Synthesis of novel chalcone derivatives by conventional and microwave irradiation methods and their pharmacological activities

AbstractChalcones are abundant in edible plants and are considered to be the precursors of flavonoids and isoflavonoids. Chalcones belong to an important class of flavonoids, which may be prepared by Claisen–Schmidt condensation. They possess a wide range of biological activities and industrial applications. The cytotoxicity against tumour cell lines may be the result of disruption of the cell cycle, inhibition of angiogenesis, interference with p53-MDM2 interaction, mitochondrial uncoupling or induction of apoptosis. Chalcones are synthesized by conventional and microwave assisted synthesis methods. By microwave assisted synthesis, a considerable increase in the reaction rate has been observed and that too, with better yields. The compounds have been screened for cytotoxic activity and antioxidant activity

A comparative study on synthesis of some novel α,β-unsaturated carbonyl derivatives and their antioxidant potential

Free radicals are constantly formed in human system either as accidental products during metabolism or deliberately during the process of phagocytosis or due to environmental pollutants, ionizing radiations, ozone, heavy metal poisoning, etc. It is found from literature survey that chalcones (α,β-unsaturated carbonyl derivatives) exhibit great antioxidant activity. Hence, the synthesis of some new chalcone derivatives was undertaken and were synthesized by two methods namely, conventional and microwave irradiation methods. The synthesized chalcone derivatives were tested for their in vitro antioxidant activity by using NBT-superoxide free-radical scavenging activity and DPPH radical scavenging activity. The potency of the chalcone derivatives was estimated by IC50 values and they have shown promising antioxidant activity. Among all the chalcones synthesized, derivative 3e showed maximum superoxide inhibition as per NBT method and all the derivatives have shown different percentage inhibitions at different concentrations as per  DPPH method. The compounds were characterized by 1H NMR and IR spectral analysis

Ruthenium nanoparticles embedded poly(4-aminodiphenylamine) nanocomposites based determination of guaifenesin in real samples

An efficient sensing surface is fabricated through incorporating ruthenium on electropolymerized poly-(4-aminodiphenylamine)(Padpa) film by potentiodynamic cycling of 4-aminodiphenylamine (4-adpa) in an acidic medium. The mechanism of electropolymerization comprises the conversion of protonated monomer to di-imine species and generates positively charged radical-intermediate via dimerization step. The surface morphology of deposited film on electrode surface is studied using SEM and XPS techniques. The electrocatalytic appraisal of constructed (Ru/Padpa/GCE) sensing interface is examined towards the electro-oxidation of guaifenesin (GUA) by differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), and chronoamperometric (CA) methods. The Ru/Padpa/GCE sensing interface displayed a linear response of GUA from 1.5 to 45 µg/mL with the limit of detection (LOD) of 48.8 ng/mL (S/N = 3). The obtained higher activity of Ru/Padpa/GCE is mainly attributed to its larger active surface area, faster electron transfer kinetics, and higher catalytic sites from the interface. The Ru/Padpa/GCE sensing interface is further applied for the determination of GUA in pharmaceutical (cough syrup, and human urine) samples with a recovery of 97.1–101.0 %. The diffusion coefficient of GUA (1.51 × 10-6 cm2/s) is also obtained via theoretical electrochemical method, which ensures that Ru/Padpa/GCE sensing interface can be considered as a potential candidate for clinical diagnostic analysis

Conventional and microwave assisted synthesis of 2-amino-4,6-diaryl pyrimidine derivatives and their cytotoxic, anti-oxidant activities

Pyrimidine is the parent substance of a large group of heterocyclic compounds and plays a vital role in many biological processes. It is also evident from literature; pyrimidines possess potential anti oxidant activities and cytotoxic activities. Chemoprotection by pyrimidines may be a consequence of their antioxidant properties, mediated via inhibition or induction of metabolic enzymes, by an anti-invasive effect or a reduction in nitric oxide production.  Free radicals are formed constantly in human system either as accidental products during metabolism or deliberately during the process of phagocytosis; or due to environmental pollutants, ionizing radiations, ozone, heavy metal poisoning, etc. Therefore, it is worthwhile to synthesize some pyrimidine derivatives by conventional and microwave (Catalyst systems) assisted synthesis methods. The synthesized compounds were purified by recrystallization or by chromatography and are characterized by 1H NMR, 13C NMR and IR analysis. The compounds were tested for their potential cytotoxic activity and antioxidant activities by standard methods. The microwave irradiation method (MWI) is proved to be advantageous with considerable increase in the reaction rate with better yields, after over all observation it is found  that pyrimidine derivatives possessing cytotoxic and anti-oxidant activities