Synthesis and in vitro Antioxidant Activity Study of Some Novel Substituted Piperazinyl Flavone Compounds

摘要

Background: A new series of 13 piperazinyl flavone derivatives has been synthesizedand examined for their in vitro antiradical and antioxidant activities in response to the pharmacyindustry’s increasing demand for new non-toxic anti-inflammatory and anticancer drugs.Method: Their antioxidant activity was evaluated by the reactive oxygen species (ROS) scavengingassays, 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH?) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS+?) scavenging assays, and the ferricreducing antioxidant potency (TAC) method, and was compared to known positive controls, herbalinfusions, and penicillins. Chemiluminescence, spectrophotometry, electron spin resonance (ESR)and 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) as the spin trap were the measurement techniques.Result: It was seen that synthesized compounds have a wide spectrum of antioxidant property.Some of the test compounds proved to be extremely efficient scavengers of H2O2 exhibiting, insome cases, EC50 of about 2 μM. The values of antioxidant status (TAS) were in the range of 49 ±3.9 to 1283 ± 51.3 μM TE/g (TE = Trolox equivalent) and were lower than that of butylated hydroxytoluene(BHT) (1304 ± 43.2 μM TE/g) and green tea (1356 ± 40.0 μM TE/g), but for severalsynthesized compounds, they were higher than chamomille infusion and penicillins. Ferric reducingantioxidant powers (TAC) for the piperazinyl flavone derivatives were in the range 7 ± 0.5 to104 ± 0.6 μM TE/g and were weaker than that of BHT (217 ± 5.3 μM TR/g ).Conclusion: Carboxylic or hydroxamic acid substituted piperazinyl flavones are potentially activeas antioxidants, thus may be suggested as pharmacologically interesting ones.