Synthesis and Biological Activity of New Schiff Bases of Benzylideneamine Bearing Thiophene, 1,2,4-triazolone, 1,3,4-oxadiazole, Morpholine Moieties

WOS: 000433998700002Background: Schiff bases have a broad spectrum of biological activities including antiviral, antibacterial, antifungal, antimalarial, anti-inflammatory antiproliferative and antipyretic properties. 1,3,4-oxadiazoles have been reported to show spectrum of biological activities including such as antiviral, fungicidal, antineoplastic, antimicrobial anti-HIV, antitubercular, antihypoglycemic, antimalarial, antioxidant, analgesic, anti-inflammatory, anticonvulsant, anticancer and inhibition of tyrosinase, antitumor and antiproliferative. Morpholine is known as a valuable structure for the synthesis of more efficacious antimicrobial agents. Therefore, the study presents the synthesis, antimicrobial and antioxidant evaluation of a series of 1,3,4 substituted oxadiazole derivatives Methods: Synthesis of compounds 2(a-d): 0.01 mol 4-amino-1-((5-mecapto-1,3,4-oxadiazol-2-yl) methyl)-3-(thiophen-2-ylmethyl)-1H-1,2,4-triazol-5(4H)-one (1) and 0.01 mol aromatic aldehydes were heated in oil bath without solvent for 2-3 h at 160-180 0 C. Then on completion of the reaction, followed by TLC examination, allowed to cool to room temperature. The separated solid was filtered and crystallized from a mixture of DMSO and water (1:2). Synthesis of compounds 3(a-d). A mixture of formaldehyde (0.02 mol) and morpholine (0.02 mol) in DMF was added to solution of compound 2 (0.01 mol) in DMF. The resulting mixture was stirred overnight at room temperature. The precipitated solids were filtered, washed with water and recrystallized from DMF/water. Determination of Antioxidant Activity: The FRAP method was used for the determination of total antioxidant capacity, based on the reduction of yellow Fe3+ - TPTZ complex to the blue Fe2+ - TPTZ complex by electron donating substance under acidic condition. Radical scavenging activity of compounds against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical was spectrophometrically at 517 nm. The assay is based on the color change of the DPPH solution from purple to yellow as the radical is deactivated by the antioxidants. Briefly, the stock solutions of each extract were prepared in DMSO and if necessary sequential dilutions were made. Results: All of the compounds synthesized in this study, except 3c, showed antioxidant activity in the free-radical scavenging (DPPH) and ferric reducing (FRAP) tests at different grades (Figs. 1 and 2). The antioxidant activities of the compounds were differentially influenced in the DPPH and FRAP tests from the substituents of Schiff and Mannich bases. It has been determined that the effects of the substituent type of the thiophene ring on the activity were different for Schiff bases (2a-d) and Mannich bases (3a-d). High-to-low activity sequencing was H-CN-NO2-Br (in DPPH assay) and NO2-H-CN-Br (FRAP assay) on schiff bases while Br-H-NO2-CN (in DPPH assay) and H-BrNO2-CN (in FRAP assay) on mannich bases. Similarly, in DPPH and FRAP assay, the Schiff bases (2a-d) were more active when compared with the Mannich bases (3a-d). Conclusion: In the work, new eight Schiff bases bearing thiophene, 1,2,4-triazolone, 1,3,4-oxadiazole, morpholine moieties were synthesized. The new compounds, well characterized by elemental analyses, IR, H-1 NMR and C-13 NMR were tested for their antioxidant and antimicrobial activities. In DPPH and FRAP assay, the compounds 2(a-d) with Schiff base were more active when compared with the compounds 3(a-d) containing Schiff base and morpholine substituent and 2(a-c) had a respectable antioxidant potential. The lowest MIC value, i.e. the highest antimicrobial activity, were observed in compound 2a against Bacillus cereus RSKK 709 with a MIC value of 31.25 mu g/mL.Karadeniz Technical UniversityKaradeniz Teknik University [KTU BAP 5577]This study was supported by grants from Karadeniz Technical University (KTU BAP 5577)

In vitro seed germination, plantlet growth, tuberization, and synthetic seed production of Serapias vomeracea (Burm. f.) Briq.

WOS: 000390711200004Orchids are considered recalcitrant plants in in vitro propagation. Due to the lack of appropriate micropropagation techniques for mass production and damage to their ecological distribution posed by local gatherers, these species are threatened with extinction, including Serapias vomeracea (Burm. f.) Briq. In this research, we put forward a complete micropropagation method covering in vitro micropropagation, synthetic seed formation, germination in soil, and acclimatization to ambient conditions. To the best of our knowledge this is the first report of successful synthetic seed formation and germination of S. vomeracea. Initially, seeds were germinated in different culture media and also media supplemented with different concentrations of plant growth regulators. Effects of plant growth regulators on tuber formation, glucomannan contents, and different growth parameters were evaluated throughout the study. The best germination rate (84.03%) was achieved on Orchimax including activated charcoal medium and supplemented with 2.0 mg/L 6-benzyladenine. The longest shoot elongation amongst plantlets was observed on the same medium supplemented with 0.25 mg/L thidiazuron, whereas 2.0 mg/L indole-3-butyric acid favored leaf formation. Higher indole-3-butyric acid concentrations were found to be more effective in the formation and elongation of roots. Orchimax medium supplemented with zeatin (2.0 mg/L) was superior to the others in terms of tuber formation and glucomannan content therein. Adaptation of seedlings to soil conditions and germination abilities of synthetic seeds were also studied and seedlings were successfully acclimatized and adapted to soil conditions.Ministry of Science, Industry and Technology, Republic of TurkeyMinistry of Science, Industry & Technology - Turkey [00102.TGSD.2009]The authors are grateful to the Ministry of Science, Industry and Technology, Republic of Turkey, for supporting the project (No. 00102.TGSD.2009) under the framework of Techno-Entrepreneurship

Biological Activities of Extracts and Essential Oil of Thymus transcaucasicus Ronniger

WOS: 000373724000021Hexane, chloroform, water extracts and essential oil obtained from flowering aerial parts of Thymus transcaucasicus Ronniger were screened for potential in vitro antioxidant, antimicrobial and antiviral activities. Chemical composition of essential oil was determined by employing GC-MS analysis; thymol being the main component in 55%. The essential oil and extracts were screened for their possible antioxidant activities by two complementary test systems, namely DPPH free radical scavenging and beta-Carotene color bleaching test-a spectrophotometric method. The highest free radical scavenging activity was observed in the essential oil (IC50: 20 mu g/ml) whilst, in beta-Carotene color bleaching test, hexane extract showed superiority, with an inhibition rate at 72.3%. Antibacterial and antifungal activities of the extracts were also evaluated and among which the essential oil exerted better activity against all microorganisms tested except for Pseudomonas aeruginosa. Nevertheless, none was effective against test viruses, namely HSV and Influenza.Karadeniz Technical University (BAP)Karadeniz Teknik University [2007.111.004.4]The authors appreciate for the financial support of Karadeniz Technical University (BAP Project No. 2007.111.004.4)

New bis 1,3,4-oxadiazole derivatives: syntheses, characterizations, computational studies, and antioxidant activities

WOS: 000450109800007In this study, two new bis oxadiazole derivatives (2a and 2b) were synthesized. The new compounds were characterized by elemental analyses, IR, H-1 NMR, C-13 NMR, and mass spectral studies and were tested for their antioxidant activity. According to the results, it was observed that the synthesized compounds (2a and 2b) had a very high activity in both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing ability of plasma (FRAP) tests. The approximate geometries of the compounds 2a and 2b were prepared with GaussView5 visualization program. The optimized molecular geometric parameters. vibrational wavenumbers, UV-vis parameters, and HOMO-LUMO simulations were computed using Gaussian 09W program. The computations were performed at 6-3114-14(d,p) basis set using the B3LYP functional in density functional theory (DFT) method. The harmonic vibrational wavenumbers computed in gas phase were scaled with 0.958 (1700-4000 cm(-1)) and 0.983 (0-1700 cm(-1)) for the B3LYP/6-3114-1-G(d,p) level. To calculated the UV-vis spectroscopic parameters with TD-DFT method, the compounds 2a and 2b were optimized in DMF and DMSO solvents using the integral equation formalism polarizable continuum model (IEFPCM) method at the B3LYP/6-311++G(d,p) level. The HOMO, LUMO, and UV-vis analyses were studied to interpret intramolecular charge transfers

New Chalcone Derivative: Synthesis, Characterization, Computational Studies and Antioxidant Activity

Ozdemir, Namik/0000-0003-3371-9874WOS: 000505999500006A new chalcone derivative, called as 1-(4-(benzylideneamino)phenyl)-3-(furan-2-yl)prop-2-en-1-one (I), was synthezised and characterized by spectral methods (infrared (IR) and proton and carbon-13 nuclear magnetic resonance (H-1- and C-13-NMR) spectroscopy). A computational study was performed by the density functional theory (DFT) method. Spectral data of compound I optimized by using 6-311G(d,p) and 6-311++G(d,p) basis sets were obtained by 6-311++G(d,p) basis set. The E-Z isomerism for newly synthesized chalcone derivative was investigated by considering four isomeric form, E/E, E/Z, Z/E and Z/Z. The results show that, as assumed and thus named, the chalcone DOI: derivative is in the E/E form. In addition, quantum chemical parameters were calculated by using DFT method with 6-311++(d,p) basis set. Antioxidant activity of compound I was determined by the feiric reducing ability of plasma (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay methods. Compound I has low antioxidant activity.Karadeniz Technical UniversityKaradeniz Teknik UniversityThis study was supported by grants from Karadeniz Technical University

In vitro antimicrobial, antioxidant, and antiviral activities of the essential oil and various extracts from Thymus nummularis M. Bieb.

WOS: 000379195200007This study is designed to determine the in vitro antioxidant, antimicrobial and antiviral activities of hexane, chloroform, water extracts and essential oils of Thymus nummularis M. Bieb. Chemical composition of essential oil was determined by employing GC-MS and GC-FID analyses; thymol being the main component in 58 %. The oil and extracts were screened for their possible antioxidant activities by two complementary test systems, namely DPPH free radical scavenging and Carotene color bleaching test a spectrophotometric method. The highest free radical scavenging activity was observed in the essential oil (IC50: 2.3 mu g/ml) whilst, in beta-Carotene color bleaching test, chloroform extract showed superiority, with an inhibition rate at 79.95 %. Antibacterial and antifungal activities of the extracts were also evaluated and among which the essential oil exerted better activity against all microorganisms tested except for Pseudomonas aeruginosa. Nevertheless, none was effective against test viruses, namely HSV and Influenza

Synthesis and characterization of metallophthalocyanine with morpholine containing Schiff base and determination of their antimicrobial and antioxidant activities

aktas, ayse/0000-0002-7347-4018WOS: 000488798700010In this work, novel metallophthalocyanine compounds (M = Zn, Cu, Co) bearing four 2-methoxy-4-{(Z)-[(4-morpholin-4-ylphenyl) imino] methyl} phenol at the peripheral positions were sythesized starting from the new phthalonitrile derivative (2). These new compounds (2-5) have been characterized by a combination of FT-IR, H-1 NMR (for compounds 2 and 3), C-13 NMR (for compound 2), UV-Vis (for compounds 3,4 and 5) and mass spectrophotometry techniques. Antioxidant activities of the metallophthalocyanines were investigated by using DPPH free radical scavenging assay and FRAP (ferric ion reducing antioxidant power) method. The antimicrobial activity of the synthesized metallo phthalocyanine compounds (3-5) were determined against the selected different six standart bacteria isolates by microdilution broth assay with Alamar Blue Dye. Most affected bacteria from the compounds were standard E. coli and S. typhimurium (MIC 625 mu g/ml). Standart Y. enterocolitica and S. aureus have been less affected by the compounds (MIC 10.000 mu g/ml). (C) 2019 Published by Elsevier B.V.Research Fund of Artvin Coruh Universty [P.N: 2018.F91.02.01]; Scientific & Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [118Z578]We are greateful of financal support from the Research Fund of Artvin Coruh Universty (P.N: 2018.F91.02.01) and The Scientific & Technological Research Council of Turkey (TUBITAK, project no: 118Z578]