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Showing papers in "Archiv Der Pharmazie in 2012"


Journal ArticleDOI
TL;DR: The results showed that the synthesized bromophenols had effective antioxidant power and the phenol 5 with two phenolic rings and five phenolic hydroxyl groups was the most potent antioxidant and radical scavenger.
Abstract: (3,4-Dihydroxyphenyl)(2,3,4-trihydroxyphenyl)methanone (5) and its two derivatives with bromine were synthesized from reactions such as bromination and demethylation of (3,4-dimethoxyphenyl)(2,3,4-trimethoxyphenyl)methanone (6). The Wolf-Kishner reduction product (9) of 6 and its three derivatives with bromine were obtained. 4-(3,4-Dihydroxybenzyl)benzene-1,2,3-triol and its dibromide derivative (16) were also synthesized from 9 and the corresponding dibromide derivative. The in vitro antioxidant activities of nine new compounds synthesized in these reactions were determined by analyzing the radical scavenging activities of bromophenols for 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picryl-hydrazyl (DPPH), N,N-dimethyl-p-phenylenediamine (DMPD), and the superoxide anion radical (O(2)(·-)) and examining the total reducing power through Fe(3+)-Fe(2+) transformation, FRAP and CUPRAC assays and the ferrous ions (Fe(2+)) chelating activities. Moreover, the results of these activities were compared to those of standard antioxidant compounds such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol, and trolox. The results showed that the synthesized bromophenols had effective antioxidant power. The phenol 5 with two phenolic rings and five phenolic hydroxyl groups was the most potent antioxidant and radical scavenger. In conclusion, the new compounds are promising molecules to be used owing to their potential antioxidant properties.

89 citations


Journal ArticleDOI
TL;DR: Development of small molecules as epigenetic tools that alter histone acetyltransferase activity will be helpful to better understand the consequences of histone and generally protein acetylation and potentially offer novel therapeutic approaches for the treatment of cancer and other diseases.
Abstract: Alteration of the acetylation state of histone proteins contributes to transcriptional regulation and epigenetic inheritance. Dysregulation of these processes may lead to human diseases, especially cancer. One of the major chromatin modifications is histone acetylation and this review gives an overview of the role of histone acetyltransferases, their structural aspects, as well as of chemical modulators targeting their enzymatical activities. Inhibitors and activators of histone acetyltransferases are presented and their capability to influence histone and non-histone protein acetylation levels is discussed. Development of small molecules as epigenetic tools that alter histone acetyltransferase activity will be helpful to better understand the consequences of histone and generally protein acetylation and potentially offer novel therapeutic approaches for the treatment of cancer and other diseases.

78 citations


Journal ArticleDOI
TL;DR: Newly synthesized compounds were screened for their antioxidant activity, erythrocytes haemolysis and bleomycin‐independent DNA damage and some of the tested compounds exhibited promising activities.
Abstract: 2-Tosylacetonitrile (1) when reacted with α,β-unsaturated nitriles 2a-c or a mixture of formaldehyde and 3-amino-2-substituted-pent-2-endinitriles 6a,b yielded pyridine derivatives 3a-c and 9a,b, respectively, while when subjected to react with salicylaldehyde yielded chromene derivatives 4 and 5, subsequently. The behavior of thiocarbamoyl derivative 10 derived from 1 towards some α-halogenated compounds have been investigated as well as its behavior towards elemental sulfur and phenyl isothiocyanate. Newly synthesized compounds were screened for their antioxidant activity, erythrocytes haemolysis and bleomycin-independent DNA damage. Some of the tested compounds exhibited promising activities.

63 citations


Journal ArticleDOI
TL;DR: Generally, among the tested compounds, those containing a free carboxylic acid functional group on the pyrazole ring were the most active and this finding was supported by the docking results performed for the active compounds.
Abstract: Novel series of pyrazole derivatives were synthesized and tested for their in vivo anti-malarial activity using mice infected with chloroquine sensitive P. berghei at a dose level of 50 µmol/kg. The most active compounds were further tested in vitro against chloroquine resistant (RKL9) strain of P. falciparum. The in vivo anti-malarial activity study indicated that compounds 2a, 2b, 8a and 8b had mean percent suppression of 85%, 83%, 95% and 97%, respectively at equimolar dose level of the standard drug chloroquine diphosphate. Moreover, compounds 2a, 2b, 8a and 8b showed in vitro IC(50) values lower (p < 0.05) than that of the standard drug chloroquine phosphate (0.188 ± 0.003 µM) using the RKL9 strain. Compound 8b was the most active with IC(50) of 0.033 ± 0.014 µM. Generally, among the tested compounds, those containing a free carboxylic acid functional group on the pyrazole ring were the most active and this finding was supported by the docking results performed for the active compounds. The acute toxicity studies of the active compounds revealed that they have a good safety profile.

56 citations


Journal ArticleDOI
TL;DR: The majority of the compounds synthesized were found to be active against Bacillus subtilis, Clostridium tetani and Candida albicans as compared to standard drugs.
Abstract: A new series of pyrano[4,3-b]pyran 4a-i and pyrano[3,2-c]chromene 6a-r derivatives bearing a 2-thiophenoxyquinoline nucleus were synthesized by reaction of 2-(4-(un)-substituted thiophenoxy)quinoline-3-carbaldehydes 2a-i with 6-methyl-4-hydroxypyran-2-one 3 and 4-hydroxy-6-(un)-substituted-2H-chromen-2-one 5a-b respectively and malononitrile at room temperature in the presence of KOH as a basic catalyst. All the compounds were screened against three Gram-positive bacteria (Streptococcus pneumoniae, Bacillus subtilis, Clostridium tetani), three Gram-negative bacteria (Salmonella typhi, Escherichia coli, Vibrio cholerae) and two fungi (Candida albicans, Aspergillus fumigatus) using the broth microdilution MIC (minimum inhibitory concentration) method. Upon antimicrobial screening, it was observed that the majority of the compounds were found to be active against Bacillus subtilis, Clostridium tetani and Candida albicans as compared to standard drugs.

54 citations


Journal ArticleDOI
TL;DR: Many derivatives of heterocyclic compounds containing a sulfonamide thiazole moiety were synthesized through the reaction of 2‐(cyano or chloro)‐N‐(4‐(N‐thiazol‐2‐ylsulfamoyl)phenyl)acetamide with isocyanate and 6 compounds showed protection against picrotoxin‐induced convulsion.
Abstract: Many derivatives of heterocyclic compounds containing a sulfonamide thiazole moiety were synthesized through the reaction of 2-(cyano or chloro)-N-(4-(N-thiazol-2-ylsulfamoyl)phenyl)acetamide with isocyanate followed by halogenated compounds, arylidene, 2-hydroxy benzaldehydes, active methylene compounds, and heterocyclic amines. The anticonvulsant activity for 15 of the synthesized compounds was evaluated and 6 compounds showed protection against picrotoxin-induced convulsion. 4-(6-Amino-3,5-dicyano-4-(4-methoxyphenyl)-2-oxopyridin-1(2H)-yl)-N-(thiazol-2-yl)benzenesulfonamide (11b) exhibited significant anticonvulsive effects, abolished the tonic extensor phase and offered 100% protection.

53 citations


Journal ArticleDOI
TL;DR: The most promising selective AChE inhibitors are compounds 10 and 11, with 6–7 methylene chains, which also inhibit Aβ fibril formation, which support the outcome of docking studies which tested compounds targeting both the catalytic active site (CAS) and the peripheral anionic site (PAS) of A ChE.
Abstract: A new series of 2-(diethylaminoalkyl)-isoindoline-1,3-dione derivatives intended as dual binding site cholinesterase inhibitors were designed using molecular modeling and evaluated as inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and the formation of the β-amyloid (Aβ) plaques. For AChE inhibitory activity, the spectrophotometric method of Ellman and the electrophoretically mediated microanalysis assay were used, giving good results. Most of the synthesized compounds had AChE inhibitory activity with IC(50) values ranging from IC(50) = 0.9 to 19.5 µM and weak Aβ anti-aggregation inhibitory activity. These results support the outcome of docking studies which tested compounds targeting both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. The most promising selective AChE inhibitors are compounds 10 (IC(50) = 1.2 µM) and 11 (IC(50) = 1.1 µM), with 6-7 methylene chains, which also inhibit Aβ fibril formation.

48 citations


Journal ArticleDOI
TL;DR: Among the synthesized compounds, the 5‐(3‐methylphenyl)isoxazol‐3‐yl analog (7j) showed the most potent cytotoxic activity against all five human tumor cell lines.
Abstract: A new series of 4-aryl-4H-chromenes bearing a 5-arylisoxazol-3-yl moiety at the C-4 position were prepared as potential anticancer agents. The in vitro cytotoxic activity of the synthesized compounds was investigated against a panel of tumor cell lines including MCF-7 (breast cancer), KB (nasopharyngeal epidermoid carcinoma), Hep-G2 (liver carcinoma), MDA-MB-231 (breast cancer), and SKNMC (human neuroblastoma) using the MTT colorimetric assay. Doxorubicin, a well-known anticancer drug, was used as positive standard drug. Among the synthesized compounds, the 5-(3-methylphenyl)isoxazol-3-yl analog (7j) showed the most potent cytotoxic activity against all five human tumor cell lines.

43 citations


Journal ArticleDOI
TL;DR: The analgesic and antiinflammatory activities of the newly synthesized compounds were investigated and showed significant activities and the antitumor activity of five new phosphonates against four carcinoma cell lines was estimated.
Abstract: Carbodiimide that was generated from the condensation reaction of iminophosphorane with phenylisocyanate was allowed to react with different phosphorus nucleophiles. Thus, the in situ resulted heterocumulene reacted with dialkylhydrogenphosphonates in tetrahydrofuran (THF)/FeCl(3) /H(2) O system to give fused pyrrole- (≈14%) and pyrimidinephosphonates (≈57%). On the other hand, with tris-(dialkyl)aminophosphines, the reaction afforded the corresponding hexaalkylphosphinic diamides as a water-sensitive fine powder, quite stable for a few days in a desiccator. When a protonating agent was present in the reaction medium, the reaction was markedly accelerated leading to the formation of the phosphamides. Next, some saturated and unsaturated Horner-Emmons reagents were applied in situ to the same carbodiimide to obtain more phosphorylated N-heterocycles. The analgesic and antiinflammatory activities of the newly synthesized compounds were investigated and showed significant activities. Finally, we further estimated the antitumor activity of five new phosphonates against four carcinoma cell lines.

43 citations


Journal ArticleDOI
TL;DR: A new series of benzo[6,7]cyclohepta[1,2‐d]triazolo[4,3‐a]pyrimidines 8a–l was synthesized via reaction of heterocyclic thione 4 or its methyl derivatives 10 with hydrazonoyl halides 5a-l and showed activities with good ED50 for all compounds.
Abstract: A new series of benzo[6,7]cyclohepta[1,2-d]triazolo[4,3-a]pyrimidines 8a-l was synthesized via reaction of heterocyclic thione 4 or its methyl derivatives 10 with hydrazonoyl halides 5a-l. Also, reaction of compound 4 with a mixture of chloroacetic acid and aromatic aldehyde derivatives gave benzo[6,7]cyclohepta[1,2-d]thiazolo[3,2-a]pyrimidin-3-ones 12-14. The microanalyses and spectral data of the synthesized compounds are in full agreement with their molecular structure. All the newly synthesized products were screened against 5α-reductase and showed activities with good ED(50) for all compounds.

42 citations


Journal ArticleDOI
TL;DR: The bioevaluation demonstrated that most compounds in the series of 4a–4x exhibited potent anticonvulsant activity in the maximal electroshock test, and 6‐(4‐chlorophenyl)‐[1,2,4]triazolo[3,4‐b]thiadiazole (4h) emerged as the most promising candidate on the basis of its favorable ED50 value and PI value.
Abstract: The present study describes the synthesis and anticonvulsant activity evaluation of 6-substituted-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives (4a-4x) and their partially dehydrogenated products 5,6-dihydro-6-substituted-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives (5a-5n). The bioevaluation demonstrated that most compounds in the series of 4a-4x exhibited potent anticonvulsant activity in the maximal electroshock test. Among which, 6-(4-chlorophenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole (4h) emerged as the most promising candidate on the basis of its favorable ED(50) value of 23.7 mg/kg and PI value of 10.8. In addition, the potency of compound 4h against seizures induced by pentylenetetrazole, 3-mercaptopropionic acid, and bicuculline in the chemical-induced seizure tests suggested that compound 4h displayed broad-spectrum activity in several models, and it may exert its anticonvulsant activity through affecting the GABAergic system.

Journal ArticleDOI
TL;DR: A novel series of indolin‐2‐one derivatives containing the 4‐thiazolidinone moiety (5a—5p) was synthesized and the cytotoxicity of these derivatives was evaluated in vitro against three human cancer cell lines by standard MTT assay.
Abstract: A novel series of indolin-2-one derivatives containing the 4-thiazolidinone moiety (5a-5p) was synthesized and the cytotoxicity of these derivatives was evaluated in vitro against three human cancer cell lines (HT-29, H460 and MDA-MB-231) by standard MTT assay. Some prepared compounds exhibited significant cytotoxicity against different human cancer cell lines. Several potent compounds were further evaluated against one normal cell line (WI-38). In particular, the promising compound 5h showed remarkable cytotoxicity and selectivity against the HT-29 and H460 cancer cell lines (IC(50) = 0.016 µmol/L, 0.0037 µmol/L, respectively).

Journal ArticleDOI
TL;DR: The conformational arrangement of the side chain, electronic features, and the hydrophilic/hydrophobic balance seem to be relevant for explaining the antileishmanial activity of dillapiole and its analogues.
Abstract: In this paper, the isolation of dillapiole (1)fromPiperaduncumwas reported as well as the semi-synthesisof two phenylpropanoid derivatives [di-hydrodillapiole (2), isodillapiole (3)], via reduction andisomerization reactions. Also, the compounds’ molecular properties (structural, electronic,hydrophobic, and steric) were calculated and investigated to establish some preliminary structure–activity relationships (SAR). Compounds were evaluated for in vitro antileishmanial activity andcytotoxic effects on fibroblast cells. Compound 1 presented inhibitory activity against Leishmaniaamazonensis (IC

Journal ArticleDOI
TL;DR: Interestingly, the compounds 3d and 3k did not show any sign of motor impairment at the maximum dose administered and were not toxic to the liver, and were also found to have encouraging anticonvulsant activity.
Abstract: Various 1-[6-(4-substituted phenyl)-3-cyano-4-(substituted phenyl)-pyridin-2-yl]-5-oxopyrrolidine-3-carboxylic acids (3a-t) were designed and synthesized by clubbing pyrrolidinones and pyridines, the two active anticonvulsant pharmacophores. All the synthesized compounds fulfilled the requirements of suggested pharmacophoric model for anticonvulsant activity. Their in vivo anticonvulsant evaluation was performed by maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) tests. The minimal motor impairment was assessed by rotorod test and the estimation of various liver enzymes was performed to check the magnitude of liver toxicity posed by the synthesized compounds. Compounds 3d and 3k displayed comparable anticonvulsant activity to the standard drugs with ED(50) values of 13.4 and 18.6 mg/kg in electroshock screen, repectively. The compounds 3d and 3k were also found to have encouraging anticonvulsant activity (ED(50) = 86.1 and 271.6 mg/kg, respectively) in scPTZ screen. Interestingly, they did not show any sign of motor impairment at the maximum dose administered and were not toxic to the liver.

Journal ArticleDOI
TL;DR: Surprisingly, 6a–6c emerged as the compounds exhibiting the highest antimicrobial activity by possessing a remarkable antibacterial effect against the Gram‐positive strains and the fungi panel with MIC values between 2 and 8 µg/mL.
Abstract: As part of our studies focused on the design and synthesis of new antimicrobial agents a series of 7fluoro-3,4-dihydro-2H-1,4-benzothiazine derivatives (4a–4f, 4h) and 7-fluoro-2H-1,4-benzothiazin-3(4H)one analogues (4j–4o) were synthesized and evaluated for their in vitro inhibitory activity against a representative panel of Gram-positive and Gram-negative bacteria strains and also toward selected fungi species. These compounds were prepared in one step from chloro-substituted-2-amino-5fluorobenzenethiol 6a–6c. The biological screening identified in compounds 4a, 4j and 4l the most promising results of both series showing an interesting antimicrobial activity. Our antibiotic investigation was also completed by testing the key intermediates 6a–6c. Surprisingly, 6a–6c emerged as the compounds exhibiting the highest antimicrobial activity by possessing a remarkable antibacterial effect against the Gram-positive strains with MIC (minimal inhibitory concentration) values between 2 and 8 mg/mL and the fungi panel with MIC values between 2 and 8 mg/mL. These results may prove useful in the design of a novel pool of antimicrobial agents.

Journal ArticleDOI
TL;DR: A series of 3‐nitrochromenes were designed and synthesized and showed good inhibitory activity against thioredoxin reductase (TrxR) and the proliferation of A549 cancer cells.
Abstract: A series of 3-nitrochromenes were designed and synthesized. These compounds showed good inhibitory activity against thioredoxin reductase (TrxR) and the proliferation of A549 cancer cells. The structure-activity relationship analysis indicates that the 3-nitrochromene scaffold is the crucial pharmacophore for achieving good inhibitory activity. The bromo-substitutions at the 6- and 8-position of 3-nitrochromene significantly increase the inhibitory activity.

Journal ArticleDOI
TL;DR: Based on the prediction results (PASS program), anti‐inflammatory activity of the new acids was also determined in vivo, by the acute carrageenin induced paw edema in rats, and many of these compounds showed anti-inflammatory properties at a dose of 50 mg/kg body weight.
Abstract: Methylenebisphosponic acid tetraethyl ester (1) was added to 2-azido-7a-e and 2-chloroquinoline-3-chalcones 10a-e in boiling sodium ethanolate solution to give, via Michael addition, tetrazolo[1,5-a]quinoline-8a-d, 13a and 2-chloroquinoline-based bisphosphonates 11a-d, 14a in E-configuration. Further acid hydrolysis afforded the respective BP-acid analogues E-9a-d, 12a-d, 13b, and 14b in excellent yields. Anti-tumor activity screening for the new BP-acids at a dose of 10 µM utilizing 44 different human tumor cell lines representing breast, ovary, prostate, lung, and CNS cancer as well as leukemia and melanoma was carried out. Eight of ten tested compounds exhibited remarkable anti-tumor activity against breast and prostate cancer, and a promising anti-tumor sensitivity toward ovarian cancer and melanoma. Conversely, there was only scattered activity against leukemia and no noticeable action of these BP-acids on CNS or lung cancer. Based on the prediction results (PASS program), anti-inflammatory activity of the new acids was also determined in vivo, by the acute carrageenin induced paw edema in rats. Many of these compounds showed anti-inflammatory properties at a dose of 50 mg/kg body weight.

Journal ArticleDOI
TL;DR: In an attempt to develop potent anti‐HIV drugs, 20 andrographolide derivatives were designed, synthesized, and evaluated for their in vitro anti-HIV activity, and the screening results revealed that five compounds showed potent anti­HIV activities with therapeutic indices above 10.07.
Abstract: In an attempt to develop potent anti-HIV drugs, 20 andrographolide derivatives were designed, synthesized, and evaluated for their in vitro anti-HIV activity. The screening results revealed that five compounds showed potent anti-HIV activities with therapeutic indices (TI) above 10. The most promising compound 6f shows a significant TI close to 34.07, with the potency to be a new lead.

Journal ArticleDOI
TL;DR: Diethyl anthracen‐9‐yl (hydroxy) methylphosphonate (3n) is the most potent and biologically active compound against free radicals.
Abstract: A series of α-hydroxyphosphonates were synthesized from the reaction of aldehyde (1) with triethylphosphite (2) in the presence of oxone and evaluated for their antioxidant properties against lipid peroxidation, reduced glutathione, superoxide dismutase, and catalase. The majority of the compounds showed promising antioxidant activity. Diethyl anthracen-9-yl (hydroxy) methylphosphonate (3n) is the most potent and biologically active compound against free radicals.

Journal ArticleDOI
TL;DR: Among the tested compounds, 2‐[(2‐(4‐chlorophenyl)‐1H‐benzo[d]imidazole‐1‐yl)methyl]‐5‐ (4‐fluorophenyl]‐1,3,4‐oxadiazole (9) was found to be the most active compound in all three in vitro systems.
Abstract: In this study, two new series of 2-amino-1,3,4-oxadiazoles and 5-aryl-1,3,4-oxadiazoles carrying a benzimidazole moiety were synthesized. The antioxidant properties of these compounds were investigated in vitro by the determination of the microsomal NADPH-dependent inhibition of lipid peroxidation levels (LP), the microsomal ethoxyresorufin O-deethylase activity (EROD), and DPPH radical scavenger effects. Among the tested compounds, 2-[(2-(4-chlorophenyl)-1H-benzo[d]imidazole-1-yl)methyl]-5-(4-fluorophenyl)-1,3,4-oxadiazole (9) was found to be the most active compound in all three in vitro systems.

Journal ArticleDOI
TL;DR: A series of 6‐hydrazinyl‐2,4‐bismorpholino pyrimidine and 1,3,5‐triazine derivatives (5a–5l and 8a–8o) were synthesized and their chemical structures as well as the relative stereochemistry were confirmed.
Abstract: A series of 6-hydrazinyl-2,4-bismorpholino pyrimidine and 1,3,5-triazine derivatives (5a-5l and 8a-8o) were synthesized and their chemical structures as well as the relative stereochemistry were confirmed. All the synthesized compounds were evaluated for antiproliferative activity against three cancer cell lines (H460, HT-29, and MDA-MB-231). Several potent compounds were further evaluated against two other cell lines (U87MG, H1975). Most of the prepared compounds, particularly compounds 5c and 5j with IC(50) values (0.07 and 0.05 µM, respectively) in the nM range, exhibited moderate to excellent antiproliferative activity and high selectivity against the H460 cancer cell line as compared with compound 1. The most promising compound 5j, possessing a cyano group at the 3-position of the benzene ring, showed strong antiproliferative activity against H460, HT-29, and MDA-MB-231 cell lines with IC(50) values of 0.05, 6.31, and 6.50 µM, which were 4.6- to 190.4-fold more active than compound 1 (9.52, 29.24, and 36.21 µM), respectively.

Journal ArticleDOI
TL;DR: A series of derivatives were designed, synthesized, and evaluated in vitro to improve the PTP1B inhibitory activity and indicated that the tricyclic scaffold and multi‐bromine atoms attached to the aryl rings are important for PTP 1B inhibition.
Abstract: 3-Bromo-4,5-bis(2,3-dibromo-4,5-dihydroxybenzyl)-1,2-benzenediol (BDB) is a bromophenol purified from the marine red alga Rhodomela confervoides and exhibits potent protein tyrosine phosphatase 1B (PTP1B) inhibition (IC50?=?1.7?mu mol/L). In an effort to improve the PTP1B inhibitory activity, a series of derivatives were designed, synthesized, and evaluated in vitro. The preliminary structureactivity relationship indicated that the tricyclic scaffold and multi-bromine atoms (four to five) attached to the aryl rings are important for PTP1B inhibition. Among these, compound 26 exhibited remarkable inhibitory activity against PTP1B with an IC50 of 0.89 mu mol/L, which was approximately two-fold more potent than the initial lead compound BDB.

Journal ArticleDOI
TL;DR: The motivation for this present review was the known widespread application of the 1,4‐benzothiazine scaffolds.
Abstract: 1,4-Benzothiazines are known to represent a class of medicinally important heterocyclic compounds which are extensively used in drug design. They have wide biological properties which qualify them as excellent scaffolds in therapeutic and medicinal research. Thus, many derivatives of this compound have been synthesized as target structures in novel drug development. Hence, the motivation for this present review was the known widespread application of the 1,4-benzothiazine scaffolds.

Journal ArticleDOI
TL;DR: Arglabin derivatives varied at the endo‐ or exo‐cyclic double bond were synthesized and studied in a colorimetric sulforhodamine B assay for their cytotoxicity and are an excellent starting material for the synthesis of the guaianolide arborescin.
Abstract: Arglabin derivatives varied at the endo- or exo-cyclic double bond were synthesized and studied in a colorimetric sulforhodamine B assay for their cytotoxicity. Variations on the endocyclic double bond led to compounds of reduced cytotoxicity whereas derivatives from the reaction of the α-methylene-γ-butyrolactone moiety led to compounds of similar or only slightly reduced cytotoxicity but different, cell line-dependent selectivity. In addition, arglabin is an excellent starting material for the synthesis of the guaianolide arborescin.

Journal ArticleDOI
TL;DR: Molecular modeling studies revealed interactions with key amino acid residues in the homology model of histamine H3 receptor ligands, as well as the binding model for AChE and BuChE in the catalytic and peripheral active sites, which displayed high affinity for the cloned hH3R and moderate inhibitory potency against both enzymes.
Abstract: The study presents novel biological properties of diether derivatives of homo- or substituted piperidine ligands of the histamine H(3) receptor. The compounds were evaluated for their inhibitory potency against acetylcholinesterase (AChE) from the electric eel and butyrylcholinesterase (BuChE) from horse serum. The most interesting multifunctional compound 13 displayed high affinity for the cloned hH(3) R (K(i) = 3.48 nM) and moderate inhibitory potency against both enzymes (IC(50) AChE = 7.91 µM and BuChE = 4.97 µM). Molecular modeling studies revealed interactions with key amino acid residues in the homology model of histamine H(3) receptor ligands, as well as the binding model for AChE and BuChE in the catalytic and peripheral active sites.

Journal ArticleDOI
TL;DR: 3‐methyl‐4‐phenyl‐2(3H)‐thiazole thione (4a) showed good tyrosinase inhibitory activity, even better than that of the well‐known tyros inase inhibitor, namely, kojic acid.
Abstract: A series of 2(3H)-thiazole thiones 3-5 was synthesized and evaluated for tyrosinase inhibition and DPPH radical scavenging activities. Among them, 3-methyl-4-phenyl-2(3H)-thiazole thione (4a) showed good tyrosinase inhibitory activity, even better than that of the well-known tyrosinase inhibitor, namely, kojic acid. From the structure-activity point of view, although it was found that the phenolic hydroxyl group in prototype 3-5 might contribute to the scavenging activity against DPPH radicals, there was no correlation between the potency of tyrosinase inhibition and the presence of the phenolic moiety. The in silico ADME-Tox screening revealed that the drug-likeness and drug-score values of the most potent compound 4a were significantly higher than those of kojic acid.

Journal ArticleDOI
TL;DR: The extracts of the roots of licorice have been used in traditional and folk medicine to treat a broad variety of maladies and the main ingredient of these extracts is glycyrrhicinic acid, which has many biological activities, among them a pronounced cytotoxicity against tumor cells.
Abstract: The extracts of the roots of licorice have been used in traditional and folk medicine to treat a broad variety of maladies. The main ingredient of these extracts is glycyrrhicinic acid. Its aglycon, glycyrrhetinic acid, has many biological activities, among them a pronounced cytotoxicity against tumor cells. In this study we varied glycyrrhetinic acid at position C-30 to get "simple" derivatives, for example esters, amides and a nitrile. The influence of these changes on the cytotoxic activity is noteworthy and was determined by a colorimetric sulphorhodamine B test using 7 human tumor cell lines and mouse embryonic fibroblasts (NIH3T3) for comparison. A Trypan blue test as well as an acridine orange/ethidium bromide test was used to discover the ability of the compounds to induce apoptosis.

Journal ArticleDOI
TL;DR: A new series of ethyl 2‐(substituted benzylthio)‐4‐(3′‐(ethoxycarbonyl)‐biphenyl‐ 4‐yl)‐6‐methyl‐1,4‐dihydropyrimidine‐5‐carboxylate derivatives was synthesized and exhibited good antimicrobial activity.
Abstract: In the present study, a new series of ethyl 2-(substituted benzylthio)-4-(3'-(ethoxycarbonyl)-biphenyl-4-yl)-6-methyl-1,4-dihydropyrimidine-5-carboxylate derivatives was synthesized. The newly synthesized compounds were characterized by (1) H-NMR, mass and C, H, N analyses. All newly synthesized compounds were screened for their antibacterial (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pyogenes and Klebsiella pneumoniae) and antifungal (Aspergillus flavus, Aspergillus fumigatus, Candida albicans, Penicillium marneffei and Trichophyton mentagrophytes) activity. The results revealed that all synthesized compounds have a significant biological activity against the tested microorganisms. Compounds 8a, 8b, 8c, 8e, 8f, 8i, and 8j exhibited good antimicrobial activity.

Journal ArticleDOI
TL;DR: Most of the compounds exhibit cytotoxicity against hepatic and colon tumor cells in a dose‐dependent mode and a relationship between the structure and their biological activity was observed.
Abstract: A series of new phenothiazinyl-thiazolyl-hydrazine derivatives were synthesized by Hantzsch cyclization of 1-(10-ethyl-10H-phenothiazin-3-yl)-methylidene-thiosemicarbazide with α-halocarbonyl derivatives. Comparison between classical and microwave assisted synthesis emphasizes the great advantages induced by microwaves irradiation which afforded high reaction yields in much shorter reaction time. Structural assignments were based on spectroscopic methods (high resolution NMR, FTIR, MS). The new compounds were tested in vitro for their antiproliferative activity against tumor cell lines using spectrometric methods. Most of the compounds exhibit cytotoxicity against hepatic and colon tumor cells in a dose-dependent mode and a relationship between the structure and their biological activity was observed.

Journal ArticleDOI
TL;DR: Compounds 1, 14, 15, 23, 26, 29a, 30 and 32 have the ability to protect DNA from the damage induced by bleomycin and were screened for their antioxidant properties.
Abstract: 4,6-Dimethyl-1H-pyrazolo[3,4-b]pyridine-3-amine (1) was used as a key intermediate for the synthesis of imidazolopyrazole derivatives 7-11 upon interaction with 3-(2-bromoacetyl)-2H-chromen-2-one (2), 2-(benzothiazol-2-yl)-4-chloro-3-oxobutanenitrile (3), 2,3-dibromonaphthalene-1,4-dione (4), naphtha[2,3-b]oxirene-2,7-dione (5), 2,5-dichloro-3,6-dihydroxyhexa-2,5-diene-1,4-dione (6), respectively. Acetylation of 11 afforded the bis-acetyl 12. Also, the imidazolopyrimidine 15 was prepared via treatment of 1 with sodium 3,4-dioxo-3,4-dihydronaphthalene-1-sulfonate (13) in DMF followed by cyclization of the bis-pyrazolopyrimidine 14 with glacial acetic acid. On the other hand, compound 1 was reacted with (E)-1-(4-methoxyphenyl)-5-(piperidin-1-yl)pent-1-en-3-one hydrochloride (16), 2-hydroxy-3-((piperidin-1-yl)-methyl)-naphthalene-1,4-dione (17), 2-styryl-2H-indene-1,3-dione (18), enaminone 22, chloroquinoline-3-carbaldehyde 27a, chloroquinoline-(6-methyl)-3-carbaldehyde 27b and 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde (28) to afford pyrazolo[3,4-a]pyrimidines 19-21, 23, 29a, 29b and 30, respectively. Also, the pyrazolopyrimidinone 33 was obtained via treatment of 1 with 1-cyanoacetyl-3,5-dimethylpyrazole (31) followed by cyclization of the formed intermediate 32 with glacial acetic acid. Finally, treatment of 1 with o-terephthalaldehyde in glacial acetic acid afforded diazepine 34. The newly synthesized compounds were screened for their antioxidant properties in which some of them exhibited promising activities. Compounds 1, 14, 15, 23, 26, 29a, 30 and 32 have the ability to protect DNA from the damage induced by bleomycin.