids D7 and D11.

GRAPHICAL ABSTRACT

KEYWORDS:

• Curcumin hybrids
• Thiazole
• Biology
• DFT

Acknowledgments

The authors are grateful to Professor Gilbert Kirsch, Lorraine University and his group for RMN and elementary analyses. The authors acknowledge the directorate general for scientific research and technological development (DGRSDT, Algeria), the thematic research agency in science and technology (ATRST, Algeria) for the financial support of this research work.

Disclosure statement

No potential conflict of interest was reported by the author(s).