Synthesis of 2-Substituted 4-Arylidene-5(4H)-oxazolones as Potential Cytotoxic Agents in the Presence of Lemon Juice as a Biocatalyst

Background: The oxazolone class of compounds is known to exert a profound effect on malignant cell proliferation, tumor angiogenesis and /or on the established neoplastic vasculature. Additionally, these compounds are generally known to have a low tendency to interact with DNA which is not common with most of the conventional cytotoxic agents. Thus, this class of compounds is of particular interest for the discovery and development of patient-friendly anticancer agents. Objective: The initial objective of this study was to synthesize and evaluate 2-substituted 4-arylidene- 5(4H)-oxazolones for their potential anticancer properties. Methods: A simple, mild and non-hazardous synthetic methodology has been developed for the preparation of 2-substituted 4-arylidene-5(4H)-oxazolones. The methodology involved lemon juice mediated condensation of N-acyl glycine derivatives including hippuric acid with arylaldehydes in PEG-400 under ultrasound irradiation. All the synthesized compounds were screened via an MTT assay for their potential cytotoxic properties in vitro using the cancerous cell lines e.g. K562 (human chronic myeloid leukemia), Colo-205 (human colon carcinoma), and A549 (human lung carcinoma) and a non-cancerous HEK293 (human embryonic kidney) cell line. Results: Compounds 3a, 3c and 3i showed promising growth inhibition against A549 cell line but no significant effects on HEK293 cell line, indicating their selectivity towards cancer cells. Moreover, their IC50 values suggested that all these compounds were comparable to the reference drug doxorubicin indicating their potential against lung cancer. Conclusion: The 4-arylidene-5(4H)-oxazolone framework presented here could be a new template for the design and discovery of potential anticancer agents especially for lung cancer.