Synthesis and molecular docking studies of 5-trifluoromethoxy-2-indolinones as cholinesterase dual inhibitors.

Background: In Alzheimer's disease, butyrylcholinesterase (BuChE) activity gradually increases, while acetylcholinesterase (AChE) activity decreases or remains unchanged. Dual inhibitors have important roles in regulation of synaptic acetylcholine levels and progression of Alzheimer's disease. Methods: 1-(Thiomorpholin-4-ylmethyl)/benzyl-5-trifluoromethoxy-2-indolinones (6-7) were synthesized. AChE and BuChE inhibitory effects were investigated with Ellman's method. Molecular docking studies were performed for analyzing the possible binding interactions at active sites. Results: Compound 6g was the strongest inhibitor against both AChE (Ki = 0.35 µM) and BuChE (Ki = 0.53 µM). It showed higher inhibitory effects than both donepezil and galantamine. Moreover, compound 7m had a higher inhibitory effect than galantamine and the effect was comparable to that of donepezil against both AChE (Ki = 0.69 µM) and BuChE (Ki = 0.95 µM). Conclusion: The benzyl substitution compared with 1-(thiomorpholin-4-ylmethyl) group significantly increased both AChE and BuChE inhibitory effects.

Synthesis and molecular modeling studies of 1-benzyl-2-indolinones as selective AChE inhibitors.

Background: Possible bioisosteres can be developed by replacing the 1-indanone ring (one of three pharmacophore groups) of donepezil with an indoline ring. As H2S donors, thioamide, thiocarbamate and thiourea groups are also critically important. Materials & methods: The 1-benzyl-2-indolinones 6a-n were designed using molecular modeling and synthesized, and their acetylcholinesterase and butyrylcholinesterase inhibitory effects were then investigated. Results: The compounds 6h (inhibition constant [Ki] = 0.22 µM; selectivity index [SI] = 26.22), 6i (Ki = 0.24 µM; SI = 25.83), 6k (Ki = 0.22 µM; SI = 28.31) and 6n (Ki = 0.21 µM; SI = 27.14) were approximately twofold more effective against and >12-fold more selective for acetylcholinesterase compared with donepezil (Ki = 0.41 µM; SI = 2.12). Analysis of molecular dynamics simulations with compounds 6k and 6n indicated that the preferred binding might be at allosteric binding pocket 4 of the enzyme. Conclusion: Benzyl substitution at the 1-position of the indole ring significantly increased potency and selectivity.

Synthesis, molecular modeling and cholinesterase inhibitory effects of 2-indolinone-based hydrazinecarbothioamides.

Background: 2-Indolinone-based hydrazinecarbothioamides carrying a 3-phenylsulfonamide moiety (7-9) were designed by replacement of donepezil's pharmacophore group indanone with a 2-indolinone ring. Method: Compounds 7-9 were synthesized by reaction of N-(3-sulfamoylphenyl)hydrazinecarbothioamide (6) with 1H-indolin-2,3-diones (1-3). Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory effects of compounds 7-9 were assayed. Molecular modeling studies of 5-chloro-1,7-dimethyl-substituted compound 8e were carried out to determine the possible binding interactions at the active site of AChE. Results: Compound 8e showed the strongest inhibition against AChE (Ki = 0.52 ± 0.11 µM) as well as the highest selectivity (SI = 37.69). The selectivity for AChE over BuChE of compound 8e was approximately 17-times higher than donepezil and 26-times higher than galantamine. Conclusion: Further development of compounds 7-9 may present new promising agents for Alzheimer's treatment.

Two new phenolic compounds and some biological activities of Scorzonera pygmaea Sibth. & Sm. subaerial parts.

Phytochemical composition of ethyl acetate fraction and total phenolic content, in vitro antioxidant, anti-inflammatory, antimicrobial activities of petroleum ether, chloroform, ethyl acetate and n-butanol fractions of the ethanol extract obtained from the subaerial parts of Scorzonera pygmaea Sibth. & Sm. (Asteraceae) were investigated. Nine compounds; scorzopygmaecoside (1), scorzonerol (2), cudrabibenzyl A (3), thunberginol C (4), scorzocreticoside I (5) and II (6), chlorogenic acid (7), chlorogenic acid methyl ester (8), 3,5-di-O-caffeoylquinic acid (9) were isolated and identified using spectroscopic methods. All substances were isolated for the first time from this species. Compounds 1 and 2 are new. The fractions showed high antioxidant capacity correlated with their phenolic content and no significant antimicrobial activity against tested bacteria and fungi. COX inhibition test was used to evaluate the anti-inflammatory activity and all the fractions showed low inhibition in comparison with indomethacin.

Evaluation of Chemical Composition and In-vitro Biological Activities of Three Endemic Hypericum Species from Anatolia (H. thymbrifolium, H. spectabile and H. pseudolaeve).

In the present work we carried out a phytochemical and biological investigation on three endemic Hypericum species, i.e.Hypericum thymbrifolium (H. thymbrifolium), Hypericum spectabile (H. spectabile) and Hypericum pseudolaeve (H. pseudolaeve) from Anatolia in order to discover new sources of natural compounds for the treatment of inflammatory and neurodegenerative disorders. HPLC-DAD analysis indicated that two naphthodianthrones (pseudohypericin and hypericin) together with chlorogenic acid, rutin, hyperoside, isoquercitrin, kaempferol, quercitrin, quercetin, amentoflavone, and hyperforin are the main compounds present in the methanol extracts. After chemical characterization, all extracts were in-vitro biologically assayed for antioxidant potential by lipid peroxidation inhibitory activity, DPPH, FRAP assays, and superoxide radical scavenging activity, for AChE inhibitory activity by Ellman's method, for COX inhibitory activity by using enzyme immunoassay (EIA) kit, for cytotoxic activity on HeLa and NRK-52E cell lines by MTT assay. The superoxide radical scavenging activity and lipid peroxidation inhibitory activity of H. spectabile (EC50 = 0.430 mg/mL) were more remarkable than that of H. thymbrifolium and H. pseudolaeve. The extracts showed moderate inhibitory activity on AChE (from 49.37% to 63.41%). The best inhibitory activity against COX-1 (71.77% and 77.04%, respectively) and COX-2 ( 64.14% and 72.23%, respectively) were shown by H. thymbrifolium and H. spectabile, which may be due to their richest chlorogenic acid content (0.29576% and 0.23567%, respectively). Cytotoxicity screening results showed that the extracts did not demonstrate significant cytotoxic activity. It was concluded that the most promising extract with antioxidant, anti-inflammatory, and AChE inhibition potential is H. spectabile.

Antioxidant, Anti-acetylcholinesterase, Anti-inflammatory and DNA Protection Activities of Glaucium grandiflorum var. grandiflorum.

In this study, antioxidant, antiacetylcholinesterase, anti-inflammatory, and DNA protecting activities of the aerial parts of Glaucium grandiflorum var. grandiflorum were evaluated. The lyophilized methanolic extract of the aerial parts of G. grandiflorum var. grandiflorum was investigated for potential in-vitro antioxidant properties in thiobarbituric acid test using the lipid peroxidation of liposomes, ferric ion reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl,2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonate) free-radicals and hypochlorous acid scavenging assays. The extract demonstrated antioxidant activity in all the assays. The (AChE) inhibition capacity of the lyophilized methanolic extract at 320 µg/mL (80.75 ± 1.59%) was found to be strong and almost equal to the inhibition capacity of the positive control, galantamine (82.23 ± 2.21%) at 25 µg/mL. The significant AChE inhibitory activity suggests that the extract may be beneficial in the treatment of Alzheimer's disease. The extract also showed inhibitory activity against plasmid DNA damage (94%), as well as COX-2 69.05%, which is a target for many anti-inflammatory and cancer-preventive drugs. These results indicate that G. grandiflorum var. grandiflorum methanolic extract is an excellent source of compounds with antioxidant, anti-acetylcholinesterase and anti-inflammatory properties that prevent DNA damage.

The immune system as a chronotoxicity target of the anticancer mTOR inhibitor everolimus.

The circadian timing system controls many biological functions in mammals including xenobiotic metabolism, detoxification, cell proliferation, apoptosis and immune functions. Everolimus is a mammalian target of rapamycin inhibitor, whose immunosuppressant properties are both desired in transplant patients and unwanted in cancer patients, where it is indicated for its antiproliferative efficacy. Here we sought whether everolimus circadian timing would predictably modify its immunosuppressive effects so as to optimize this drug through timing. C57BL/6J mice were synchronized with light-dark 12h:12h, with L onset at Zeitgeber Time (ZT) 0. Everolimus was administered orally to male (5 mg/kg/day) and female mice (15 mg/kg/day) at ZT1, during early rest span or at ZT13, during early activity span for 4 weeks. Body weight loss, as well as hematological, immunological and biochemical toxicities, were determined. Spleen and thymus were examined histologically. Everolimus toxicity was less severe following dosing at ZT13, as compared to ZT1, as shown with least body weight inhibition in both genders; least reductions in thymus weight both in males (p < 0.01) and females (p < 0.001), least reduction in female spleen weight (p < 0.05), and less severe thymic medullar atrophy both in males (p < 0.001) and females (p < 0.001). The mean circulating counts in total leukocytes, total lymphocytes, T-helper and B lymphocytes displayed minor and non-significant changes following dosing at ZT13, while they were decreased by 56.9% (p < 0.01), 45.5% (p < 0.01), 43.1% (p < 0.05) and 48.7% (p < 0.01) after everolimus at ZT1, respectively, in only male mice. Chronotherapy of everolimus is an effective way to increase the general tolerability and decrease toxicity on the immune system.

New spiroindolinones bearing 5-chlorobenzothiazole moiety.

In this study, 5-chloro-3H-spiro-[1,3-benzothiazole-2,3'-indole]-2'(1'H)-one derivatives 3a-l were synthesized by the reaction of 1H-indole-2,3-diones 1a-l with 2-amino-4-chlorothiophenol 2 in ethanol. 3a-l were tested for their abilities to inhibit lipid peroxidation (LP), scavenge DPPH(•) and ABTS(•+) radicals, and to reduce Fe(3+) to Fe(2+). Most of the tested compounds exhibited potent scavenging activities against ABTS(•+) radical, reducing powers and strong inhibitory capacity on LP. 3 a, 3 d, 3 e, 3h, 3 j and 3 k chosen as prototypes were evaluated in the National Cancer Institute's in vitro primary anticancer assay. The greatest growth inhibitions were observed against a non-small cell lung cancer cell line HOP-92 for R1-fluoro substituted 3 d and a renal cancer cell line RXF-393 for R-chloro substituted 3 e in the primary screen.

Influence of vanadium supplementation on oxidative stress factors in the muscle of STZ-diabetic rats.

In recent years, the role of free radical damage consequent to oxidative stress is widely discussed in diabetic complications. In this aspect, the protection of cell integrity by trace elements is a topic to be investigated. Vanadium is a trace element believed to be important for normal cell function and development. The aim of the present study was to investigate the effect of vanadyl sulfate supplementation on the antioxidant system in the muscle tissue of diabetic rats. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ, 65 mg/kg body weight) to male Swiss albino rats. The rats were randomly divided into 4 groups: Group I, control; Group II, vanadyl sulfate control; Group III, STZ-diabetic untreated; Group IV, STZ-diabetic treated with vanadyl sulfate. Vanadyl sulfate (100 mg/kg) was given daily by gavage for 60 days. At the last day of the experiment, rats were killed, muscle tissues were taken, homogenized in cold saline to make a 10% (w/v) homogenate. Body weights and blood glucose levels were estimated at 0, 30 and 60th days. Antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST), as well as carbonic anhydrase (CA), myeloperoxidase (MPO) activities and protein carbonyl content (PCC) were determined in muscle tissue. Vanadyl sulfate administration improved the loss in body weight due to STZ-induced diabetes and decreased the rise in blood glucose levels. It was shown that vanadium supplementation to diabetic rats significantly decrease serum antioxidant enzyme levels, which were significantly raised by diabetes in muscle tissue showing that this trace element could be used as preventive for diabetic complications.

Flavonoids and antioxidant activity of Rosa agrestis leaves.

In this work we report the isolation and characterisation of seven flavonoids, the levels of total phenolics, flavonoids and proanthocyanidins, and the antioxidant activity of the leaf extract of Rosa agrestis Savi (Rosaceae). The results showed that the R. agrestis leaf extract exhibited significant antioxidative activity as measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) (EC(50) = 47.4 microg mL(-1)), inhibited both beta-carotene bleaching and deoxyribose degradation, quenched a chemically generated superoxide anion in vitro and showed high ferrous ion chelating activity. Reactivity towards 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical cation and ferric-reducing antioxidant power (FRAP) values were equivalent to 2.30 mM L(-1) Trolox, the water soluble alpha-tocopherol analogue, and 1.91 mM L(-1) Fe(2+), respectively. The high antioxidant activity of the extract appeared to be attributed to its high content of total phenolics, flavonoids and proanthocyanidins. The flavonoids isolated from R. agrestis leaves were diosmetin, kaempherol, quercetin, kaempherol 3-glucoside (astragalin), quercetin 3-rhamnoside (quercitrin), quercetin 3-xyloside and quercetin 3-galactoside (hyperoside). Diosmetin (5,7,3'-trihydroxy-4'-methoxyflavone) was isolated for the first time from Rosa species.

Synthesis of new spiroindolinones incorporating a benzothiazole moiety as antioxidant agents.

3H-Spiro[1,3-benzothiazole-2,3'-indol]-2'(1'H)-ones 3a-c and 4a-e were synthesized from treating the 5-substituted 1H-indole-2,3-diones with 2-aminothiophenol in ethanol. The structures were confirmed by elemental analyses, spectrometry (IR, (1)H NMR, (13)C NMR, HSQC-2D and LCMS-APCI) and single crystal X-ray analysis. The new compounds were screened for their antioxidant activities such as the Fe(3+)/ascorbate system induced inhibition of lipid peroxidation (LP) in liposomes, trolox equivalent antioxidant capacity (TEAC), scavenging effect on diphenylpicryl hydrazine (DPPH*), and reducing power. These compounds showed potent scavenging activities against DPPH* and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS*(+)) radicals, reducing powers, and strong inhibitory capacity on lipid peroxidation. Compound 4a incorporating methyl both at R(1) and R(2) was found to be the most potent antioxidant described in this study. Compounds 3b and 4b were selected as representative compounds by the National Cancer Institute for screening against anticancer activity and these compounds were found to be cytotoxic against CNS cancer cell line SNB-75 in the primary screen.

Implications for degenerative disorders: antioxidative activity, total phenols, flavonoids, ascorbic acid, beta-carotene and beta-tocopherol in Aloe vera.

In order to demonstrate whether the known biological effects of Aloe vera (L.) Burm. fil. could correlate with the antioxidant activity of the plant, the antioxidant activity of the aqueous leaf extract was investigated. The present study demonstrated that the aqueous extract from A. vera leaves contained naturally occuring antioxidant components, including total phenols, flavonoids, ascorbic acid, beta-carotene and alpha-tocopherol. The extract exhibited inhibitory capacity against Fe(3+)/ascorbic acid induced phosphatidylcholine liposome oxidation, scavenged stable DPPH(*), ABTS(*+) and superoxide anion radicals, and acted as reductant. In contrast, the leaf inner gel did not show any antioxidant activity. It was concluded that the known beneficial effects of Aloe vera could be attributed to its antioxidant activity and could be related to the presence of phenolic compounds and antioxidant vitamins.

Effect of Aloe vera (L.) Burm. fil. leaf gel and pulp extracts on kidney in type-II diabetic rat models.

Significant degenerative changes were observed in the kidney tissue of untreated neonatal streptozotocin (n0STZ)-induced type-II diabetic rats. These degenerative changes were diminished in the kidney tissue of diabetic animals given glibenclamide and Aloe leaf gel and pulp extracts. Kidney lipid peroxidation levels were increased in diabetic rats compared to healthy rats; these levels were higher in rats treated with glibenclamide than in those which received Aloe extracts. Serum urea and creatinine levels were higher in diabetic rats in comparison to healthy rats. The administration of Aloe gel extract and glibenclamide decreased serum urea and creatinine levels in comparison to diabetic controls. Only A. vera leaf gel extract showed improvement both in histological and biochemical parameters suggesting a protective effect of A. vera on mild damage caused by type-II diabetes on kidney tissue.

Effect of Aloe vera leaf gel and pulp extracts on the liver in type-II diabetic rat models.

The aim of this work was to investigate the effects of Aloe vera leaf pulp and gel extracts on the liver tissue of neonatal streptozotocin (n0STZ)-induced type-II diabetic rats. The diabetic rats were separated into four groups and each group was given the following samples by gavage, daily for 15 d: phosphate buffered saline (PBS; diabetic control), Aloe leaf pulp extract, Aloe leaf gel extract, glibenclamide. Liver tissues were examined histologically. The markers of oxidative stress: glutathione (GSH), non-enzymatic glycosylation (NEG) and lipid peroxidation (LPO), were determined in liver tissue. Biochemical parameters for liver function: serum alkaline phosphatase (ALP), and alanine transaminase (ALP) activities, were evaluated. All parameters were also determined in healthy (non diabetic) rats for comparison. In the diabetic control group, the degenerative changes in liver tissue were remarkable, while in the diabetic groups given Aloe pulp and gel extracts and glibenclamide, the damage to the liver tissue was decreased. The increase of GSH and the decrease of NEG and LPO in liver tissues with the treatment of Aloe gel extract, is consistent with the beneficial effect of Aloe. Serum ALP and ALT activities were also decreased in the groups given Aloe gel extract. It was concluded that Aloe gel extract has a protective effect comparable to glibenclamide against hepatotoxicity produced by diabetes if used in the treatment of type-II diabetes.

Production and characterization of alpha-galactosidase from Aspergillus flavipes.

An extracellular alpha-galactosidase from the culture filtrate of Aspergillus flavipes grown on melibiose as a carbon source was partially purified by hydroxylapatite and diethylaminoethylcellulose chromatographies. Electrophoretic analysis showed protein bands corresponding to alpha-galactosidase and invertase activities. The optimum pH and temperature were determined as 4.5-5.0 and 45 degrees C, respectively. The Km value for p-nitrophenyl-alpha-d-galactopyranoside was found to be 1.89 mm. The results reported in this study indicate that Aspergillus flavipes is indeed an active source of extracellular alpha-galactosidase.