124 research outputs found
Synthesis of eperezolid-like molecules and evaluation of their antimicrobial activities
No full textAlpay Karaoglu, Sengul/0000-0003-1047-8350WOS: 0003088203000113-Fluoro-4-(4-phenylpiperazin-l-yl)aniline (II) prepared from 3,4-difluoro nitrobenzene was converted to the corresponding Schiff bases (III) and (IV) by treatment with 4-methoxybenzaldehyde and indol-3-carbaldehyde, respectively. Treatment of amine (II) with 4-fluorophenyl isothiocyanate afforded the corresponding thiourea derivative (V). Compound (V) was converted to thiazolidinone and thiazoline derivatives (VI) and (VII) by cyclocondensation with ethylbromoacetate or 4-chlorophenacylbromide, respectively. The synthesis of carbothioamide derivative (X) was performed starting from compound (II) by three steps. Treatment of compound (X) with sodium hydroxide, sulfuric acid, or chlorophenacyl bromide generated the corresponding 1,2,4-triazole (XI), 1,3,4-thiadiazole (XII), and 1,3-thiazolidinone (XIII) derivatives, respectively. The structural assignments of new compounds were based on their elemental analysis and spectral (IR, H-1-NMR, C-13-NMR, and LC-MS) data. In the antimicrobial activity study all the compounds revealed high anti-Mycobacterium smegmatis activity.Karadeniz Technical University, BAP, TurkeyKaradeniz Teknik University [2007.111.002.6]The work was supported by Karadeniz Technical University, BAP, Turkey (Ref. No. 2007.111.002.6)
Syntheses and biological activities of new hybrid molecules containing different heterocyclic moieties
No full textAlpay Karaoglu, Sengul/0000-0003-1047-8350WOS: 000325497500006PubMed: 240385194-Aryl-5-(pyridin-3-yl)-4H-1,2,4-triazole-3-(thi)oles 5-7, obtained starting from nicotinic acid hydrazide were converted to the corresponding Mannich bases 12-24 by the reaction with several heterocyclic amines in the presence of formaldehyde. The synthesis of S-alkylated compounds 8-11 was performed from the reaction of the corresponding triazol-5-thioles with various alkyl halides. The condensation of carbo(thio)amides 2-4 with 4-chlorophenacyl bromide afforded the corresponding 1,3-thia(oxa)zol-2(3H)-ylidene]pyridine-3-carbohydrazides 25-27. 1,3-Thia(oxa)zolidine derivatives 28-30 were obtained from the cyclization reaction between compounds 2-4 and ethyl bromoacetate. All newly synthesized compounds were screened for their antimicrobial, antiurease, and antilipase activities. The biological activity studies revealed that all the compounds screened showed good or moderate antimicrobial, antiurease, and/or antilipase activity.Karadeniz Technical University, BAP, TurkeyKaradeniz Teknik University [8623, 8663]The support provided by Karadeniz Technical University, BAP, Turkey (Ref. No. 8623 and 8663), is gratefully acknowledged
Antimicrobial and antiurease activities of newly synthesized morpholine derivatives containing an azole nucleus
No full textAlpay Karaoglu, Sengul/0000-0003-1047-8350WOS: 0003206732000092-[6-(Morpholin-4-yl)pyridin-3-ylamino]acetohydrazide (4) was obtained starting from 6-morpholin-4-ylpyridin-3-amine (2) via the formation of ester (3) and then converted to the corresponding Schiff bases (5, 6) with the reaction with aromatic aldehydes. The carbothioamide (9), obtained from the reaction of hydrazide with phenylisothiocyanate, was converted to the corresponding 1,2,4-triazole (11) and 1,3,4-thiadiazole (12) derivatives by the treatment with NaOH or H2SO4, respectively. The cyclocondenzation of 9 with 4-chlorophenacyl bromide or ethyl bromoacetate produced the corresponding 1,3-thiazole (10) or 1,3-thiazolidine derivatives (13), respectively. Antimicrobial and antiurease activities of newly synthesized compounds were investigated. Some of them were found to be active on M. smegmatis, and they displayed activity toward C. albicans and S. cerevisiae in high concentration. Compound 10 proved to be the most potent showing an enzyme inhibition activity with an IC50 = 2.37 +/- A 0.19 mu M
Biological evaluation and synthesis of new pyrimidine-2(1H)-ol/-thiol derivatives derived from chalcones using the solid phase microwave method
No full textAlpay Karaoglu, Sengul/0000-0003-1047-8350; YUCEL, TAYYIBE BEYZA/0000-0002-2632-8325WOS: 000431245300026Twenty-five new hydroxy- and methoxy-substituted 4,6-diarylpyrimidin-2(1H)-ol (20-34) and 4,6-diarylpyrimidine-2(1H)-thiol derivatives (35-44) were synthesized from the reaction of the corresponding 1,3-diaryl-2-propene-1-one compounds (1-19) with urea or thiourea using the solid-phase microwave method. All the new synthetic compounds (20-44) were evaluated with regard to their \g=a\-glucosidase activity. However, only compounds 22-25, 27, 31, 34, 35, 37, and 40 exhibited a greater inhibitory effect than standard acarbose. The IC50 values of the active compounds ranged between 2.36 and 13.34 mu M. The 25 new compounds were also screened for their in vitro pancreatic lipase activity and compounds 20-27 and 35-39 were found to be active. Of these compounds 26, 27, and 39 exhibited the best antilipase activities at concentrations of 0.40 +/- 0.06, 0.26 +/- 0.07, and 0.29 +/- 0.026 mu M. All the new compounds (20-44) were evaluated for their in vitro antimicrobial activity for nine test microorganisms. Compounds 20-24 and 35-39 were determined to possess a significant broad spectrum against the gram-positive bacteria Escherichia faecalis, Staphylococcus aureus, and Bacillus cereus among the tested bacterial agents. Compounds 20-24 and 35-39 exhibit the best activity against Mycobacterium smegmatis, with minimum inhibitory concentrations of 62.5-500 mu g/mL, indicating their potential use as antituberculous agents.Karadeniz Technical University Research Fund, Turkey [KTU-BAP-02 FHD5395]This study was supported by grants from Karadeniz Technical University Research Fund (KTU-BAP-02 FHD5395), Turkey
Synthesis and antimicrobial activity of new piperazine-based heterocyclic compounds
No full textAlpay Karaoglu, Sengul/0000-0003-1047-8350The hydrazide 5, that was obtained from -1-(4-fluorophenyl) piperazine (1), was converted to the cor-responding 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 formalde-hyde afforded the corresponding N-aminoalkylated tria-zoles 11-14. the effect of different catalysts and solvents on conventional and microwave (MW)-prompted reac-tions was examined. the synthesized compounds were screened for their antimicrobial activities.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [113Z181]; Karadeniz Technical University, BAP, TurkeyKaradeniz Technical University [8623]The support provided by Scientific and Technological Research Council of Turkey (TUBITAK, Project no: 113Z181) and Karadeniz Technical University, BAP, Turkey (Ref. No. 8623) is gratefully acknowledged
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 some hybrid molecules containing penicillanic acid or cephalosporanic acid moieties and investigation of their biological activities
No full textAlpay Karaoglu, Sengul/0000-0003-1047-8350Ethyl 4-amino-2-fluorophenylpiperazin-1-carboxylates containing a 1,3-oxazol(idin)e, 5-thioxo-1,2,4-triazole, 1,3,4-thiadiazole, 5-thioxo-1,3,4-oxadiazole, or 1,3-thiazole nucleus were obtained starting from ethyl piperazine-1-carboxylate (1) by several steps. the treatment of amine, 3 or hydrazide, 9 with several aromatic aldehydes generated the corresponding arylmethyleneamino (3a-f) or arylidenehydrazino (12a-c) compounds. the Mannich reaction between the 1,2,4-triazole or 1,3,4-oxadiazole compounds and 7-aca produced cephalosporanic acid derivatives. Penicillanic acid derivatives were obtained when 6-apa was used in the Mannich reactions. the synthesized compounds were screened for their antimicrobial, antilipase, and antiurease activities. Some of them were found to possess good-moderate antimicrobial activity against the test microorganisms. Two compounds exhibited antiurease activity, and four of them displayed antilipase activity.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [107T333]; Karadeniz Technical University, BAP, TurkeyKaradeniz Technical University [8623]This Project was supported by Scientific and Technological Research Council of Turkey (TUBITAK, Project No: 107T333) and Karadeniz Technical University, BAP, Turkey (Ref. No. 8623) and is gratefully acknowledged
Synthesis of some heterofunctionalized penicillanic acid derivatives and investigation of their biological activities
No full textAlpay Karaoglu, Sengul/0000-0003-1047-83506-Substituted amino-penicillanic acid esters were synthesized starting with 6-apa. the compounds containing a 1,3-thiazole- or 1,3-thiazolidinone nucleus linked to the penicillanic acid skeleton via a hydrazino linkage were obtained from 6-apa. the treatment of carbonylamino and carbonothioylamino compounds with 4-chlorophenacyl bromide or ethyl bromoacetate gave 6-bis{4-[1,3-thiazol(idinone)amino]benzoyl}amino derivatives of 6-apa. Benzyl derivatives were synthesized in several steps, starting with 4-aminobenzoyl chloride. the treatment of 4-{[3-benzyl-4-oxo-1,3-thia(oxa)zolidin-2-ylidene]amino}benzoyl chlorides with 6-apa in ethanolic solution produced the 6-[bis(4-{[3-benzyl-4-oxo-1,3-thiazolidin-2-ylidene]amino}benzoyl)amino] derivative of penicillanic acid, while the reaction of the same intermediates in DMF gave the mono-substituted amino derivative of 6-apa. the synthesized compounds were screened for their biological activities, and some of them were found to possess good to moderate antimicrobial activity. Moreover, some of the compounds displayed antiurease, anti--lactamase, and/or antilipase activities.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111T427]The support provided by Scientific and Technological Research Council of Turkey (TUBITAK, Project no: 111T427) is gratefully acknowledged
Biological activity and characterization of volatile compounds of teucrium orientale var. Glabrescens by SPME and GC-FID/MS
No full textEYUPOGLU, Ozan Emre/0000-0002-4449-0537; Alpay Karaoglu, Sengul/0000-0003-1047-8350This study describes the constituents of phenolic acids, volatile components, antioxidant and antimicrobial activities of Teucrium orientale var. glabrescens. Antioxidant activity of methanolic and aquous extracts were examined by three different methods, namely ferric reducing antioxidant power, cupric reducing antioxidant capacity and 2,2-diphenylpicrylhydrazyl radical scavenging activity. the phenolic constituents were also determined by reverse phase-high performance liquid chromatography. Solid phase microextraction of Teucrium orientale var. glabrescens was analyzed by Gas Chromatography-Flame Ionization Dedector/Mass Spectromerty, Solid-Phase Microextraction (GC-FID/MS, SPME). the antimicrobial activity was studied by agar diffusion method. Extracts showed strong antioxidant and antimicrobial activity and contained large amounts of antioxidant compounds. Rosmarinic acid, p-coumaric acid and p-hydroxybenzoic acid were detected in methanolic extract of plant. Aquous extract was especially effective against Mycobacterium smegmatis. the main chemical classes identified consisted of aldehydes (32.5%), hydrocarbons (29.8%) and monoterpene hydrocarbons (29.8%). Common volatile components of plant detected included nonanal, thuja-2,4 (10)-diene and tetracosane
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