Chloroplast Replication in Euglena gracilis Grown in Cadmium-Ion Containing Media

N-(1-Alkenyl)-2-chIoroacetamides, which bear an aryl substituent at the 1-position of the alkenyl moiety, were synthesized and their herbicidal activities were tested. Some of them were active against paddy field weeds. In particular, a new type of chloroacetamide herbicide, 2-chloro-N-methyl-N-(2-methyl-1-phenylpropen-1-yl)acetamide, having no 2,6-dialkyl substituted phenyl moiety, which has been considered essential for activity, was found to be active against barnyardgrass.     

Synthesis of pro-apoptotic indapamide derivatives as anticancer agents

Abstract

4-Chloro-3-({[(substitutedamino)carbonothioyl]amino}sulfonyl)-N-(2-methyl-2,3-dihydro-1H-indole-1-yl)benzamide (1–20) and 4-chloro-3-({[3-(substituted)-4-oxo-1,3-thiazolidine-2-ylidene]amino}sulfonyl)-N-(2-methyl-2,3-dihydro-1H-indole-1-yl)benzamide derivatives (21–31) were synthesized from 4-chloro-N-(2-methyl-2,3-dihydroindol-1-yl)-3-sulfamoylbenzamide (indapamide). 4-Chloro-3-({[(4-chlorophenyl) amino) carbonothioyl]amino}sulfonyl)-N-(2-methyl-2,3-dihydro-1H-indole-1-yl)benzamide 12 demonstrated the highest proapoptotic activity among all synthesized compounds on melanoma cell lines MDA–MB-435 with 3.7% growth inhibition at the concentration of 10?µM. Compound 12 (SGK 266) was evaluated in vitro using the MTT colorimetric method against melanoma cancer cell line MDA–MB435 growth inhibition for different doses and exhibited anticancer activity with IC₅₀ values of 85–95?µM against melanoma cancer cell line MDA–MB435. In addition, this compound was investigated as inhibitors of four physiologically relevant human carbonic anhydrase isoforms, hCA I, II, IX and XII. The compund inhibited these enzymes with IC₅₀ values ranging between 0.72 and 1.60?µM.     

Synthesis,antimicrobial activity and cytotoxicity of some new carbazole derivatives

In this work, some N-(9-Ethyl-9H-carbazole-3-yl)-2-(phenoxy)acetamide derivatives were synthesised and evaluated for their antimicrobial activity and cytotoxicity. The structural elucidation of the compounds was performed by IR, ¹H-NMR, ¹³C-NMR and FAB⁺-MS spectral data and elemental analyses. The title compounds were obtained by reacting 2-chloro-N-(9-ethyl-9H-carbazole-3-yl)acetamide with some substituted phenols. The synthesised compounds were investigated for their antibacterial and antifungal activities against Micrococcus luteus, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Listeria monocytogenes and Candida albicans. The compounds N-(9-Ethyl-9H-carbazole-3-yl)-2-(4-ethylphenoxy)acetamide (2c) and N-(9-Ethyl-9H-carbazole-3-yl)-2-(quinolin-8-yloxy)acetamide (2n) showed notable antimicrobial activity. The compounds were also studied for their cytotoxic effects using MTT assay, and it was seen that 2n had the lowest cytotoxic activity against NIH/3T3 cells.     

N-aryl 2-aryloxyacetamides as a new class of fatty acid amide hydrolase (FAAH) inhibitors

Fatty acid amide hydrolase (FAAH) is a promising target for the development of drugs to treat neurological diseases. In search of new FAAH inhibitors, we identified 2-(4-cyclohexylphenoxy)-N-(3-(oxazolo[4,5-b]pyridin-2-yl)phenyl)acetamide, 4g, with an IC₅₀ of 2.6?µM as a chemical starting point for the development of potent FAAH inhibitors. Preliminary hit-to-lead optimisation resulted in 2-(4-phenylphenoxy)-N-(3-(oxazolo[4,5-b]pyridin-2-yl)phenyl)acetamide, 4i, with an IC₅₀ of 0.35?µM.     

Facile synthesis of SSR180575 and discovery of 7-chloro-N,N,5-trimethyl-4-oxo-3(6-[18F]fluoropyridin-2-yl)-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide,a potent pyridazinoindole ligand for PET imaging of TSPO in cancer

A novel synthesis of the translocator protein (TSPO) ligand 7-chloro-N,N,5-trimethyl-4-oxo-3-phenyl-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide (SSR180575, 3) was achieved in four steps from commercially available starting materials. Focused structure–activity relationship development about the pyridazinoindole ring at the N3 position led to the discovery of 7-chloro-N,N,5-trimethyl-4-oxo-3(6-fluoropyridin-2-yl)-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide (14), a novel ligand of comparable affinity. Radiolabeling with fluorine-18 (¹⁸F) yielded 7-chloro-N,N,5-trimethyl-4-oxo-3(6-[¹⁸F]fluoropyridin-2-yl)-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide ([¹⁸F]-14) in high radiochemical yield and specific activity. In vivo studies of [¹⁸F]-14 revealed this agent as a promising probe for molecular imaging of glioma.     

The first radiosynthesis of [11C]AZD8931 as a new potential PET agent for imaging of EGFR,HER2 and HER3 signaling

The reference standard AZD8931{2-(4-((4-((3-chloro-2-fluorophenyl)amino)-7-methoxyquinazolin-6-yl)oxy)piperidin-1-yl)-N-methylacetamide} (11a) was synthesized from methyl 4,5-dimethoxy-2-nitrobenzoate or ethyl 4,5-dimethoxy-2-nitrobenzoate and 2-chloro-N-methylacetamide in 11 steps with 2–5% overall chemical yield. The precursor N-desmethyl-AZD8931{2-(4-((4-((3-chloro-2-fluorophenyl)amino)-7-methoxyquinazolin-6-yl)oxy)piperidin-1-yl)acetamide} (11b) was synthesized from methyl 4,5-dimethoxy-2-nitrobenzoate or ethyl 4,5-dimethoxy-2-nitrobenzoate and 2-bromoacetamide in 11 steps with 2–4% overall chemical yield. The target tracer [¹¹C]AZD8931 {2-(4-((4-((3-chloro-2-fluorophenyl)amino)-7-methoxyquinazolin-6-yl)oxy)piperidin-1-yl)-N-[¹¹C]methylacetamide} ([¹¹C]11a) was prepared from N-desmethyl-AZD8931 (11b) with [¹¹C]CH₃OTf under basic condition (NaH) through N-[¹¹C]methylation and isolated by HPLC combined with solid-phase extraction (SPE) in 40–50% radiochemical yield based on [¹¹C]CO₂ and decay corrected to end of bombardment (EOB) with 370–1110 GBq/μmol specific activity at EOB.     

Synthesis of 5-Methyl-2′-O-Deoxycytidine Analogs to Determine Monoclonal Antibody Specificity in the Recognition of the 6-(p-Bromobenzoylamino) Caproyl Radical

Abstract

Eight new p-bromobenzoyl derivatives of 5-methyl-2′-O-deoxycytidine analogs, substituted at the 4-position, were synthesized. The best conditions for obtaining 5-methyl-4-N-aminoalkyl-2′-O-deoxycytidine from 3′,5′-di-O-acetyl-4–(1,2,4-triazol-1-yl)-2′-O-deoxythymidine were studied. The nucleoside analogs were used to identify the fragment of the 6-(p-bromobenzoylamino)caproyl radical that binds to the monoclonal antibody obtained against it and to define an affinity scale of monoclonal antibody against them.     

Evaluation of coupling conditions for the incorporation of Nα-Fmoc-Tyr(PO3H2)-OH in solid-phase peptide synthesis

Summary In order to minimise the formation of the pyrophosphate derivative of the target peptide when side-chain-unprotected phopshotyrosine is used in solid-phase peptide synthesis, this building block can be incorporated using benzotriazolyloxy-tris-(dimethylamino)phosphonium hexafluorophosphate/1-hydroxybenzotriazole/N-methylmorpholine (1:1:2.3) in the presence of a chaotropic salt (0.4 M LiCl in N-methyl-2-pyrrolidinone).Abbreviations BOP benzotriazolyloxy-tris-(dimethylamino)phosphonium hexafluorophosphate - DIEA diisopropylethylamine - Fmoc 9-fluorenylmethoxycarbony - HATU N-[(dimethylamino)1H-1,2,3-triazolo[4,5-b]pyridin-1-ylmethylene]-N-methylmethan-aminium hexafluorophosphate N-oxide - HOBt 1-hydroxybenzotriazole - HPLC high-performance liquid chromatography - MALDI-TOF matrix-assisted laser-desorption ionization time-of-flight mass spectrometry - NMM N-methylmorpholine - NMP N-methyl-2-pyrrolidinone - Pmc 2,2,5,7,8-pentamethyl-chroman-6-sulfonyl - ® solid support - TFA trifluoroacetic acid - TPTU 2-(2-pyridon-1-yl)-1,1,3,3-tetramethyluroniumfluoroborate. Abbreviations used for amino acids follow the recommendations of the IUPAC-IUB Commission of Biochemical Nomenclature [Eur. J. Biochem., 138 (1984) 9]     

Synthesis,antitumor activity and molecular docking study of some novel 3-benzyl-4(3H)quinazolinone analogues

A novel series of 3-benzyl-substituted-4(3H)-quinazolinones were designed, synthesized and evaluated for their in vitro antitumor activity. The results of this study demonstrated that 2-(3-benzyl-6-methyl-4-oxo-3,4-dihydroquinazolin-2-ylthio)-N-(3,4,5-trimethoxyphenyl)acetamide, 2-(3-benzyl-6,7-dimethoxy-4-oxo-3,4-dihydroquinazolin-2-ylthio)-N-(3,4,5-trimethoxyphenyl)acetamide and 3-(3-benzyl-6-methyl-4-oxo-3,4-dihydroquinazolin-2-ylthio)-N-(3,4,5-trimethoxyphenyl)-propanamide have shown amazing broad spectrum antitumor activity with mean GI₅₀ (10.47, 7.24 and 14.12?µM. respectively), and are nearly 1.5–3.0-fold more potent compared with the positive control 5-FU with mean GI₅₀, 22.60?µM. On the other hand, compounds 6 and 10 yielded selective activities toward CNS, renal and breast cancer cell lines, whereas compound 9 showed selective activities towards leukemia cell lines. Molecular docking methodology was performed for compounds 7 and 8 into ATP binding site of EGFR-TK which showed similar binding mode to erlotinib, while compound 11 into ATP binding site of B-RAF kinase inhibited the growth of melanoma cell lines through inhibition of B-RAF kinase, similar to PLX4032.     

Anti-Food Allergic Alkaloids from the Lotus Seed Pot

Lotus seed pod (LSP) has been used as traditional herbal cuisine to modulate immunity. From the AcOEt-soluble extract of LSP, one new aporphine alkaloid, N-[2-(2H-phenanthro[3,4-d][1,3]dioxol-5-yl)ethyl]acetamide (nelunucine A, 1 ) was obtained along with 19 known ones. Their structures were established by detailed analysis of the 1D-, 2D-NMR, and HR-ESI-MS data. N-Nornuciferine ( 9 ) and lirinidine ( 10 ) showed potent in vitro anti-food allergic activity with IC₅₀ values of 40.0 and 55.4 μM, respectively, compared to 91.4 μM for loratadine, the positive control.     

Synthesis of novel selenium containing sulfa drugs and their antibacterial activities

Synthesis of 3-[4-(N-substituted sulfamoyl)phenyl]-3,4-dihydro-4-oxo-7,9-dimethylpyri-do[3′,2′:4,5]selenolo[3,2-d]pyrimidines,7-[4-(N-substituted sulfamoyl)phenyl]-7,8-dihydro-8-oxo-3,4-diphenylpyrimido[4′,5′:4,5]selenolo [2,3-c]pyridazines and 1-[4-(N-substituted sulfamoyl)phenyl]-1,11-dihydro 11-oxo-4-methylpyrimido[4′,5′:4,5]selenolo[2,3-b]quinolines is reported. 4-Amino-N-pyrimidine-2-ylbenzene sulfonamide (a), 4-amino-N-(2,6-dimethylpyrimidin-4-yl)benzene sulfonamide (b), N-[(4-aminophenyl)sulfonyl] acetamide (c) with N-ethoxymethyleneamino of selenolo pyridine, selenolo pyridazine and selenolo quinoline derivatives respectively were obtained starting from 1-amino-N ⁴-substituted sulfanilamides. Spectroscopic data (IR, ¹H NMR, ¹³C NMR and Mass spectral) confirmed the structure of the newly synthesized compounds. Substituted pyrimidines, pyridazines and quinolines were screened for antibacterial activity against gram-positive and gram-negative bacteria. Selenolo derivative of N-[(4-aminophenyl)sulfonyl] acetamide (substitutent of sulfacetamide c) showed strong bactericidal effect against all the tested organisms. Selenolo[3,2-d]pyrimidin (substitutent a) showed a good bactericidal effect against Serratia marcescens, Staphylococcus aureus and Escherichia coli. Compounds selenolo[2,3-c]pyridazine (substitutent b), selenolo[2,3-b]quinoline(substitutents c)) exhibited a moderate bactericidal effect against Serratia marcescens. None of the synthesized seleno pyridazines has a considerable antimicrobial activity against the tested organisms. The minimum inhibitory concentration (MIC) of the most active compound-3-[4-(N-acetyl sulfamoyl)phenyl]-3,4-dihydro-4-oxo-7,9-dimethylpyrido[3′,2′:4,5]selenolo [3,2-d]pyrimidine was 10 mg ml⁻¹.     

Highly enantioselective bioreduction of N-methyl-3-oxo-3-(thiophen-2-yl) propanamide for the production of (S)-duloxetine

Whole cells of Rhodotorula glutinis reduced N-methyl-3-oxo-3-(thiophen-2-yl) propanamide at 30 g/l to (S)-N-methyl-3-hydroxy-3-(2-thienyl) propionamide, an intermediate in the production of (S)-duloxetine, a blockbuster antidepressant drug, in 48 h. The reaction had excellent enantioselectivity (single enantiomer, >99.5% enantiomeric excess [ee]) with a >95% conversion.     

N-Acetyldopamine derivatives from Periostracum Cicadae

Five new N-acetyldopamine (NADA) derivatives (1–5) and one known NADA quinone methide (6) were isolated from Periostracum Cicadae (the cast-off shell of the cicada Cryptotympana pustulata Fabricius), which is known as chantui in China and is used in traditional Chinese medicine to treat soreness of the throat, hoarseness, itching, and spasms. By combined analysis of one-dimensional and two-dimensional nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, CD spectra, and chemical evidence, the structures of the isolated compounds were established as (R)-N-(2-(3,4-dihydroxyphenyl)-1-ethoxy-2-oxoethyl)acetamide (1), (1R,2R)-N-(1,2-diethoxy-2-(3,4-dihydroxyphenyl)-ethyl)acetamide (2), (R)-N-(1-acetamido-2-ethoxy-2-(3,4-dihydroxyphenyl)-ethyl)acetamide (3), (1R,2R)-N-(2-(3,4-dihydroxyphenyl)-2-ethoxy-1-methoxyethyl)acetamide (4), (1S,2S)-N-(2-(3,4-dihydroxyphenyl)-2-ethoxy-1-methoxyethyl)acetamide (5), and (R)-N-(2-(3,4-dihydroxyphenyl)-2-methoxyethyl)acetamide (6).     

A substrate for the fluorogenic assay of exo-beta-N-acetylmuramidase: synthesis and purification of 4-methylumbelliferyl N-acetylmuramide.

A fluorogenic substrate for exo-β-N-acetylmuramidase from Bacillus subtilis B was synthesized. 4-Methyl-2-oxo-1,2-benzopyran-7-yl 2-acetamido-4,6-O-benzylidene-2-deoxy-β-d-glucopyranoside was prepared from 4-methyl-2-oxo-1,2-benzopyran-7-yl 2-acetamido-2-deoxy-β-d-glucopyranoside, condensed with dl-2-chloropropionic acid, the benzylidene residue removed by acetolysis and the 4-methyl-2-oxo-1,2-benzopyran-7-yl 2-amino-3-O-(d-1-carboxyethyl)-2-deoxy-β-d-glucopyranoside purified by chromatography on silica gel and Sephadex G-10 and by high-voltage paper electrophoresis. The identity of the product was confirmed by pmr studies, acid hydrolysis followed by chromatography of the products, and enzymic digestion.     

Synthesis and structure–activity relationships of N-aryl(indol-3-yl)glyoxamides as antitumor agents

The synthesis and study of the structure–activity relationships of cytotoxic compounds based on N-pyridinyl or N-aryl-2-(1-benzylindol-3-yl)glyoxamide skeleton, represented by the lead structures D-24241 and D-24851, are described. The presence of N-(pyridin-4-yl) moiety was crucial for activity and 2-[1-(4-chloro-3-nitrobenzyl)-1H-indol-3-yl]-2-oxo-N-(pyridin-4-yl)acetamide (55), the most potent derivative, showed IC₅₀ = 39 nM, 51 nM and 11 nM against HeLa/KB (human cervix carcinoma), L1210 (murine leukemia) and SKOV3 (human ovarian carcinoma) cell lines proliferation assay, respectively, as active as the lead compounds.     

Novel limonene and citral based 2,5-disubstituted-1,3,4-oxadiazoles: A natural product coupled approach to semicarbazones for antiepileptic activity

Two novel series of N⁴-(5-(2/3/4-substituted-phenyl)-1,3,4-oxadiazol-2-yl)-N¹-(2-methyl-5-(prop-1-en-2-yl)cyclohex-2-enylidene)semicarbazide and N⁴-(5-(2/3/4-substituted-phenyl)-1,3,4-oxadiazol-2-yl)-N¹-(3,7-dimethylocta-3,6-dienylidene)-semicarbazide were synthesized to meet structural prerequisite indispensable for anticonvulsant activity. The anticonvulsant activities of the compounds were investigated using maximal electroshock seizure (MES), subcutaneous pentylenetrtrazole (scPTZ) and subcutaneous strychnine (scSTY) models. The rotorod test was conducted to evaluate neurotoxicity. Some of the selected active compounds were subjected to GABA assay to confirm their mode of action. The outcome of the present investigations proved that the four binding sites pharmacophore model is vital for anticonvulsant activity. The efforts were also made to establish structure–activity relationships among test compounds.     

A Facile Synthesis of the Phosphoramidites of 2-N-Methyl-2′-deoxy (or 2′-O-allyl)-ψ-isocytidine, 1, 3-Dimethyl-2′-deoxy-ψ-uridine and N1-Methyl-2′-O-allyl-ψ-uridine as Synthons Suitable for Oligonucleotide Synthesis

Abstract

An efficient and facile syntheses of 5′-O-(4, 4′-dimethoxytrityl)-3′-[2-cyanoethyl bis(1-methylethyl)]phosphoramidites of 2-N-methyl-2′-deoxy-ψ-isocytidine (6), 2-N-methyl-2′-deoxy-α-ψ-isocytidine (13), 2-N-methyl-2′-O-allyl-ψ-isocytidine (11), 1, 3-dimethyl-2′-deoxy-ψ-uridine (4) and N1-methyl-2′-O-allyl-ψ-uridine (19) have been accomplished in good overall yields. The pyrimidine-pyrimidine transformation reaction was found to be useful for the preparation of 2-N-methyl-2′-O-allyl-ψ-isocytidine (10). The utility of these novel phosphoramidites is demonstrated by their incorporation into oligonucleotides via solid-support, oligonucleotide methodology.     

Indomethacin derivatives as tubulin stabilizers to inhibit cancer cell proliferation

Cyclooxygenase (COX) inhibitor Indomethacin analogs exhibited more potent cancer cell growth inhibition and apoptosis inducing activities than the parental compound. The anti-proliferative mechanism investigation of the analogs revealed that they inhibited tubulin polymerization at high concentrations whereas enhanced polymerization at low concentrations. The two opposite activities might antagonize each other and impaired the anti-proliferative activity of the derivatives eventually. In this study, we further performed lead optimization based on the structure activity relationship (SAR) generated. One of the new Indomethacin derivatives compound 11 {2-(4-(benzyloxy)phenyl)-N-(1-(4-bromobenzoyl)-3-(2-((2-(dimethylamino)ethyl)amino)-2-oxoethyl)-2-methyl-1H-indol-5-yl)acetamide} inhibited the proliferation of a panel of cancer cell lines with IC₅₀s at the sub-micromole levels. Further study revealed that the compound only enhanced tubulin polymerization and was a tubulin stabilizer.     

Structure-based design of imidazo[1,2-a]pyrazine derivatives as selective inhibitors of Aurora-A kinase in cells

Co-crystallisation of the imidazo[1,2-a]pyrazine derivative 15 (3-chloro-N-(4-morpholinophenyl)-6-(pyridin-3-yl)imidazo[1,2-a]pyrazin-8-amine) with Aurora-A provided an insight into the interactions of this class of compound with Aurora kinases. This led to the design and synthesis of potent Aurora-A inhibitors demonstrating up to 70-fold selectivity in cell-based Aurora kinase pharmacodynamic biomarker assays.     

Fully automated synthesis and initial PET evaluation of [11C]PBR28

Fully automated synthesis and initial PET evaluation of a TSPO radioligand, [¹¹C]PBR28 (N-(2-[¹¹C]methoxybenzyl)-N-(4-phenoxypyridin-3-yl)acetamide), are reported. These results facilitate the potential preclinical and clinical PET studies of [¹¹C]PBR28 in animals and humans.