Background: The study of free radicals nowadays have become more attention as these are evoked continuously due to hazardous environmental conditions and food habits. Endogenously free radicals are introduced in our body due to exposure to different physiochemical conditions or some pathological states by various mechanisms. Oxidative stress occurs due to exposure of excess free radicals to body. Antioxidants act as a major defence against the free radical-mediated injury by scavenging them. Majority of the flavonoids found in plant products are known as antioxidants as they selectively scavenge the free radicals. Methods: Synthetic flavones (VMF41, VMF 43, VMF 45 and VMF 46) having different side chains on the: 3-hydroxy-2- (5-methyl, 7-methyl, 6-methyl, and 7--methoxy) 2- thiophen-4H-chromen-4-one structure were examined for free radical scavenging potential over nitric oxide, hydroxyl, and superoxide anion radicals by using appropriate in-vitro assay methods. Results and Discussion: Overall, with few exceptions, all the synthetic flavonoids (SFs) exhibited moderate free radical scavenging activity as compared to the standard drug. The test samples in the study showed dose dependant activity of scavenging activity. In nitric oxide radial scavenging activity, test flavonoids VMF 45 and VMF 46 exhibited significant scavenging activity at 50- 100µg/ml concentrations. The SFs VMF 43 and VMF 46 showed a good scavenging activity for hydroxyl, nitric oxide radicals and compounds VMF41, and VMF 43 showed significant scavenging activity at 50 µg/ml to 100µg/ml concentrations for superoxide radicals. However all the SFs at 10µg/ml concentration showed the low or poor radical scavenging activity. Conclusion: It is clear that these synthetic flavonoids (SFs) can be considered as potential antioxidant agents, however needs to be further tested at in vivo experiment to consider them as a lead antioxidant drug candidates.

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Introduction: In recent times, most of the currently available antimicrobial agents have developed resistance. Extensive pharmacological activities including bactericidal and bacteriostatic nature of flavonoids, made them as priority agents in this aspect of research study. Synthetic flavonoids such as hydroxy thiophen derivatives were considered to evaluate for antimicrobial activity in this study.   Objective: The present study involves the analysis for antimicrobial activity of thiophen substituted synthetic flavonoids. Methods: Claisen-Schmidt method of condensation fallowed by oxidative cyclization reactions from substituted hydroxyacetophenone with aromatic aldehydes were used to synthesize the various analogues of flavonoid compounds. Then these compounds after their FTIR, 1H NMR, MS spectral characterization and elemental analysis, were screened for in vitro antibacterial and antifungal activity by using disc diffusion method followed by determining their respective zone of inhibitions. Results: All the synthesized test flavonoid compounds exhibited the good antibacterial and antifungal  spectrum activity over B. subtilis, S. aureus, E. coli and P. aeurugenosa bacteria and Candida albicans and Aspergillus niger fungal microbes. However compounds such as F1, F2 and F4 showed moderately significant antibacterial activity against P. aerugenosa organism than the other test compounds and the same F1 and F2 test compounds exhibited significant antifungal activity at100µg concentration. Conclusion:  The present study demonstrated that the novel thiophen substituted flavonoids (F1, F2, F3 and F4 ) found to have promising antimicrobial and antifungal activity which needs to be confirmed by in vivo studies.

Introduction and Aim: Currently research is focussed on the use of antioxidants in preventing oxidative stress induced diseases. Flavonoids present in plant sources gaining more therapeutic importance due to their antioxidant property, but their solubility and some pharmacokinetic concern, diverted   the current research study towards the synthesis of these flavonoids for their therapeutic potential.  The study was aimed to synthesize and characterize the 2-thiophen flavonoid analogue for free radical scavenging antioxidant activity.   Materials and Methods: The test synthetic compound PNF(3-hydroxy-2-(thiophen-2-yl)-4H-chromen-4-one) a thiophen substituted flavonoid was synthesized from condensation fallowed cyclization reaction in laboratory and DPPH, superoxide, nitric oxide, and hydroxyl radical  scavenging  activity was determined through established in vitro methods.   Results: It suggests that the test flavonoid (PNF) possesses the potent free radical scavenging on DPPH, superoxide, nitric oxide, and hydroxyl radicals with IC50 values of 6.89±25?g/ml,4.04?g/ml, 2.44?g/ml and 2.96?g/ml respectively. The radical scavenging potential of test PNF synthetic compound at different concentrations(10?g-150?g) was compared with that of standard antioxidants such as BHA , ascorbic acid used in the study.   Conclusion: Results from this study indicates that the novel flavonoid PNF exhibited the considerable dose dependant invitro antioxidant activity. These possible activities could be useful to consider the novel synthetic thiophen derived flavonoid as therapeutic antioxidant agent.