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We report herein one-pot synthesis and the antibacterial and antitubercular activities of 2,5-disubstituted-1,3,4-oxadiazole compounds obtained by hybridization of a well-known antitubercular agent isoniazid ( INH) with four broad-spectrum antibiotics belonging to fluoroquinolone ( FQ) class. The work is aimed at designing and developing potential antimicrobial agents having synergistic action due to the coupling of INH and FQ through the biologically active 1,3,4-oxadiazole nucleus. The synthesized compounds are expected to have low toxicity as compared to INH due to the absence of free hydrazide group in the chemical structure of the prepared derivatives. The antibacterial activities of the 1,3,4 oxadiazole derivatives were also tested against several Gram-positive and Gram-negative pathogenic bacterial strains. The antitubercular activity was evaluated against M. tuberculosis H37Rv strain, and the results were compared with that of the positive control INH. The title compounds showed excellent antimicrobial and promising antitubercular activity in comparison to the parent fluoroquinolones and INH, respectively. [ABSTRACT FROM AUTHOR]

Olive oil isolated from the fruits of the Olea europaea L. is an important part of Mediterranean diet. It is known for its diverse biological actions. Furthermore, a little amount of fixed oil and other bioactive components can also be extracted from the olive seeds which are considered as byproduct of olive oil extraction. Therefore, this study was designed to analyze the fatty acid composition and to perform in vitro biological studies on fixed oil isolated from olive seeds. The fixed oil was isolated from the olive seeds of Syrian and Greek black olive fruits by using Soxhlet apparatus. The purity was checked by measuring its refractive index. Composition of two isolated oils and a commercially available virgin olive oil was determined by preparing their Methyl esters (FAME) followed by GC-MS analysis. Various in vitro assay methods were used to investigate activities such as antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH), cytotoxic activity by using Brine shrimps lethality bioassay and antimicrobial activity against two bacterial strains; Staphylococcus aureus and Escherichia coli by agar well diffusion method. GC-MS analysis revealed that the two isolated oils differ quantitatively in chemical composition with oleic acid identified as the major chemical constituent (62.6% and 73.56%). Both the fixed seed oils showed a concentration dependent DPPH radical scavenging activity ranging from 8 to 76% inhibition. The oils also exhibited excellent cytotoxic activity but no antimicrobial activity was observed. The chemical composition of the isolated fixed olive seed oil is found to be almost similar to the commercially available fruit olive oil. The fixed oil from the seeds of olive fruits possesses useful biological actions. Further studies are needed to isolate and quantify their bioactive constituents. [ABSTRACT FROM AUTHOR]

Background: The leaves of Sesbania grandiflora have been used in local traditional medicine since ancient times. In the present study we investigated, in vivo and in vitro, the potential health benefits of various fractions of the ethanolic extract of these leaves. Materials and methods: Crude ethanolic extract (CEE) of S. grandiflora leaves was partitioned into ethyl acetate soluble fraction (EASF), petroleum ether soluble fraction (PSF), carbon tetrachloride soluble fraction (CTSF), chloroform soluble fraction (CSF), and water soluble fraction (WSF). The extracts were evaluated for their thrombolytic, membrane stabilizing (anti-inflammatory), antimicrobial, and antidiarrheal activities. The results were compared to the effects of standard drugs: streptokinase for the thrombolytic, acetylsalicylic acid (ASA) for the membrane stabilizing, kanamycin for antimicrobial, and loperamide for the antidiarrheal activities. Results: For thrombolysis, EASF showed the highest % of clot lysis (59.6%) among all fractions, while streptokinase and water resulted in 69.2% and 3.1% clot lysis respectively. With respect to the membrane stabilizing activity, the EASF significantly inhibited the hemolysis of human erythrocytes induced by hypotonic solution (64.3±0.6%) or by heat (57.2±0.7%). The other fractions exhibited no membrane stabilizing effect. By contrast ASA resulted in 73.9±0.3% inhibition of osmotically induced hemolysis and a slightly lower level of inhibition in the case of heat-induced hemolysis (70.1±0.3%). The antidiarrheal activity was evaluated in the mouse model. The unfractionated, CEE reduced the number of defecation episodes by 25.0% at a dose of 200 mg/kg and by 41.1% at dose 400 mg/kg body weight. All extract fractions exhibited significant antibacterial activity, which was higher against Gram negative bacteria than Gram positive bacteria. Since the pharmacological activities of S. grandiflora are due to the presence of bioactive compounds we detected and quantified the presence of significant levels of flavonoid and tannin substances. Conclusion: Leaves of Sesbania grandiflora have the potential to be used as a remedy for thrombosis, diarrhea, and inflammatory diseases and against few important bacterial pathogens. [ABSTRACT FROM AUTHOR]