Sengul Alpay Karaoglu

Synthesis of some new 1,2,4-triazoles, their Mannich and Schiff bases and evaluation of their antimicrobial activities

4-Phenyl-5-pyridin-4-yl-4H-1,2,4-triazole-3-thiol (3) was obtained in basic media via the formation of 2-isonicotinoyl-N-phenylhydrazinecarbothioamide (2), and converted to some alkylated derivatives (4a,b) and Mannich base derivatives (5a-c). 2-[(4-Phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-yl)thio]acetohydrazide (7) that was obtained by using compound 3 as precursor in two steps was converted to thiosemicarbazide derivative (8), Schiff base derivatives (9) and 5-{[(4-phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-yl)thio]methyl}-1,3,4-oxadiazole-2-thiol (10). Moreover, 5-{[(4-phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-yl)thio]methyl}-3-{[(2-morpholin-4-ylethyl)amino]methyl}-1,3,4-oxadiazole-2(3H)-thione (11) was synthesized via reaction of compound 10 with 2-(4-morpholino)ethylamine. The treatment of compound 8 with NaOH gave 4-(4-methylphenyl)-5-{[(4-phenyl-5-pyridine-4-yl-4H-1,2,4-triazol-3-yl)thio]methyl}-4H-1,2,4-triazole-3-thiol (12), while the acidic treatment of compound 8 afforded 5-{[(4-phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-yl)thio]methyl}-2(4-methylphenyl)-amino-1,3,4-thiadiazole (14). N-Methyl derivative of compound 14 and a Mannich base derivative of compound 12 were synthesized from the reactions of these precursors with methyl iodide and methyl piperazine, respectively. All newly synthesized compounds were screened for their antimicrobial activities. The antimicrobial activity study revealed that all the compounds screened showed good or moderate activity except compounds 3, 5c, 7, 9c, 9e, 9g, 9h, 11, and 13.

Synthesis of some new 1,3,4-thiadiazol-2-ylmethyl-1,2,4-triazole derivatives and investigation of their antimicrobial activities

4-Amino-2-[(5-arylamino-4,5-dihydro-1,3,4-thiadiazol-2-yl)methyl]-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-ones (3a-c) were obtained in acidic media via the formation of 2-[(4-amino-3-aryl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)acetyl]-N-arylhydrazinecarbothioamides (2a-c), and then, compound 3b was converted to methylated derivative, 4. The basic treatment of carbothioamide derivatives, 2a-c, afforded 4-amino-2-[(4-aryl-5-sulphanyl-4H-1,2,4-triazol-3-yl)methyl]-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-ones (5a-c). The alkylation reactions of compounds 4H-1,2,4-triazol-3-ylmethyl-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one derivatives (5a-c) were performed by using methyl iodide or ethyl bromide in the presence of sodium ethoxide, while the treatment of the same intermediates, 5a-c, with aromatic aldehydes produced 2-{[4-(4-aryl)-5-sulphanyl-4H-1,2,4-triazol-3-yl]methyl}-4-(arylmethylene)amino-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-ones (8a-d). The synthesis of 4-amino-(or arylideneamino)-5-(4-methylphenyl)-2-{[(4-methylpiperazin-1-yl or morpholin-4-ylethyl)methyl]-4-aryl-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl}methyl-2,4-dihydro-3H-1,2,4-triazol-3-ones (7a, b and 9) was performed by a one pot three-component Mannich reaction involving the corresponding compounds, 4-(substituted)amino-4H-1,2,4-triazol-3-ylmethyl-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one derivatives 5a, b and 8a, methylpiperazine or 2-(4-morpholino)ethylamine and formaldehyde. The newly synthesized compounds were well characterized by elemental analyses, IR, (1)H NMR, (13)C NMR and mass spectral studies. They were also screened for their microbial activities. The antimicrobial activity study revealed that some of which 2a, c, 3c, 5a-c, 8a-d showed good activity against a variety of microorganisms.

Cyclization of some carbothioamide derivatives containing antipyrine and triazole moieties and investigation of their antimicrobial activities

Acetohydrazide derivative containing both antipyrine and triazole nuclei (5) was obtained starting from ethyl hydrazinecarboxylate derivative (2) and 4-aminoantipyrine (1) by three steps. The treatment of compound 5 with CS(2) afforded the conversion of hydrazide function into 5-mercapto-1,3,4-oxadiazole ring leading to the formation of 7. Then, 7 gave the product containing triazolotriazine moiety (9) by the reaction with hydrazine hydrate. The synthesis of the compounds incorporating the 1,3,4-thiadiazole (10a-c), 1,2,4-triazole (11a-c) or 1,3-thiazole (12, 13) nucleus as third heterocycle was performed by the acidic or basic treatment of compounds 6a-c which were obtained from the reaction of 5 with several isothiocyanates, or by the condensation of 6a with two different phenacyl bromides, respectively. The antimicrobial activity study revealed that all the compounds showed good activities except 3-5.

A comparative study of the antihyaluronidase, antiurease, antioxidant, antimicrobial and physicochemical properties of different unifloral degrees of chestnut (Castanea sativa Mill.) honeys

Abstract This study was planned to investigate some physicochemical and anti-inflammatory, antioxidant, antimicrobial properties of three different degrees of unifloral characters of chestnut honeys. Antihyaluronidase, antiurease and antimicrobial activities were evaluated as anti-inflammatory characteristics. Total phenolic contents, flavonoids, tannins, phenolic profiles, ferric-reducing antioxidant power (FRAP), scavenging activities of 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals were evaluated as antioxidant properties. Color, optical rotation, conductivity, moisture, pH and ash content were evaluated as physicochemical parameters, and some sugars content, prolin, diastase, HMF and minerals (Na, K, Ca, P, Fe, Cu and Zn) were evaluated as chemical and biochemical parameters. All studied physicochemical and biological active properties were changed in line with the unifloral character of the chestnut honeys. A higher unifloral character was found associated with greater apitherapeutic capacity of the honey, as well as biological active compounds.

Synthesis and biological activity studies of new hybrid molecules containing tryptamine moiety

The synthesis of N′-(4-substitutedphenylsulfonyl)-2-{4-[2-(1H-indol-yl)ethyl]-3-(4-chlorobenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl}acetohydrazides (3a–c), 2-{4-[2-(1H-indol-3-yl)ethyl]-3-(4-chlorobenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl}-N′-aryl methylidene acetohydrazides (4a–f) and 4-[2-(1H-indol-3-yl)ethyl]-5-(4-substitutedbenzyl)-2-[(5-sulfanyl-1,3,4-oxadiazol-2-yl)methyl]-2,4-dihydro-3H-1,2,4-triazol-3-ones (5a, b) was performed starting from the corresponding acid hydrazides (2a, b) which was reported earlier. The treatment of 1,3,4-oxadiazole derivatives (5a, b) with hydrazine hydrate produced 4-amino-5-sulfanyl-4H-1,2,4-triazol-3-yl derivatives (6a, b). Then, compound 6b was converted to the corresponding Schiff base (7) by the treatment with anisaldehyde. The synthesis of 5-(4-chlorobenzyl)-4-[2-(1H-indol-3-yl)ethyl]-2-[(4-benzyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl]-2,4-dihydro-3H-1,2,4-triazol-3-one (8) and 5-(4-methylbenzyl)-4-[2-(1H-indol-3-yl)ethyl]-2-[(4-benzyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl]-2,4-dihydro-3H-1,2,4-triazol-3-one (10) was carried out by the reaction of acid hydrazides (2a, b) with aryl iso(thio)cyanates either via the formation of the intermediates (9a, b) (for 10) or direct cyclization (for 8). 1,3-Oxa(thia)zol-2(3H)-ylidene]acetohydrazide derivatives (11a, b) were obtained by the reaction of 9a, b with 4-chlorophenacyl bromide. All newly synthesized compounds were screened for their antimicrobial activities and some of which was found to be active against the test microorganisms.

Synthesis and antimicrobial activity of new piperazine-based heterocyclic compounds

Abstract The hydrazide 5, that was obtained from 1-(4-fluorophenyl)piperazine (1), was converted to the corresponding carbothioamides 6a–c by the reaction with alkyl(aryl) isothiocyanates. The synthesis of conazole analogs 10a–f was performed via the intermediary of triazoles 7a–c. The condensation of triazoles 7a–c with several heterocyclic amines in the presence of formaldehyde afforded the corresponding N-aminoalkylated triazoles 11–14. The effect of different catalysts and solvents on conventional and microwave (MW)-prompted reactions was examined. The synthesized compounds were screened for their antimicrobial activities.

Effect of propolis in gastric disorders: inhibition studies on the growth of Helicobacter pylori and production of its urease

Abstract There is considerable interest in alternative approaches to inhibit Helicobacter pylori (H. pylori) and thus treat many stomach diseases. Propolis is a pharmaceutical mixture containing many natural bioactive substances. The aim of this study was to use propolis samples to treat H. pylori. The anti-H. pylori and anti-urease activities of 15 different ethanolic propolis extracts (EPEs) were tested. The total phenolic contents and total flavonoid contents of the EPE were also measured. The agar-well diffusion assay was carried out on H. pylori strain J99 and the inhibition zones were measured and compared with standards. All propolis extracts showed high inhibition of H. pylori J99, with inhibition diameters ranging from 31.0 to 47.0 mm. Helicobacter pylori urease inhibitory activity was measured using the phenol-hypochlorite assay; all EPEs showed significant inhibition against the enzyme, with inhibition concentrations (IC50; mg/mL) ranging from 0.260 to 1.525 mg/mL. The degree of inhibition was related to the phenolic content of the EPE. In conclusion, propolis extract was found to be a good inhibitor that can be used in H. pylori treatment to improve human health.

Evaluation of Anti-Helicobacter Pylori Activity and Urease Inhibition by Some Turkish Authentic Honeys

Infection with Helicobacter pylori (H. pylori) is an important known risk factor for gastric disease. At least half the world’s population is under the influence of this bacterium type. So many therapeutic studies focus on treat gastric disease. But these treatments could be interrupted due to metabolic toxic and show the drug resistance. The objective of this study was to investigate the effecting degree of H. pylori with different type of honey samples from Turkey. The study was supported by bioactivity results of total phenolic (TPC) and flavonoid content (TFC). The agar-well diffusion assay was carried out on H. pylori strain J99 and the inhibition zones were measured and compared with standards. Inhibition of H. pylori urease as IC50 ranged from 2.67-18.12 mg/mL. These results were supported by TPC and TFC had range from 22.10-79.00 mg Gallic Acid Equivalent (GAE)/100 honey and 0.88-7.08 mg Quercetin Equivalent (QE)/100 g honey, respectively. These results indicate that honey extracts may be appropriate agents to treat H. pylori by inhibition effect.

Salt stress resilience potential of a fungal inoculant isolated from tea cultivation area in maize

Abstract Agriculture needs to be sustained by organic processes in current era as population explosion energy and the number of individuals undernourished are raising public concerns. Global warming poses additional threat by lifting the damage of salt stress especially in agro-economically vital crops like maize whose cultivation dates back to Mayans. To that end, cost-effective and organic fungal agents may be great candidates in stress resilience. We isolated the fungal strain from the soil of tea plants and characterized that via 5.8 S rDNA gene with internal transcribed spacer ITS-1 and ITS-2 regions, then named the target strain as TA. Reduced maximum quantum efficiency of PS II (Fv/Fm), the effective quantum yield of PS2 (ΦPS2), electron transport rate (ETR), photochemical quenching (qP) and increased non-photochemical quenching (NPQ) were detected in maize plants stressed with dose dependent salt. Enhanced Fv/Fm, ΦPS2, ETR, qP and decreased NPQ was observed in TA primed plus NaCl treated plants. TA biopriming significantly increased the lengths, fresh and dry weights of root/shoots and decreased the lipid peroxidation. Maize seedlings bioprimed with TA had less MDA and higher soluble protein, proline, total chlorophyll, carotenoid and RWC under NaCl. Furthermore, SOD, GPX and GR activities were much more increased in root and leaves of TA primed seedlings, however CAT activity did not significantly change. This is the first report to our knowledge that TA reverses the damage of NaCl stress on maize growth through improving water status, antioxidant machinery and especially photosynthetic capacity.

Antimicrobial Activity and Analyses of Six Geranium L. Species with Headspace SPME and Hydrodistillation

Abstract A solid phase microextraction (SPME) method with gas chromatography-mass spectrometry (GC-MS) was used for analyses of the volatile compounds of six Geranium species; G. asphodeloides, G. psilostemon, G. purpureum, G. pyrenaicum, G. robertianum and G. sanguineum. The results were compared with those obtained by hydrodistillation. According to the results of the study, the major compounds identified in the SPME extracts were sabinen (33.5%) (G. asphodeloides), caryophyllene (34.1%, 21.7%, 11.2%) (G. psilostemon, G. purpureum and G. robertianum), germacrene D (25.2%) (G. pyrenaicum), and alloaromadendrene (19.8%) (G. sanguineum) whereas hydrodistillation (HD) essential oils were rich in benzene acetaldehyde (30%, 25.7%) (G. asphodeloides, G. sanguineum), caryophyllene (34.3%, 11.3%) (G. psilostemon and G. robertianum), hexadecanoic acid (36.2%, 15.1%) (G. purpureum and G. pyrenaicum). The oils were screened for antimicrobial activity against 10 microorganisms and showed antibacterial and antifungal activities against Staphylococcus aureus, Bacillus cereus, Mycobacterium smegmatis, Candida albicans and Saccharomyces cerevisiae.