1,721,005 research outputs found
Synthesis and biological evaluation of new Mannich and Schiff bases containing 1,2,4-triazole and 1,3,4-oxadiazole nucleus
Full text link5-(Pyridine-3-yl)-1, 3, 4-oxadiazole-2-thiole 2,
obtaining starting from nicotinic acid hydrazide were converted to the corresponding Mannich bases (3a–c) by the
reaction with several heterocyclic amines in the presence of
formaldehyde. 1,2,4-Triazole-3-thiole, (4) prepared from
1,3,4-oxadiazole-2-thiole (2) was converted to the corresponding Mannich bases (5a–e) by several steps. The
synthesis of Schiff bases (6a–d) was performed from the
reaction of the corresponding triazol-3-thioles with various
aromatic aldehydes. The treatment of Schiff bases containing 1,2,4-triazoles 6c and 6d with morpholine or thiomorpholine generated the corresponding Mannich bases 7a,
b and 8a, b. The synthesized compounds were screened for
their antimicrobial, antilipase, and antiurease activities.
Some of them were found to possess good-moderate antimicrobial, antiurease, and/or antilipase activity
A strategy based on the dispersive liquid-liquid microextraction of cadmium in environmental samples prior to ıts determination by flame atomic absorption spectrometry
Full text linkThis work has been supported by the Scientific Research Projects of Karadeniz Technical University (Project no: 1223), Turkey.A simple method was developed by combining dispersive liquid-liquid microexraction (DLLME) and flame atomic absorption spectrometry (FAAS). For the pre-concentration of trace amounts of cadmium, a new complexation chelate of 2-[(4-phenylpiperazine-5-Thioxo- 4,5-dihydro-1 ,3,4-oxadiazole-2- yl)methyl]-5-methyl-4-[2-(1H-indol e-3-yl)ethyl]-2,4-dihydro-3H-1, 2,4-Triazole-3-one (PPTOMDT) was used and mixed with the solvents of chloroform and methanol. The mixture of the extraction solutions was then directly injected into an aqueous solution containing Cd2+ ions. After centrifugation, the settled phase was diluted with 500 mu L of ethanol/nitric acid and aspirated into the FAAS. The limit of detection (LOD) was found at 0.69 mu g L-1 under optimum conditions. The relative standard deviation (RSD) for 15 replicates at a 3.75 mu g L-1 Cd2+ concentration level was 3.21%. The calibration plot was linear within the range of 2.5-15 mu g L-1 of Cd2+. After the analytical characteristics were determined, the CRM-TMDW-500 Drinking Water and CRM-SA-C Sandy Soil C, both certified reference materials, were analyzed in order to validate the method. The application of the DLLME method has been successfully tested for the determination of cadmium in solid and liquid samples. The recoveries of the spiked sample ranged between 92-96%
Conventional and microwave-assisted synthesis of novel 1,2,4-triazole derivatives containing tryptamine skeleton and evaluation of antimi-crobial activity
No full text1,2,4-Triazole-3-one (3) obtained from tryptamine was transformed to the corresponding car-box(thio)amides via several steps (6a-d). Their reaction with sodium hydroxide performed the 1,2,4-triazole derivatives (7a-d). Compounds 7a-d treatment by 2-bromo-1-(4-chlorophenyl)ethanoneain an ambiance with sodium ethoxide afforded the compounds (8a-d). The reduction reaction of 8a-d afforded 1,2,4-triazoles (9a-d). The synthesis of (10a-d), (11a-d) and (12a-d) was afforded treatment of products 9a-d with 4-chlorobenzyl chloride (for 10a-d) or 2,6-dichlorobenzyl chloride (for 11a-d) or 2,4-dichlorobenzyl chloride (for 12a-d). Besides the improved of entirely novel agents having various chemical features than those of the existing ones, another aim is to combined two or more groups into a single hybrid compound. For this reason, a single compound containing more than one group, each with various modes of effect, could be helpful for the cure of bacterial infections. Microwave-assisted and conventional techniques were utilized for the syntheses. The structures of recently obtained molecules were elucidated on the foundation of1H NMR,13C NMR, FT IR, EI MS methods and elemental analysis. All novel synthesized molecules were investigated for their antimicrobial activity using MIC (minimum inhibitory concentration) method. The aminoalkylation of triazoles (7a-d) formed products 8a-d which have excellent activity against testing bacteria with values between 0.24 and 125 µg/mL. Especially compounds 8a and 8d exhibited much better activity against E. coli than ampicillin used as standard drug. The microwave process ensured a more efficient road to the creation of desired mole-cules. The antibacterial examination demonstrated that after the carbonyl group is increased the anti-bacterial activity of the compounds is greatly increased. That's why molecules formed as a result of the alkylation reactions of triazoles has high activity
An efficient microwave-assisted synthesis of novel quinolone-triazole and conazole-triazole hybrid derivatives as antimicrobial and anticancer agents
No full text1,2,4-Triazole-fluoroquinolone and 1,2,4-triazole–conazole hybrids aredesigned, synthesized, and investigated in vitro against a variety of commondiseases. The structure of the newly synthesized compounds are characterizedfrom spectral data (IR,1H NMR,13C NMR, and LC–MS). The antibacterialactivity against both Gram-positive and Gram-negative bacteria is shown to beenhanced by many of the produced compounds. Also, some of the productsare found to have strong antiproliferative effects aganist HeLa cervical cancercells, whilst demonstrating cytotoxic effects toward normal cell
Synthesis of some new hybride molecules containing several azole moieties and investigation of their biological activities
No full textAlpay Karaoglu, Sengul/0000-0003-1047-83501,2,4-Triazole-3-one prepared from tryptamine was converted to the corresponding carbothioamides by several steps. Their treatment with ethyl bromoacetate or 4-chlorophenacyl bromide produced the corresponding 5-oxo-1,3-thiazolidine or 3-(4-chlorophenyl)-1,3-thiazole derivatives. Acetohydrazide derivative that was obtained starting from tryptamine, was converted to the corresponding Schiff basis and sulfonamide by the treatment with suitable aldehydes and benzensulphonyl chloride, respectively. 2-[(4-Amino-5-thioxo-4,5-dihydro-1H-1,2,4-triazole-3-yl)methyl]-4-[2-(1H-indole-3-yl)ethyl]-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-one was synthesized starting from hydrazide via the formation of the corresponding 1,3,4-oxadiazole compound, while the other bitriazole compounds were obtained by intramolecular cyclisation of carbothioamides in basic media. the treatment of 1,2,4-triazole or 1,3,4-oxadiazole compound with several amines generated the corresponding Mannich bases. Ethyl (2-amino-1,3-thiazole-4-yl)acetate was converted to the corresponding 1,3,4-oxadiazole derivative, arylidenehydrazides, 1,2,4-triazole-3-one and 5-oxo-1,3-oxazolidine derivatives by several steps. the structural assignments of new compounds were based on their elemental analysis and spectral (FT IR, H-1 NMR, C-13 NMR and LC-MS) data. the antimicrobial, antilipase and antiurease activity studies revealed that some of the synthesized compounds showed antimicrobial, antilipase and/or antiurease activity.Karadeniz Technical University, BAP, TurkeyKaradeniz Technical University [8623, 8663, 10641]This work was supported by Karadeniz Technical University, BAP, Turkey (Ref. nos. 8623, 8663 and 10641)
Microwave-assisted synthesis of novel mannich base and conazole derivatives containing biologically active pharmacological groups
No full textBackground: The aim of this study was to synthesize new Mannich bases and conazol derivatives with biological activity by the microwave-assisted method. Introduction: 1,2,4-Triazole-3-one (3) acquired from tryptamine was transformed to the corresponding carbox(thio)amides (6a-c) via several steps. Compounds 6a-c were refluxed with sodium hydroxide to yield 1,2,4-triazole derivatives (7a-c). Compounds 3 and 7a-c on treatment with different heterocyclic secondary amines in an ambiance with formaldehyde afforded the Mannich bases 8-15 having diverse pharmacophore units with biologically active sites. The reaction of compound 3 and 2-bromo-1-(4-chlorophenyl) ethanone in the presence of sodium ethoxide gave the corresponding product 2-substituted-1,2,4-triazole-3-one, 16, which was reduced to 1,2,4-triazoles (17). Synthesis of compounds 18, 19, and 20 was carried out starting from compounds 17 with 4-chlorobenzyl chloride (for 18), 2,4-dichlorobenzyl chloride (for 19), and 2,6-dichlorobenzyl chloride (for 20). Methods: The conventional technique was utilized for the synthesis of compounds, 3-7, and microwave-assisted technique for the compounds, 8-20. That is, green chemistry techniques were applied during these reactions. The structures of molecules were elucidated on the foundation of 1H NMR, 13C NMR, FT-IR, EI-MS methods, and elemental analysis. Novel synthesized molecules were investigated for their antimicrobial activity using MIC (minimum inhibitory concentration) method. Results: Aminoalkylation of triazole derivatives 3 and 7a-c with fluoroquinolones such as ciprofloxacin and norfloxacin provided an enhancement to the bioactivity of Mannich bases 8-11 against the tested microorganisms. The MIC values ranged between <0.24 and 3.9 μg/mL. Moreover, molecules 10 and 11 exhibited more effects on M. smegmatis than the other compounds by the MIC values of <1 μg/mL. They have shown very good antituberculosis activity. Conclusion: Most of the synthesized structures were observed to have excellent antimicrobial activity against most microorganisms taken into account. These molecules have better activity than the standard drug ampicillin and streptomycin
Antibacterial and antioxidant activities of traditional medicinal plants from the Erzurum region of Turkey
Full text linkBackground In this study, 13 different extracts were investigated which are grown in the region of Erzurum. Objective The aim of this study was to screen various plant extracts that are known and used for medicinal purposes such as Ferula communis L., Rumex patientia L., Gundelia tournefortii L., Rheum ribes L., Asphodeline taurica, Polygonum arenastrum, Allium schoenoprasum L., and Ferula orientalis L. Materials and methods Medicinal parts of plants such as leaves, flowers, and stems were investigated by 2,2-diphenyl-1-picrylhydrazyl, ferric reducing antioxidant power, and cupric reducing antioxidant capacity assays: Centaury and Blackthorn. Total phenolic content, total flavonoid content, and antimicrobial properties were also determined. Antibacterial and antifungal activities were investigated by the microdilution method and the agar diffusion method respectively. Results Accordingly, the results of the Rheum ribes L. plant have the highest antioxidant activity among all analyses made. But in almost all antioxidant analysis methods, the lowest antioxidant activity was found in Ferula orientalis L. According to the antibacterial analysis applied, it was found that the plant extracts were generally more effective on yeast strains than the test bacteria used; that is, most of the plants have antifungal effect. Conclusions Due to their antimicrobial, antifungal, and antioxidant properties, the extracts of these plants might be used as natural sources in the pharmaceutical and cosmetic industries
Synthesis of novel Schiff bases using green chemistry techniques; antimicrobial, antioxidant, antiurease activity screening and molecular docking studies
No full textSchiff base derivatives were synthesized in this study via conventional, microwave irradiation and ultrasound sonication methods. Optimization conditions were examined for several parameter such as solvent, reaction time and yield. After determining the optimization conditions, the compounds were synthesized by using ultrasound sonication. The structures of the synthesized compounds were examined by spectral data, and the antiurease, antioxidant and antimicrobial activities of the Schiff bases derivatives were investigated due to the imine group (-C=N-) and promising results were obtained. The enzyme inhibitory potentials of these compounds were further validated through molecular docking studies. Also, In Silico ADME prediction studies were calculated for compounds
Chemical composition of essential oil by SPME and evaluation of antimicrobial, antioxidant activities of quercus inectoria GALL
Full text linkQuercus infectoria galls have been utilized to cure widespread illnesses. In line with it, this paper aims to investigate the chemical combination of the volatile oils obtained from galls of Q. infectoria and evaluate their antioxidant and antimicrobial features. The volatiles of Q. infectoria has been isolated by solid-phase microextraction (SPME). The compositions of the volatiles were revealed via gas chromatography coupled with mass spectrometry (GC-MS). Twenty-nine substances have been characterized in the volatile essential oil of Q. infectoria. The major components of the volatile oil were (Z)-Anethol 28.55%, pentadecanolide (26.44%), diethyl phthalate (6.46%), and acetoin (5.66%). Q. infectoria showed good-moderate antimicro-bial (Staphylococcus aureus, Streptomyces griseolus, Pseudomonas citronellosis) and antifungal (Candida glabrata, Candida krusei) activities against to test microorganisms with MIC value 250 μg/mL and 125 μg/mL, respectively. Also, total flavonoid and total polyphenol amounts were found for Q. infectoria, and our to-tal polyphenol result (342.87 mg GAE/g) was found higher than the studies in the literature. At the same time Q. infectoria has been observed to have high antioxidant activity according to DPPH, FRAP, and CUPRAC assays. Especially it exhibited excellent DPPH activity for the IC50 rate of 0.002 μg/mL which is higher than the standard Trolox (IC50 = 0.008 μg/mL). This study is important because it is the first one, which reports the determination of essential oil, total polyphenol, flavonoid contents, antioxidant, and antimicrobial activities all together for Q. infectoria
Chemical composition, antimicrobial, and antioxidant activities of medicinal plants nutsedge and fenugreek
Full text linkPurple nutsedge roots (Cyperus rotundus L.) and fenugreek seeds (Trigonella foenum-graecum L.) have been traditionally used as food and to treat common ailments. After extraction by solid-phase microextraction (SPME), the chemical structure of the revealed volatile fractions was researched with gas chromatography with mass spectrometry (GC-MS). The determined substances of the C. rotundus were pentadecanolide (72.0%), palmitic acid (8.2%), 16-hydroxy-6-hexadecenoic acid omega lactone (4.4%), and (Z)-anethol (3.9%). Most of the identified compounds of the T. foenum-graecum were pentadecanolide (61.3%) and (Z)-anethol (16.5%). The C. rotundus showed good antifungal activity against the yeast strands of Candida albicans and Candida krusei. Minimum inhibitory concentration (MIC) numbers were 250 and 125 µg/mL, respectively. However, the T. foenum-graecum seeds did not show any effect against the test microorganisms. The C. rotundus roots in particular exhibited good 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity with an IC50 number of 0.91 mg/mL
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