In vitro α-glucosidase, docking and density functional theory studies on novel azide metal complexes.

Aim: The goal of this study is to synthesize new metal complexes containing N-methyl-1-(pyridin-2-yl)methanimine and azide ligands as α-glucosidase inhibitors for Type 2 diabetes. Materials & methods: The target complexes (12-16) were synthesized by reacting N-methyl-1-(pyridin-2-yl)methanimine (L1) with sodium azide in the presence of corresponding metal salts. The investigation of target protein interactions, vibrational, electronic and nonlinear optical properties for these complexes was performed by molecular docking and density functional theory studies. Results: Among these complexes, complex 13 (IC50 = 0.2802 ± 0.62 µM) containing Hg ion showed the highest α-glucosidase inhibitory property. On the other hand, significant results were detected for complexes containing Cu and Ag ions. Conclusion: Complex 13 may be an alternate anti-diabetic inhibitor according to in vitro/docking results.

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Evaluation of cytotoxic and antioxidant potential of Dittrichia viscosa (L.) Greuter used in traditional medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: Dittrichia viscosa (L.) Greuter ("Sari ot, Yapiskan andiz otu" in Turkish) is a medicinal plant that has been traditionally used in the Mediterranean area. This plant is used by the local population for the treatment of cancer. Investigation of their biological activities is therefore very important to be supported by scientific basis for traditional use. AIMS OF THE STUDY: In this study, it is aimed to assess the phytochemical composition, in vitro antioxidant, cytotoxic, and antiproliferative activities of the aqueous and ethanolic extracts obtained from the aerial parts (stems, leaves, flowers) of D. viscosa, collected from two sites in Turkey (Istanbul and Marmaris) against breast and prostate tumor cell lines. MATERIALS AND METHODS: Validated methods were used to evaluate the in vitro antioxidant capacity (DPPH, ABTS, CUPRAC), cytotoxicity (Cell Viability Assay), antiproliferative (Apoptosis assay), and phytochemical compositions. The nepetin (N), 3-O-methylquercetin (Q), and hispidulin (H) in the extracts of D. viscosa were quantified by HPLC and LC-HRMS. Furthermore, in order to control the standards of benefiting from the plant in a healthy way, the contents of some heavy metals were also assessed by ICP-OES in the plant and soil samples as well as the species soil's physical and chemical characteristics. RESULTS: We have found that heavy metal accumulation in the soil does not exceed the allowable limit value except for the nickel. The results showed that ethanol extraction is an efficient strategy to get NQH molecules with a higher content compared with other extraction techniques. However, using the same extraction method revealed that the amount of NQH molecules in the samples of two different regions were variable. The results suggested that all extracts had a high amount of total phenolic content (12.354-22.184 µg GAE/mg) and total flavonoid content (4.442-17.263 µg QE/g). In the antioxidant assay according to the DPPH method, the aqueous ethanol extracts (IC50; 21.00 µg/mL) showed stronger antioxidant activity than BHT. A significant reduction in cell viability was particularly observed in MDA-MB-231 cells, which were sensitive to ethanolic extracts in Istanbul (12-22%) and in Marmaris (14-15%), while PC3 cell lines were also more sensitive to extracts of the aqueous in Istanbul (16%) and the decoction in Marmaris (12%) after 72 h. Especially, it was observed that Marmaris and Istanbul samples induced the toxicity against PC3 cells. CONCLUSION: The study supports the medicinal use of D. viscosa as a potential anticancer against breast and prostate cancer cells in vitro and underlines the immense therapeutic potential of the plant.

Synthesis, biological activity and multiscale molecular modeling studies of bis-coumarins as selective carbonic anhydrase IX and XII inhibitors with effective cytotoxicity against hepatocellular carcinoma.

A series of novel bis-coumarin derivatives containing triazole moiety as a linker between the alkyl chains was synthesized and their inhibitory activity against the human carbonic anhydrase (hCA) isoforms I, II, IX and XII were evaluated. In addition, cytotoxic effects of the synthesized compounds on renal adenocarcinoma (769P), hepatocellular carcinoma (HepG2) and breast adeno carcinoma (MDA-MB-231) cell lines were examined. While the hCA I and II isoforms were inhibited in the micromolar range, the tumor-associated isoform hCA IX and XII were inhibited in the high nanomolar range. 4-methyl-7-((1-(12-((2-oxo-2H-chromen-7-yl)oxy)dodecyl)-1H-1,2,3-triazol-4-yl)methoxy)-2H-chromen-2-one (5p) showed the strongest inhibitory activity against hCA IX with the Ki of 144.6 nM and 4-methyl-7-((1-(10-((2-oxo-2H-chromen-7-yl)oxy)decyl)-1H-1,2,3-triazol-4-yl)methoxy)-2H-chromen-2-one (5n) exhibited the highest hCA XII inhibition with the Ki of 71.5 nM. In order to better understand the inhibitory profiles of studied molecules, multiscale molecular modelling approaches were applied. Low energy docking poses of studied molecules at the binding sites of targets have been predicted. In addition, electrostatic potential surfaces (ESP) for binding sites were also generated to understand interactions between proteins and active ligands.

Synthesis, antioxidant activity and SAR study of novel spiro-isatin-based Schiff bases.

A new series of 21 Schiff bases of spiro-isatin was synthesized, and their DPPH, CUPRAC and ABTS cation radical scavenging abilities were investigated for antioxidant activity. The results showed that all the synthesized compounds exhibited antioxidant activity for each assay. 5̍-(2,3-Dihydroxybenzylideneamino)spiro[[1,3] dioxolane-2,3̍-indoline]-2̍-on (5c) (IC50 = 4.49 µM, for DPPH; IC50 = 0.39 µM, for ABTS.+; and A0.50 = 0.42 µM, for CUPRAC) showed significantly better ABTS, CUPRAC and DPPH radical scavenging ability than quercetin (IC50 = 8.69 µM, for DPPH; IC50 = 15.49 µM, for ABTS.+; and A0.50 = 18.47 µM, for CUPRAC), which is used as a standard. SAR study showed that the synthesized compounds had higher ABTS.+ activity than DPPH and CUPRAC activities. Moreover, the compounds (5c and 5d), containing two hydroxyl groups, exhibited the highest antioxidant activities for all assays. Quantum chemical calculations were also carried out to support SAR results.

Anticholinesterase, Antioxidant, Antiaflatoxigenic Activities of Ten Edible Wild Plants from Ordu Area, Turkey.

Turkey has highly rich floras of medicinal and aromatic plants because of having various climate conditions in different regions. One of these regions is Middle Black Sea Region, especially Ordu Province. Extracts of 10 edible plants (Arum maculatum L., Hypericum orientale L., Ornithogalum sigmoideum Freyn et Sint., Silene vulgaris Garcke var. macrocarpa, Plantago lanceolata L., Achillea millefolium L. subsp. pannonica, Rumex crispus L., Rumex acetosella L., Capsella bursa-pastoris L., Coronopus squamatus Asch.), grown in Ordu, Turkey, were prepared with different solvents (hexane, ethanol and water, separately) and their anticholinestrase and antiaflatoxigenic activities were evaluated. Additionally, the cupric reducing antioxidant capacities (CUPRAC) and ABTS cation radical scavenging abilities of the extracts were assayed. The ethanol extract of R. acetosella exhibited the highest antioxidant activity (A0.5 value of 25.31 µg/mL, for CUPRAC activity; IC50 value of 23.73 µg/mL, for ABTS activity). The hexane extract of C. bursa-pastoris showed the strongest inhibition against AChE enzyme with IC50 value of 7.24 µg/mL, and the hexane extract of A. millefolium subsp. pannonica had the highest BChE activity with IC50 value of 6.40 µg/mL. The ethanol extract of P. lanceolata exhibited the strongest inhibition against aflatoxin with 88% inhibition.

Synthesis, anticholinesterase activity and molecular modeling study of novel carbamate-substituted thymol/carvacrol derivatives.

New thymol and carvacrol derivatives with the carbamate moiety were synthesized and their inhibitory effects on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were evaluated. 5-isopropyl-2-methylphenyl(3-fluorophenyl)carbamate (29) was found to be the most potent AChE inhibitor with IC50 values of 2.22µM, and 5-isopropyl-2-methylphenyl (4-fluorophenyl)carbamate (30) exhibited the strongest inhibition against BuChE with IC50 value of 0.02µM. Additionally, the result of H4IIE hepatoma cell toxicity assay for compounds 18, 20, 29, 30 and 35 showed negligible cell death at 0.07-10µM. Moreover in order to better understand the inhibitory profiles of these molecules, molecular modeling studies were applied. Binding poses of studied compounds at the binding pockets of AChE and BuChE targets were determined. Predicted binding energies of these compounds as well as structural and dynamical profiles of molecules at the target sites were estimated using induced fit docking (IFD) algorithms and post-processing molecular dynamics (MD) simulations methods (i.e., Molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) approaches).

Preparation and in vitro evaluation of 5-flourouracil loaded magnetite-zeolite nanocomposite (5-FU-MZNC) for cancer drug delivery applications.

In this work, super paramagnetic magnetite nanoparticles were synthesized onto/into zeolite, then loaded with anti-cancer drug 5-fluorouracil (5-FU). The physical properties of the prepared nanocomposite and drug loaded nanocomposite were characterized using different techniques. The drug loading and releasing behavior of the magnetic nanocarrier was investigated and the drug-loaded nanoparticles exhibited a sustained release of drug without any burst release phenomenon. Furthermore, 5-FU loaded MZNC were evaluated for its biological characteristics. The functional 5-FU-MZNC has been triggered intra-cellular release of the cancer therapeutic agent 5-fluorouracil (5-FU). Cytotoxic effects of 5-FU loaded MZNC on human gastric carcinoma (AGS) cells were determined by real time cell analysis and colorimetric WST-1 cell viability assay. Apoptosis of cells was further investigated by Annexin-V staining which indicates the loss of cell membrane integrity. According to our results, 5-FU-MZNC showed a concentration-dependent cell proliferation inhibitory function against AGS cells. Morphologic and apoptotic images were consistent with the cytotoxicity results. In conclusion, 5-FU loaded MZNC efficiently inhibit the proliferation of AGS cells in vitro through apoptotic mechanisms, and may be a beneficial agent against cancer, however further animal study is still required.

Synthesis, antioxidant and carbonic anhydrase I and II inhibitory activities of novel sulphonamide-substituted coumarylthiazole derivatives.

New secondary benzenesulphonamide-substituted coumarylthiazole derivatives were synthesized and their inhibitory effects on purified carbonic anhydrase I and II were evaluated using CO2 as a substrate. The result showed that all the synthesized compounds exhibited inhibitory activity on both hCA I and hCA II with N-(4-(2-oxo-2H-chromen-3-yl)thiazol-2-yl)naphthalene-2-sulphonamide (5f, IC50 value of 5.63 and 8.48 µM, against hCA I and hCA II, respectively) as the strongest inhibitor revealed from this study. Structure-activity relationship revealed that the inhibitory activity of the synthesized compounds is related to the type of the halogen and bulky substituent on the phenyl ring. In addition, the cupric reducing antioxidant capacities (CUPRAC) and ABTS cation radical scavenging abilities of the synthesized compounds were assayed. 4-methoxy-N-(4-(2-oxo-2H-chromen-3-yl)thiazol-2-yl)benzenesulphonamide (5e) exhibited the strongest ABTS and CUPRAC activity with IC50 value of 48.83 µM and A0.50 value of 23.29 µM, respectively.

Potential of aryl-urea-benzofuranylthiazoles hybrids as multitasking agents in Alzheimer's disease.

New benzofuranylthiazole derivatives containing the aryl-urea moiety were synthesized and evaluated in vitro as dual acetylcholinesterase (AChE)-butyrylcholinesterase (BuChE) inhibitors. In addition, the cupric reducing antioxidant capacities (CUPRAC) and ABTS cation radical scavenging abilities of the synthesized compounds were assayed. The result showed that all the synthesized compounds exhibited inhibitory activity on both AChE and BuChE with 1-(4-(5-bromobenzofuran-2-yl)thiazol-2-yl)-3-(2-fluorophenyl)urea (e25, IC50 value of 3.85 µM) and 1-(4-iodophenyl)-3-(4-(5-nitrobenzofuran-2-yl)thiazol-2-yl)urea (e38, IC50 value of 2.03 µM) as the strongest inhibitors against AChE and BuChE, respectively. Compound e38 was 8.5-fold more potent than galanthamine. The selectivity index of e25 and e38 was 2.40 and 0.37 against AChE and BuChE, respectively. Compound e2, e4 and e11 (IC50 = 0.2, 0.5 and 1.13 µM, respectively) showed a better ABTS cation radical scavenging ability than the standard quercetin (IC50 = 1.18 µM). Best poses of compounds e38 on BuChE and e25 on AChE indicate that the thiazole ring and the amidic moiety are important sites of interaction with both ChEs. In addition, the benzofuran ring and phenyl ring are anchored to the side chains of both enzymes by π-π(pi-pi) interactions.

Synthesis, antioxidant and anticholinesterase activities of novel coumarylthiazole derivatives.

A newly series of coumarylthiazole derivatives containing aryl urea/thiourea groups were synthesized and their inhibitory effects on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were evaluated. The result showed that all the synthesized compounds exhibited inhibitory activity to both cholinesterases. Among them, 1-(4-(8-methoxy-2-oxo-2H-chromen-3-yl)thiazol-2-yl)-3-(4-chlorophenyl)thiourea (f8, IC50 = 4.58 µM) was found to be the most active compound against AChE, and 1-(4-fluorophenyl)-3-(4-(6-nitro-2-oxo-2H-chromen-3-yl)thiazol-2-yl)urea (e31) exhibited the strongest inhibition against BuChE with IC50 value of 4.93 µM, which was 3.5-fold more potent than that of galantamine. The selectivity of f8 and e31 were 2.64 and 0.04, respectively. In addition, the cupric reducing antioxidant capacities (CUPRAC) and ABTS cation radical scavenging abilities of the synthesized compounds were investigated for antioxidant activity. Among them, f8, f4 and f6 (IC50=1.64, 1.82 and 2.69 µM, respectively) showed significantly better ABTS cation radical scavenging ability than standard quercetin (IC50 = 15.49 µM).