Coumarins are important and useful compounds with diverse pharmacological properties. New coumarin derivatives namely N-aminoquinoline-2-one 1, 1-((4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)methyleneamino)quinolin-2(1H)-one 2 and 1,1 0 -(1E,1 0 E)-(1,4-phenylenebis(methan-1-yl-1-ylidene))bis(azan-1-yl-1-ylidene)diquinolin-2(1H)-one 3, were synthesized and characterized by UV-Vis, FT-IR, and NMR spectra in addition of elemental analysis. The synthesized compounds (2 and 3) show considerable anticancer activity against HEp-2 cell line. Synthesized compounds (2 and 3) were tested against selected types of microbial organisms and showed significant activities. The free-radical scavenging activity of synthesized compounds (2 and 3) have been determined by their interaction with the stable freeradical 1,1-diphenyl-2-picrilhydrazyl (DPPH) and all the compounds have shown encouraging antioxidant activities.

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Background: Coumarin is quite extend in plants including various vegetables, flavors, foods. Coumarin has various significant medicinal activities such as anti-inflammatory, anti-oxidant, anti-viral, anti-microbial, anti-cancer and has been indicated to increase central nervous system activity. Methods: The syntheses of tailor-made coumarins, which are highly compelling for medical applications due to their structurally interesting antioxidant activity, were report in this manuscript. Coumarins were synthesized successfully through the modification of 4-hydroxycoumarin by different reaction steps. The molecular structures of the coumarins were characterized by the Fourier transformation infrared and Nuclear magnetic resonance (NMR) spectroscopies. The antioxidant efficiency of the 4-hydroxycoumarins were evaluated by typical spectroscopic method, using radicals DPPH• and H 2 O 2 . Results: The new coumarins synthesized in this work exhibited an excellent antioxidant compared to the free vitamin C. Molecular modelling studies using DFT (Density Functional Theory) calculations showed that there is a high correlation between dipole moment, Ionization potential (IP), Electron affinity (EA), Hardness (η), Softness (S), Electro negativity (µ), energy gap, HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular) energies and antioxidant activity. Conclusion: New coumarin derivatives were successfully synthesized using chemical methods. The characterized of these coumarins were done by using different spectroscopic techniques (FT-IR and NMR) and micro-elemental analysis (CHNS). The antioxidant activity of these coumarins were determined by using DPPH and hydrogen peroxide assays. Results indicated that the new coumarins possess higher scavenging activity than vitamin C.

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Problem statement: Pyridones are known to have variety of biological activities like antitumor, antibacterial, antiinflamatory and antimalarial activities. This study presented antitumor evaluation of dihydropyridones derived from curcumin, as well as curcumin for comparison. Approach: The compounds evaluated for a preliminary estimation of the in vitro tumor inhibiting activity against 11 of tumor cell lines by using Microculture Tetrazolium assay (MTT) method. The method is based on the metabolic reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. The cell lines of tumor subpanels were incubated within five concentrations (0.01-100 µg mL^-1) of each tested compound for 48 h. Results: Antitumor biological activities represented as CC₅₀ were within the range >100-17±1 against leukaemia (MT4). The CC₅₀ values were found to increase with increasing chain length of the substituent on the nitrogen atom. Conclusion: Antitumor activities of the tested dihydropyridones can be enhanced by increasing chain length of the substituent on the nitrogen atom