Hayriye Genç

In vitro effect of novel β-lactam compounds on xanthine oxidase enzyme activity

Abstract Carbazole substituted imines (2a-l) were prepared from N-methyl-3-amino carbazole with different aldehydes. The imines compounds undergo (2+2) cycloaddition reactions with in situ ketenes to produce β-lactam compounds (3a-l). The β-lactam compounds were tested as inhibitors of the xanthine oxidase (XO) purified from bovine milk. The results show that these compounds exhibit inhibitory effects on XO at low concentrations with IC50 values ranging from 21.65 to 58.04 µM. The most effective compound for XO was 4-(4-chlorophenyl)-1-(9-ethyl-9H-carbazol-3-yl)-3-phenylazetidin-2-one with IC50 of 21.65 μM. The lactams investigated here showed effective XO inhibitory effects, in the same range as the clinically used allopurinol.

In vitro inhibition of polyphenol oxidase by some new diarylureas.

A new series of N,N′-diarylureas (1–9) was synthesized. These compounds were investigated as inhibitors of polyphenol oxidase (PPO) which had been purified from banana by an affinity gel comprised of Sepharose 4B-l-tyrosine-p-amino benzoic acid. Ki values for (1), (2), (3), (5), (6), (7) and (8) were determined as 0.285, 17.97, 0.187, 0.108, 0.063, 0.044 and 0.047 mM, respectively. Thus (2) was by far the most effective inhibitor. Interestingly, (4) and (9) behaved as an activator of PPO in this study.

Synthesis and tyrosinase inhibitory properties of novel isoquinoline urea/thiourea derivatives

Abstract A new series of isoquinoline urea/thiourea derivatives (1–11) were synthesized, and their inhibitory effects on tyrosinase were evaluated. Isoquinoline urea/thiourea derivatives were obtained as a result of the reaction of 5-aminoisoquinoline with isocyanates or isothiocyanates. The result showed that all the synthesized compounds inhibited the tyrosinase enzyme activity. Among the compounds synthesized, 1-(4-chlorophenyl)-3-(isoquinolin-5-yl)thiourea (3) was found to be the most active one (Ki = 119.22 μM), and the inhibition kinetics analyzed using Lineweaver–Burk double reciprocal plots revealed that compound 3 was a competitive inhibitor. We also calculated HOMO-LUMO energy levels, some selected the synthesized compounds (1, 4, 11, 3, 6, 2) using Gaussian software.

Hydrogenation of Some Vegetable Oils by Scrap Automobile Catalyst

Some vegetable oils were hydrogenated with scrap automobile catalyst (SAC) as a catalyst. The optimum reaction conditions (solvent, reaction time, and catalyst amount) were determined. Our results showed that the linoleic acid was reduced to elaidic acid in the sunflower oil. This procedure not only gives high yields but also allows recycling of automobile wastes as a catalyst in organic reactions and is representative of green chemistry.

Novel thymol bearing oxypropanolamine derivatives as potent some metabolic enzyme inhibitors – Their antidiabetic, anticholinergic and antibacterial potentials

A series of classical and newly synthesized thymol bearing oxypropanolamine compounds were synthesized and characterized. Their in vitro antibacterial activity on A. baumannii, P. aeruginosa, E. coli and S. aureus strains were investigated with agar well diffusion method. The results were compared with commercially available drug active compounds. As well as 3a, 3b and 3c have the most significant antibacterial effect among all the tested compounds; approximately all of them have more antibacterial activity than the reference drugs. These novel thymol bearing oxypropanolamine derivatives were effective inhibitors of the α-glycosidase, cytosolic carbonic anhydrase I and II isoforms (hCA I and II), and acetylcholinesterase enzymes (AChE) with Ki values in the range of 463.85-851.05 µM for α-glycosidase, 1.11-17.34 µM for hCA I, 2.97-17.83 µM for hCA II, and 13.58-31.45 µM for AChE, respectively.

Naftaleniloksipropanol türevi bazı bileşiklerin çok ilaca dirençli bakterilere karşı in vitro etkinliklerinin incelenmesi

Coklu ilaca direncli bakterilerin tedavisi butun dunya icin ciddi bir problem teskil etmekte ve yeni antibakteriyellere olan ihtiyac gun gectikce artmaktadir. Bu calismada, α-Naftol bilesiginden o ksipropanolamin turevleri sentezlenmis ve CID (coklu ilaca direncli) bakterilere karsi aktiviteleri degerlendirilmistir. Gram-pozitif bakterilerden Staphylococcus aureus ve Gram-negatif bakterilerden A. baumannii, P. aeruginosa, E. coli suslari kullanilmistir. Calismada kullanilan 2a-d bilesiklerinin sentezi icin ilk olarak α-naftol ile epiklorohidrin reaksiyona sokularak 2-((naftelen-1-iloksi)metil)oksiran (1) bilesigi elde edilmis ve ardindan dort degisik amin turevi ile reaksiyona sokularak 2a-d turevleri elde edilmistir. Bu bilesiklerin CID bakterilere karsi in vitro etkinlikleri Kirby-Bauer metodu ile CLSI standartlarina gore belirlenmistir. Elde edilen bilesiklerden 2a, 2b ve 2c her bir bakteri turune karsi test edilen diger antibakteriyellerden daha fazla antibakteriyel etkiye sahipken, 2d bilesigi Gram-negatif bakterilere karsi ortalama veya altinda bir etkinlik gostermis, Gram-pozitif bakteri olan S. aureus ’ a karsi yuksek bir etkinlik sergilemistir.

The Antibacterial Activity of 2-aminoindanbiguanide Chloride and Acetate Salts against Resistant Gram-negative Bacilli

Antiseptics and disinfectants are important substances for medical care. However, the needs for new antiseptics have increased in the last few years, due to multi-drug resistant pathogens. In this study we aimed to evaluate, the efficacy of 2-aminoindanbiguanide chloride (2-AIB.HCI) and 2-aminoindanbiguanideacetate (2-AIB.HOAc) salts that were synthesized against multi-drug resistant Gram-negative bacilli (MDR-GNB) (Acinetobacter spp, Escherichia coli and Klebsiella pneumoniae). According to our resultsat70 mg/mL concentrations of 2-AIB.HCI and 2-AIB.HOAc salts have been confirmed to be effective against hospital infection causing MDR-GNB. It was shown that 2-AIB.HCI and 2AIB.HOAc salts have antibacterial efficacy against MDR-GNB.