[Show abstract][Hide abstract] ABSTRACT: In vitro inhibition effects of indolylchalcones and new pyrido[2,3-d]pyrimidine derivatives on purified human carbonic anhydrase I and II (hCA I and II) were investigated by using CO2 as a substrate. The results showed that all compounds inhibited the hCA I and hCA II enzyme activities. Among all the synthesized compounds, 7e (IC50 = 6.79 µM) was found to be the most active compound for hCA I inhibitory activity and 5g (IC50 = 7.22 µM) showed the highest hCA II inhibitory activity. Structure-activity relationships study showed that indolylchalcone derivatives have higher inhibitory activities than pyrido[2,3-d]pyrimidine derivatives on hCA I and hCA II. Additionally, methyl group bonded to uracil ring increases inhibitory activities on both hCA I and hCA II.
BioMed Research International 08/2014; 2014:594879. DOI:10.1155/2014/594879 · 3.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A newly series of isatin derivatives (6a-t) containing alkyl/aryl urea groups were synthesized and their inhibitory effects on the diphenolase activity of banana tyrosinase were evaluated. Tyrosinase was purified from banana on an affinity gel comprised of Sepharose 4B-L-tyrosine-p-aminobenzoic acid. The results showed that all the synthesized compounds inhibited the tyrosinase enzyme activity. Among them, 1-(2,3-dioxoindolin-5-yl)-3-(4-nitrophenyl)urea (6l) was found to be most active compound (Ki = 24.96 µM). The inhibition kinetics was analysed by Lineweaver-Burk double reciprocal plots. It revealed that compound 6l was a competitive inhibitor. According to results of structure-activity relationship, generally, the compounds electron-donating group bonded to the phenyl ring have higher inhibitory activity against tyrosinase than halogen group bonded to the phenyl ring. The inhibitory activities of alkyl urea substituted compounds decreased with increasing carbon number of the alkyl groups at urea moiety. The halogen series at the para position of the phenyl ring showed a qualitative relationship for higher inhibitory activity with increasing size and polarizability. HOMO-LUMO energy levels and dipole moments of some selected compounds (6a, 6d, 6h, 6l and 6o) were also calculated by Gaussian software.
Current Topics in Medicinal Chemistry 05/2014; 14(12). DOI:10.2174/1568026614666140530104344 · 3.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We have succeeded in total synthesis of apigenin 7-O-β-D-cellobioside (1a) and apigenin 7-O-β-D-cellobiosyl-4′-O-β-D-glucopyranoside (1c) via four and six steps in a total yield of 56 and 76 % from naringenin (2), respectively. We also synthesized apigenin 7-O-β-D-glucopyranoside (1b) and apigenin 7,4′-di-O-β-D-glucopyranoside (1d) from naringenin (2). We also examined two monoglycoside and two diglycoside with polyphenol oxidase (PPO) from potato (Solanum tuberosum ). The result showed that 1a inhibited the polyphenol oxidase enzyme activity. The value of IC50 was 1.08 mM. 1b was activator effect on polyphenol oxidase enzyme activity. On the other hand, apigenin 7,4′-di-O-glycosides (1c-d) showed no activator and inhibitor effect on polyphenol oxidase enzyme activity.
Asian Journal of Chemistry 01/2014; 26(23). DOI:10.14233/ajchem.2014.18034 · 0.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abstract In this study, in vitro inhibitory effects of some saccharin derivatives on purified carbonic anhydrase I and II were investigated using CO(2) as a substrate. The results showed that all compounds inhibited the hCA I and hCA II enzyme activities. Among the compounds, 6-(p-tolylthiourenyl) saccharin (6m) was found to be the most active one for hCA I activity (IC(50) = 13.67 μM) and 6-(m-methoxyphenylurenyl) saccharin (6b) was found to be the most active one for hCA II activity (IC(50) = 6.54 μM). Structure-activity relationships (SARs) study showed that, generally, thiourea derivatives (6l--v) inhibited more hCA I and hCA II than urea derivatives (6a-k). All compounds (excluding 6c and 6r) have higher inhibitory activity on hCA II than on hCA I.
Journal of Enzyme Inhibition and Medicinal Chemistry 01/2013; 29(1). DOI:10.3109/14756366.2012.757222 · 2.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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.
[Show abstract][Hide abstract] ABSTRACT: Selective and synergistic extraction of cadmium from acidic iodine solutions containing Cd2+, Co2+ and Ni2+using solvent extraction (SX) technique is presented in this study. The study has highlighted the importance of main and synergistic extractants composition. The mixtures have evident synergistic effects on Cd2+ with a synergistic enhancement factor of 2.22. The various experimental parameters were studied to determine the optimum extraction and stripping conditions of Cd2+. Under optimum conditions, the maximum extraction efficiency (99.7%) was achieved when using 1.5% (v/v) TIOA and 0.5% (v/v) TBP in dichloromethane within 5 min. Extracted Cd2+ was stripped effectively from the organic phase using 2.0 mol/L NaOH solution.
Journal of Industrial and Engineering Chemistry 07/2012; 18(4):1286–1292. DOI:10.1016/j.jiec.2012.01.025 · 3.51 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The first total synthesis of apigenin 7-O-β-D-cellobioside (5) and apigenin 7-O-β-D-cellobiosyl-4'-O-β-D-glucopyranoside (8), which were isolated from petals of Salvia patens and Salvia uliginosa, were achieved in four and six steps and 76% and 57%, respectively, overall yield, from naringenin (1). The total synthesis contained two-glycosylation, acetylation, oxidation, selective deacetylation and deprotection steps. Although this route contained six steps, the targeted compounds were obtained with higher yields and easier purifications than other synthetic methods.
Natural product research 05/2012; 27(7). DOI:10.1080/14786419.2012.686908 · 0.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An alternative method has been developed for the anomeric deacetylation of fully acetylated carbohydrate derivatives using zinc acetate dihydrate as a catalyst in methanol under mild conditions. The experimental simplicity, low cost, acceptable yield, use of a readily handled acidic catalyst, and the environmentally benign nature are some of the advantages of this method.
Chemical Papers- Slovak Academy of Sciences 04/2012; 66(4). DOI:10.2478/s11696-012-0143-5 · 1.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A newly series of 6-(phenylurenyl/thiourenyl) saccharin (6a-y) derivatives were synthesized and their inhibitory effects on the diphenolase activity of banana tyrosinase were evaluated. A 70-fold purification of the enzyme with 6.85% yield was achieved by using a Sepharose 4B-l-tyrosine-p-amino benzoic acid affinity column. The result showed that all the synthesized compounds inhibited the tyrosinase enzyme activity. Among the compounds synthesized, 6-(3-iodophenylthiourenyl) saccharin (6s) was found to be most active one (K(i)=3.95 μM) and the inhibition kinetics analyzed by Lineweaver-Burk double reciprocal plots revealed that compound 6s was a competitive inhibitor. Structure-activity relationships study showed that generally, most of the 6-(phenylthiourenyl) saccharin derivatives (6m-y) exhibited higher inhibitory activity than 6-(phenylurenyl) saccharin derivatives (6a-l). An electron-withdrawing group at 3-position of phenylurenyl-ring increased in activity and the halogen series at 3-position of phenylthiourenyl-ring showed a qualitative relationship for higher inhibitory activity with increasing size and polarizability. We also calculated HOMO-LUMO energy levels and dipole moments of some selected the synthesized compounds (6a, 6h, 6m and 6s) using Gaussian software.
[Show abstract][Hide abstract] ABSTRACT: Radical oxidation and addition reactions of anthracene (1), 9-methylanthracene (2) and 9-phenylanthracene (3) were investigated with dimethyl malonate (4) in the presence of ceric ammonium nitrate (CAN) and manganese(III) acetate (Mn(OAc) 3). Although mostly anthraquinone derivatives and bianthrone were obtained with CAN, substituted 9,10-dihydroanthracene and 9,10-substituted anthracene derivatives were obtained with Mn(OAc) 3. Dimethylmalonyl addition products (5a, 33 % and 5b, 42 %) were obtained in higher yield than quinones (5d, 8 % and 5e, 3 %) using Mn(OAc) 3 as oxidant. 9a (96 %) and 9b (84 %) were synthesized in high yield and substitution products (7a, 44 % and 8b, 56 %) were obtained in higher yields than quinones (5d and 5e) using CAN as oxidant. The reactions were carried out in non-acidic medium (dichloromethane and methanol). Based on the structures of the isolated products a mechanism for these transformations was proposed.
Macedonian Journal of Chemistry and Chemical Engineering 01/2012; 31(1). · 0.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A newly series of 4-(phenylurenyl)chalcone (4a-j) and 4'-(phenylurenyl/thiourenyl)chalcone (9a-l) derivatives were synthesized and their inhibitory effects on the diphenolase activity of banana tyrosinase were evaluated. Tyrosinase has been purified from banana on an affinity gel comprised of Sepharose 4B-l-tyrosine-p-aminobenzoic acid. The result showed that 4a-j inhibited the PPO enzyme activity. Conversely, 9a-h and 9i-l showed activator effect on tyrosinase enzyme activity.