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

BACKGROUND: A new series of 13 piperazinyl flavone derivatives has been synthesized and examined for their in vitro antiradical and antioxidant activities in response to the pharmacy industry's increasing demand for new non-toxic anti-inflammatory and anticancer drugs. METHOD: Their antioxidant activity was evaluated by the reactive oxygen species (ROS) scavenging assays, 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 ferric reducing antioxidant potency (TAC) method, and was compared to known positive controls, herbal infusions, 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, in some 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 several synthesized compounds, they were higher than chamomille infusion and penicillins. Ferric reducing antioxidant powers (TAC) for the piperazinyl flavone derivatives were in the range 7 ± 0.5 to 104 ± 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 active as antioxidants, thus may be suggested as pharmacologically interesting ones.

[Comparison of minimum inhibitory concentrations of group M penicillins against Staphylococcus aureus. Practical impact on diagnosis and treatment]. / Comparaison des concentrations minimales inhibitrices des pénicillines du groupe M vis-à-vis des Staphylococcus aureus. Incidences pratiques sur le diagnostic et la thérapeutique.

The MICs were determined in usual conditions and in special conditions for the detection of heterogeneous methicillin resistance. The study involved 40 strains of Staphylococcus aureus of the 3 categories of homogeneous resistant, heterogeneous resistant and sensitive strains. The MICs of the 4 main compounds of the group M penicillins, methicillin, oxacillin, cloxacillin and dicloxacillin, were lower in the presence of a higher number of chlorine atoms on the molecule. The heterogeneous strains were even sensitive to dicloxacillin. The MIC for a notable fraction of resistant strains were lower than the critical value, i.e. these strains entered the category of dicloxacillin sensitive even in reading conditions theoretically leading to the detection of heterogeneous resistance. These in vitro observations are of value in the presence of methicillin sensitive strains, since antibiotics containing one or two chlorine atoms will probably be more therapeutically effective. But the bacteriologist should pay more careful attention to the detection of methicillin resistant and heteroresistant strains, since the resistance in vivo is extended to other penicillinase-resistant penicillins or penicillins M.

Influence on oropharyngeal and nasal carriage of Staphylococcus aureus by dicloxacillin therapy in patients undergoing oral surgery.

71 healthy oral, throat and nasal carriers of Staphylococcus aureus undergoing surgical removal of impacted mandibular third molars were assigned to the following regimens. 40 patients received dicloxacillin 500 mg orally 60 min before the operation and then 500 mg dicloxacillin 3 times daily for 7 days and 31 patients no antibiotic. Oropharyngeal and nasal cultures were obtained from each patient before, during and after the operation. Dicloxacillin reduced the carrier rates significantly. No increase in in vitro antibiotic resistance was observed in the staphylococcal isolates obtained after therapy. Dicloxacillin was well tolerated and toxicity was not encountered in any patient.