BackgroundThe quinazoline are an important class of medicinal compounds that possess a number of biological activities like anticancer, anticonvulsant and antioxidant etc.ResultsWe evaluated the previously synthesized quinazoline derivatives 1–3 for their anticancer activities against three cancer cell lines (HepG2, MCF-7, and HCT-116). Among the tested compounds, quinazolines 1 and 3 were found to be more potent than the standard drug Vinblastine against HepG2 and MCF-7 cell lines. All the tested compounds had less antioxidant activity and did not exhibit any anticonvulsant activity. Also, molecular docking studies were performed to get an insight into the binding modes of the compounds with human cyclin-dependent kinase 2, butyrylcholinesterase enzyme, human gamma-aminobutyric acid receptor. These compounds showed better docking properties with the CDK2 as compared to the other two enzymes.ConclusionsThe overall study showed that thioxoquinazolines are suitable antitumor agents and they should be explored for other biological activities. Modification in the available lot of quinazoline and synthesis of its novel derivatives is essential to explore the potential of this class of compounds. The increase in the threat and with the emergence of drug resistance, it is important to explore and develop more efficacious drugs.

Quinazolinone derivatives have been reported to show a variety of biological properties, such as antimicrobial 1-6 , anticonvulsant 7-10 , antitumor 11-16 , anticoccidial 17 , antidepressant 18 , antihistaminic 19,20 , antiinflammatory 21-24 and antiviral 25,26 activities. Febrifugine and its analogue have been used as an anti malarial treatment 27-29. In addition, many thioxoquinazolin-4(3H)-one derivatives exhibit a considerable variety of activities, such as anticonvulsant 30 , anticancer 31,32 , antiulcer 33 and antiinflammatory and have been used as therapeutic agents for neuro-protection 34. Some novel thioxoquinazolinone derivatives have been synthesized using three different methods i.e., conventional synthesis, ultrasonic and microwave irradiation. The structures of these compounds were firmly established by well-defined IR, 1 H NMR, 13 C NMR, 2D NMR and ESI-MS spectroscopies. These compounds were then examined for antibacterial properties. EXPERIMENTAL The melting points (m.p.) were determined using an Electrothermal IA900 digital capillary melting point apparatus. The IR spectra were recorded in KBr discs on a Perkin Elmer 1000 FT-IR spectrophotometer (νmax in cm-1). The 1 H NMR, 13 C NMR spectra and 2D NMR spectra were collected in DMSO-d6 or (CDCl3) using a JEOL-ECP-400 and on Bruker 600 MHz spectrometer. The chemical shifts were reported as parts per million (δ ppm) and the coupling constants (J) are given in Hz,