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Öğe 3a-Bromo-perhydro-2,6a-epoxy-oxireno[e][2]benzofuran(International Union of Crystallography, 2007) Koşar, Başak; Karaarslan, Muhsin; Demircan, Aydın; Büyükgüngör, OrhanIn the title compound, C8H9BrO3, the boat form of the six-membered ring is almost symmetrical with respect to the epoxy bridge. The two five-membered rings generated by the epoxy bridge of the six-membered ring adopt envelope conformations, whereas the third five-membered ring adopts a half-chair conformation. The refinement results suggest partial inversion twinning.Öğe A new method for fast chitin extraction from shells of crab, crayfish and shrimp(Taylor & Francis Ltd., 2015) Kaya, Murat; Baran, Talat; Karaarslan, MuhsinA new method for quick chitin isolation from the shells of crab, crayfish and shrimp is described. The main difference between the new method and the conventional method is two sodium hypochlorite (NaClO) treatments for 10min each before the processes of demineralisation and deproteinisation. After the NaClO treatment, only 15min is adequate for the demineralisation and 20min for the deproteinisation processes. Newly extracted chitin from crab, crayfish and shrimp shells and commercial chitin were characterised using FT-IR, TGA, X-ray diffractometry and elemental analysis. From the results, it was observed that the chitins isolated with the new method and the commercial chitin had almost the same physicochemical properties. The advantage of the new method compared to traditional methods is the relatively rapid chitin extraction. When compared to the traditional chitin extraction method, the proposed method appears to be promising regarding its time and energy saving nature.Öğe One-pot cascade synthesis of fused nitrogen-containing heterocycles in aqueous media - utility of n -protective groups in ıntramolecular diels-alder reaction of furan(Georg Thieme Verlag, 2016) Demircan, Aydın; Kandemir, Muhammet Kasım; Çolak, Medine; Karaarslan, MuhsinA metal-free, thermal, intramolecular Diels-Alder (IMDA) reaction of furan in aqueous media without the use of microwave irradiation was investigated. Protection of the amine functionality and the cycloaddition reaction were performed as a one-pot, two-component process. Various nitrogen-protecting groups and their electronic and steric effects on the cycloaddition reaction were studied. The protection-intramolecular Diels-Alder reaction sequence proceeds under environmentally benign aqueous conditions, which are tolerated by substrates with a broad range of nitrogen-protecting groups such as benzyloxycarbonyl (Cbz), trityl, tert-butoxycarbonyl (Boc), trifluoroacetyl, tosyl, mesyl, and p-nosyl [(4-nitrophenyl)sulfonyl]. This study allowed the development of a stereoselective, tandem allylamine isomerization-Diels-Alder cycloaddition sequence leading to the rapid assembly of complex nitrogen-containing heterocycles in a simple one-pot process.Öğe Studies on the heavy metal removal efficiency and antibacterial activity of 2-(diphenylphosphino)aminopyridine(Macedonian Journal of Chemistry and Chemical Engineering, 2018) Sarıöz, Özlem; Malgaç, Burcu; Sürme, Yavuz; İlk, Sedef; Karaarslan, MuhsinThe solvent extraction of metal picrates such as Ni2+, Cu2+, Co2+, Pb2+ and Cd2+ from the aqueous to the organic phase was studied using 2-(diphenylphosphino)aminopyridine (Ph2PNHpy). The effects of parameters including the pH of the aqueous phase and the ligand solution volume were investigated to de-termine the extraction ability of the ligand for metal ions. The results showed that the extraction percent-ages of metal ions were high at low pH values. The antibacterial activity of the aminophosphine was also screened against Escherichia coli (E. coli) ATCC 25922, Staphylococcus aureus (S. aureus) ATCC 25923, Pseudomonas syringae pv. tomato (P. syringae) DC300, Salmonella enterica serotype Typhmuri-um (S. typhmurium) SL 1344 and Streptococcus mutans (S. mutans) ATCC 25175. From the studies of antibacterial activity, it was observed that the ligand exhibited a potent inhibitory effect against all Gram-negative and Gram-positive bacteria with a diameter of inhibition zone ranging from 3.86 to 18.10 mm. The aminophosphine ligand (Ph2PNHpy) should be considered as a suitable bio-active molecule for anti-microbial material design and next-generation, non-toxic drug fabrication. The Ph2PNHpy obtained may have the potential for use as an antimicrobial additive for bioengineering applications. © 2018 özlem Sariöz, Burcu Malgaç, Yavuz Sürme, Sedef Ilk, Muhsin Karaarslan.Öğe Subtractive-FTIR spectroscopy to characterize organic matter in lignite samples from different depths(PERGAMON-ELSEVIER SCIENCE, 2012) Gezici, Orhan; Demir, İbrahim; Demircan, Aydın; Ünlü, Nuri; Karaarslan, MuhsinOrganic matter present in lignite samples collected from different depths (i.e. top, mid and bottom) of lignite source. Ilgin, Konya province, was examined by using subtractive-FTIR-ATR spectroscopy. FTIR spectra were recorded on (i) original samples, (ii) the samples dried at 105 degrees C and (iii) the samples acid-treated and dried. After a combustion process performed for each sample at 650 degrees C for 15 min, the spectra of samples were recorded and subtracted from the spectra of untreated samples. Hence, a software-based subtraction made it possible to acquire a representative spectra related with organic matter. As the contribution of the bands related with inorganic constituents in lignite samples were eliminated after spectrum-subtraction procedure, difference-spectra led analyzing the spectra related with organic matter in lignite samples, reasonably. Furthermore, the bands related with acidic functional groups, aromatic and aliphatic structures were analyzed on the basis of difference-spectra, easily. From the difference-spectra it was shown that an acid-treatment process under mild conditions caused shift in some specific bands related with carbonyl groups of carboxyls so that the band at around 1710 cm(-1) arisen, while the intensity of the band at around 1420 cm(-1) was diminished. Through the acid-treatment process, acidic groups in lignite samples from different depths were thought to be turned into similar forms by protonation and/or stripping of metal ions originally bonded. Difference-spectra acquired for acid-treated samples made it possible to evaluate the form of carboxylic acid groups present in the studied samples under specific environmental conditions. Hence, a facile and environmentally-friendly methodology was used to analyze organic matter in lignite by using FTIR spectra, and valuable information was acquired about the aliphatic, aromatic and acidic character of the studied lignite samples collected from different depths. The proposed methodology seems to be promising in acquiring approximate representative spectra for lignite organic matter by using little or no chemicals.Öğe Synthesis and characterization of novel chiral (1r,2r)-1,2-bis[5-(aminomethylphospinic acid)-1,3,4-thiadiazol-2-yl]ethane-1,2-diols(Taylor & Francis Ltd, 2012) Koparir, Pelin; Karaarslan, Muhsin; Örek, Cahit; Koparır, Metin(1R,2R)-1,2-bis[5-(arylideneamino)-1,3,4-thiadiazol-2-yl]ethane-1,2-diol (2a-d) were synthesized by using appropriate aldehydes and (1R,2R)-1,2-bis(5-amino-1,3,4-thiadiazol-2-yl)ethane-1,2-diol (1) as a starting compound. Then, the phosphinic acid component (3a-d) were obtained from (2a-d) and hypophosporus acid. In addition, the structures of the novel chiral compounds (2a-d) and (3a-d) were confirmed by elemental analyses, IR, H-1-NMR, C-13-NMR, and P-31-NMR spectra. H-1 NMR and C-13 NMR spectra for 1, 2a, and 3a (Figures S1-S6) are available online in the Supplemental Materials.Öğe Synthesis and in-vitro antimicrobial activity of novel aminophosphinic acids containing cyclobutane and 1,3-thiazole(Taylor & Francis, 2011) Koparır, Pelin; Karaarslan, Muhsin; Örek, Cahit; Koparır, MetinThe compounds {[4-(3-methyl-3-aryl(mesityl-phenyl-tetralino)cyclobutyl)-1,3-thiazol-2-yl]amino}(aryl)methyl-phosphinic acids 2a-l were prepared by condensation of 2-amino-4-(3-aryl(mesityl-phenyl-tetralino)-3-methylcyclobutyl)thiazoles 1a-c with various aromatic aldehydes and hypophosphorous acid through a one-pot reaction. The characterizations of these compounds were obtained by elemental analyses, infrared (IR) spectra, and H-1, C-13, and P-31 NMR (nuclear magnetic resonance) techniques. The synthesized compounds were tested in vitro against one Gram-positive and two Gram-negative bacterial strains, one mycobacterial strain, and a fungus Candida albicans. Compound 2f showed significant activity against Staphylococcus aureus, whereas the others had no remarkable activity on this strain. Compound 2g was found to be more active than the others against Mycobacterium fortuitum at an MIC (minimum inhibitory concentration) value of 32 mu g/mL. The antibacterial and antifungal activities of 2a-l were also compared with various standard drugs.Öğe Tert-Butyl 3a-chloro-2-methylperhydro-2,6a-epoxyoxireno[e]isoindole-5-carboxylate(International Union of Crystallography, 2007) Koşar, Başak; Karaarslan, Muhsin; Yıldız, Yaşar Kemal; Demircan, Aydın; Büyükgüngör, OrhanIn the title compound, C14H20ClNO4, the mol-ecules are linked only by weak van der Waals inter-actions, and the three five-membered rings adopt envelope conformations.Öğe Tert-Butyl 3a-chloroperhydro-2,6a-epoxyoxireno[e]isoindole-5-carboxylate(International Union of Crystallography, 2007) Koşar, Başak; Karaarslan, Muhsin; Demir, İbrahim; Büyükgüngör, OrhanIn the title compound, C13H18ClNO4, the mol-ecules are linked only by weak van der Waals inter-actions. The boat form of the six-membered ring is almost symmetric with respect to the ep-oxy bridge. The three five-membered rings adopt envelope conformations.Öğe The electronic effect of N-protecting groups on Diels–Alder cycloaddition reaction of furan-cored compounds(Springer Verlag, 2019) Karaarslan, Muhsin; Cansu, FatmaFuran-derived nitrogen side-chain molecules were used to investigate the effect of nitrogen-protecting groups on intramolecular Diels–Alder cyclization reaction yields. The protection reactions were carried out in both dichloromethane and water. The protected molecules were synthesized in dichloromethane and then cycled in toluene. On the other hand, in water as a reaction media both protection and cyclization were carried out in the same environment which provides advantages in saving time and chemicals. To study the electronic effects of protecting groups, various electron-withdrawing and electron-donating protective groups were used and their effects on cyclization were evaluated. As a result, the mesomeric electron-withdrawing and sterically large protecting groups increased the yield of Diels–Alder cycling reactions effectively. In addition, the iminium ion formed between some protecting groups and the molecule caused the formation of E/Z isomers and this was demonstrated by dynamic NMR experiments. © 2019, Iranian Chemical Society.Öğe The quick extraction of chitin from an epizoic crustacean species (Chelonibia patula)(TAYLOR & FRANCIS, 2014) Kaya, Murat; Karaarslan, Muhsin; Baran, Talat; Can, Esra; Ekemen, Gülçin; Bitim, Betül; Duman, FatihChitin was isolated from the shells of Chelonibia patula (barnacle, Crustacea), which lives on blue crab epizoically, following a 10-min demineralisation process through HCl and a 20-min deproteinisation process through NaOH. Due to the low-crystalline structure, and mineral-rich and low-protein content of the shells, chitin isolation was convenient. It was observed that the shell structure of C. patula contains 3.11% chitin per its dry weight. Following characterisation of the isolated chitin by using Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffractometry, elemental analysis and scanning electron microscopy, it was determined that there was close similarity with the a-chitin isolated from crabs, shrimps and insects in various studies. It was observed that chitin was composed of nanofibres with a width of 10-20 nm. It was concluded that this was an economically advantageous chitin resource compared with crustaceans such as shrimp, crayfish and crab, because it is possible to isolate chitin in a significantly shorter time.
