Some series of arylidene barbiturates and thiobarbiturates were evaluated for their antibacterial, antioxidant, and urease inhibition activities. The arylidene barbiturates and thiobarbiturates were tested for antimicrobial activity using the agar well diffusion technique against 13 bacteria. The synthesized compounds (1a–g) were screened for antiurease and antioxidant activities. The results showed that the synthesized compounds (1a–g) had effective antiurease, antioxidant, and antibacterial activities.

A novel bioactive molecule produced by Bacillus thuringiensis subsp. kurstaki Bn1 (Bt-Bn1), isolated from a common pest of hazelnut, Balaninus nucum L. (Coleoptera: Curculionidae), was determined, purified, and characterized in this study. The Bt-Bn1 strain was investigated for antibacterial activity with an agar spot assay and well diffusion assay against B. cereus, B. weinhenstephenensis, L. monocytogenes, P. savastanoi, P. syringae, P. lemoignei, and many other B. thuringiensis strains. The production of bioactive molecule was determined at the early logarithmic phase in the growth cycle of strain Bt-Bn1 and its production continued until the beginning of the stationary phase. The mode of action of this molecule displayed bacteriocidal or bacteriolytic effect depending on the concentration. The bioactive molecule was purified 78-fold from the bacteria supernatant with ammonium sulfate precipitation, dialysis, ultrafiltration, gel filtration chromatography, and HPLC, respectively. The molecular mass of this molecule was estimated via SDS-PAGE and confirmed by the ESI-TOFMS as 3,139 Da. The bioactive molecule was also determined to be a heat-stable, pH-stable (range 6-8), and proteinase K sensitive antibacterial peptide, similar to bacteriocins. Based on all characteristics determined in this study, the purified bacteriocin was named as thuricin Bn1 because of the similarities to the previously identified thuricin-like bacteriocin produced by the various B. thuringiensis strains. Plasmid elution studies showed that gene responsible for the production of thuricin Bn1 is located on the chromosome of Bt-Bn1. Therefore, it is a novel bacteriocin and the first recorded one produced by an insect originated bacterium. It has potential usage for the control of many different pathogenic and spoilage bacteria in the food industry, agriculture, and various other areas.

Thirty-seven entomopathogenic bacteria isolated from six common pests of hazelnut in the Black Sea Region of Turkey have been screened for their potential of antibacterial substance production against indicator bacteria by the agar spot assay and well diffusion assay. Results indicated that 13.5% of entomopathogenic bacteria, Pseudomonas fluorescens (Pf-Xd1), Bacillus polymyxa (Bp-Ar2), Bacillus thuringiensis (Bt-Bn1), Serratia marcescens (Sm-Mm3) and Pseudomonas flourescens (Pf-Aa4) isolated from pests of Xyleborus dispar, Anoplus roboris, Balaninus nucum, Melolontha melolontha and Agelastica alni, respectively, showed significant levels of inhibitor activities against indicator bacteria. Well diffusion assay showed that supernatants of Bp-Ar2, Bt-Bn1 and Sm-Mm3 have antibacterial activity, whereas Pf-Xd1 and Pf-Aa4 did not show any activity. Furthermore, the antibacterial activity of the substance produced by the Bp-Ar2 has a narrow spectrum, whereas those of Bt-Bn1 and Sm-Mm3 exhibit broad spectrum. The production of these antibacterial substances were similarly determined at early logarithmic phase in the growth cycle of three bacteria and continued until the beginning of the stationary phase as primer metabolite. In addition, optimal pH (at 7-9 forBt-Bn1 and 5-9 forSm-Mm3), medium (Muller Hinton broth forBt-Bn1 and Luria Bertani broth forSm-Mm3), temperature (25 • C forBt-Bn1 and Sm-Mm3) and production time (24h forBt-Bn1 and 72h forSm-Mm3) of these substances were determined. Our results demonstrate that entomopathogenic bacteria are a potential source of antibacterial substances.

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A series of new bis triazole Schiff base derivatives (4) were prepared in good yields by treatment of 4-amino-3,5-diphenyl-4H-1,2,4-triazole (3) with bisaldehydes (1). Schiff bases (4) were reduced with NaBH 4 to afford the corresponding bisaminotriazoles (5). All the new compounds were characterized by IR, 1 H NMR and 13 C NMR spectral data. Their overall extraction (log K ex ) constants for 1 : 1 (M : L) complexes and CHCl 3 /H 2 O systems were determined at 25 6 0.1 C to investigate the relationship between structure and selectivity toward various metal cations. The extraction equilibrium constants were estimated using CHCl 3 /H 2 O membrane transfer with inductively coupled plasma-atomic emission spectroscopy spectroscopy. The stability sequence of the triazole derivatives in CHCl 3 for the metal cations was exhibited a characteristic preference order of extractabil-]. The compounds were tested for anti-microbial activity applying agar diffusion technique for 11 bacteria.

The acylhydrazone compound named ethyl N'-furan-2-carbonylbenzohydrazonate was synthesized by the condensation of ethyl benzimidate hydrochloride with furan-2-carbohydrazide. The treatment of the acylhydrazone with hydrazine hydrate afforded 4-amino-3-furan-2-yl-5-phenyl-1,2,4-triazole. The usage of this compound with various aromatic aldehydes resulted in the formation of 4-arylidenamino-3-furan-2-yl-5-phenyl-1,2,4-triazoles. Sodium borohydride reduction of 4-arylidenamino derivatives afforded 4-alkylamino-3-furan-2-yl-5-phenyl-1,2,4-triazoles. The obtained products were identified by FT-IR, (1)H-NMR, (13)C-NMR. A series of compounds were evaluated for their antibacterial, antiurease, and antioxidant activities. The results showed that the synthesized new compounds had effective antiurease and antioxidant activities.

A new bis schiffbases, 3 a-b were synthesized compound 2 with various bis aldehydes. Compounds 3 a-b have been reduced with NaBH(4) to afford the corresponding bis amino triazole compounds 4 a-b. The obtained products 3 a-b and 4 a-b were identified by FTIR, (1)H-NMR, (13)C-NMR. A series of triazol derivatives were evaluated for their antibacterial, antioxidant, antiurease and antielastase activities. The results showed that the synthesized new bis-1,2,4-triazole derivatives had effective antioxidant, antiurease and antielastase activities.

In a modern context, at least 25% of the active ingredients of pharmacologically produced medicines are derived from plants. In addition, the active ingredients of many synthetically produced medicines are similar to chemicals that were first isolated from medicinal plants (Berber et al. 2013). The active ingredients in medicinal plants have been shown to exhibit high biological capability (Bhouri et al. 2010; Kilani-Jaziri et al. 2011) and these plants seem to be the best resources for the discovery of novel bioactive chemicals in the design of new drugs. Recently, there has been considerable interest in the antimicrobial (Rates 2001), antioxidative (Kilani-Jaziri et al. 2011) and antigenotoxic activities (Amkiss et al. 2013) of medicinal plants. At present, alternative antimicrobial medicines are needed, in particular, for the treatment of infectious diseases. Mounting resistance of microorganisms to many antibiotics has led to increasing difficulties in the treatment of infectious diseases. In this context, local medicinal plants are known to be rich in antimicrobial properties and thus, a source of novel antimicrobials (Rates 2001; Kilani-Jaziri et al. 2011). Furthermore, some medicinal plants are reported to exhibit high antioxidant activity (Kilani-Jaziri et al. 2011), and plant phenolics are generally the source of these natural antioxidant properties (Atoui et al. 2005; Cavlak and Yagmur 2016). Antioxidants prevent the formation of free radicals produced routinely in all cells as part of their normal function; however, free radical accumulation in cells may play a role in many diseases (Young and Woodside 2001). Recently, there has been a growing interest in natural antioxidants of plant origin. Natural antioxidants obtained from medicinal plants can prevent the formation of free radicals, thus indicating their potential as novel therapeutic agents (Nogochi and Nikki 2000; Chaabane et al. 2012). Of late, considerable research has been focused on the antigenotoxic activity of medicinal