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1.
Vyakaranam K Rana G Spielvogel BF Maguire JA Hosmane NS 《Nucleosides, nucleotides & nucleic acids》2002,21(8-9):581-598
A number of substituted (borano) nucleic acids, 3'-[diethylphosphite(cyano, carboxy, or carbamoyl) borano] deoxynucleosides (3a-4c) and 5'-[diethylphosphite(cyano or carboxy) borano] deoxynucleosides (6a-7d) were prepared by a variety of synthetic procedures. The syntheses of the pyrophosphates (2a-2c), as precursors for 3a-4c, are also described. 相似文献
2.
《Nucleosides, nucleotides & nucleic acids》2013,32(5-8):1231-1234
Abstract Self-complementary {[5′-d(G-C)4]2} and non-selfcomplementary oligonucleotides [5′-d(TAG GTC AAT ACT) ? 3′-d(ATC CAG TTA TGA)] containing 7-(ω-aminoalkyn-1-yl)-7-deaza-2′-deoxyguanosines (1a–c) (1) and 7-deaza-2′-deoxyguanosine instead of dG were studied regarding their thermal stability as well as their phosphodiester hydrolysis by either 3′ → 5′- or 5′ → 3′ – phosphodi esterase studied by MALDI-TOF MS. 相似文献
3.
Mingzhang Gao Min Wang Qi-Huang Zheng 《Bioorganic & medicinal chemistry letters》2018,28(13):2234-2238
The reference standards methyl 3-((2,2-difluoro-5H-[1,3]dioxolo[4′,5′:4,5]benzo[1,2-d]imidazol-6-yl)carbamoyl)benzoate (5a) and N-(2,2-difluoro-5H-[1,3]dioxolo[4′,5′:4,5]benzo[1,2-d]imidazol-6-yl)-3-methoxybenzamide (5c), and their corresponding desmethylated precursors 3-((2,2-difluoro-5H-[1,3]dioxolo[4′,5′:4,5]benzo[1,2-d]imidazol-6-yl)carbamoyl)benzoic acid (6a) and N-(2,2-difluoro-5H-[1,3]dioxolo[4′,5′:4,5]benzo[1,2-d]imidazol-6-yl)-3-hydroxybenzamide (6b), were synthesized from 5-amino-2,2-difluoro-1,3-benzodioxole and 3-substituted benzoic acids in 5 and 6 steps with 33% and 11%, 30% and 7% overall chemical yield, respectively. Carbon-11-labeled casein kinase 1 (CK1) inhibitors, [11C]methyl 3-((2,2-difluoro-5H-[1,3]dioxolo[4′,5′:4,5]benzo[1,2-d]imidazol-6-yl)carbamoyl)benzoate ([11C]5a) and N-(2,2-difluoro-5H-[1,3]dioxolo[4′,5′:4,5]benzo[1,2-d]imidazol-6-yl)-3-[11C]methoxybenzamide ([11C]5c), were prepared from their O-desmethylated precursor 6a or 6b with [11C]CH3OTf through O-[11C]methylation and isolated by HPLC combined with SPE in 40–45% radiochemical yield, based on [11C]CO2 and decay corrected to end of bombardment (EOB). The radiochemical purity was >99%, and the molar activity (MA) at EOB was 370–740?GBq/μmol with a total synthesis time of ~40-min from EOB. 相似文献
4.
Anand R. Saundane Katkar Vijaykumar A. Verma Vaijinath 《Bioorganic & medicinal chemistry letters》2013,23(7):1978-1984
As a part of systematic investigation of synthesis and biological activities of indole analogues linked to various heterocyclic systems, we have synthesized new compounds viz., 2-amino-4-(5′-substituted 2′-phenyl-1H-indol-3′-yl)-6-aryl-4H-pyran-3-carbonitriles (2a–i), 4,5-diamino-6-(5′-substituted 2′-phenyl-1H-indol-3′-yl)-8-aryl-2-oxo-2,6-dihydrodipyrano [2,3-b:3,2-e]pyridine-3-carbonitriles (3a–i), 4-amino-5-(5′-substituted 2′-phenyl-1H-indol-3-yl)-7-aryl-1H-pyrano[2,3-d]pyrimidin-2(5H)-ones (4a–i), 4-amino-5-(5′-substituted 2′-phenyl-1H-indol-3′-yl)-7-aryl-1H-pyrano[2,3-d]pyrimidin-2(5H)-thiones (5a–i), 4-(5′-subtituted 2′-phenyl-1H-indol-3′-yl)-6-aryl-1,4-dihydropyrano[2,3-c]pyrazol-3-amines (6a–i) and 5-(5′-substituted 2′-phenyl-1H-indol-3′-yl)-7-aryl-3H-pyrano[2,3-d]pyrimidin-4(5H)-ones (7a–i). Antibacterial activity results revealed that, compound 6a showed promising activity versus Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae. Compound 6d exhibited good activity against S. aureus, K. pneumoniae and Pseudomonas aeruginosa. Antifungal activity results indicated that, compound 4d exhibited maximum zone of inhibition against Aspergillus oryzae and Aspergillus flavus. In case of antioxidant activity, compound 4a showed promising radical scavenging activity, ferric ions (Fe3+) reducing antioxidant power (FRAP) and metal chelating activity. 相似文献
5.
H. A. El-Sayed A. H. Moustafa A. Z. Haikal I. M. Abdou E. S. H. El-Ashry 《Nucleosides, nucleotides & nucleic acids》2013,32(9):1061-1071
Reaction of ethyl 4-thioxo-3,4-dihydropyrimidine-5-carboxylate derivatives 1a,b and ethyl 4-oxo-3,4-dihydropyrimidine-5-carboxylate 1c with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide in KOH or TEA afforded ethyl 2-aryl-4-(2′,3′,4′,6′-tetra-O-acetyl-β-D-glucopyranosylthio or/ oxy)-6-methylpyrimidine-5-carboxylate 6a-c. The glucosides 6a and 6b were obtained by the reaction of 1a and 1b with peracetylated glucose3 under MW irradiation. Mercuration of 1a followed by reaction with acetobromoglucose gave the same product 6a. The reaction of 1a-c with peracetylated ribose 4 under MW irradiation gave ethyl 2-aryl-4-(2′,3′,5′-tri-O-acetyl-β-D-ribofuranosylthio)-6-methylpyrimidine-5-carboxylate 8a–c. The deprotection of 6a–c and 8a–c in the presence of methanol and TEA/H2O afforded the deprotected products 7a–c and 9a–c. The structure were confirmed by using 1H and 13CNMR spectra. Selected members of these compounds were screened for antimicrobial activity. 相似文献
6.
《Journal of enzyme inhibition and medicinal chemistry》2013,28(5):649-656
Direct interaction between 7-chloro-1-cyclopropyl-6-fluoro-8-nitro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid and primary α-amino acids (exemplified by glycine, alanine, and l-valine) in aqueous ethanolic NaHCO3 at 70–80°C for 24–72?h produced the respective N-(4-oxoquinolin-7-yl)-α-amino acids (6a–c). The latter derivatives underwent reductive lactamization upon treatment with Na2S2O4 in aqueous ethanol to afford moderate yields of the corresponding pyrido[2,3-f]quinoxaline-8-carboxylic acids (8a–c). Acetylation of 8a–c using acetyl chloride afforded N4-acetylated hexahydro-2,7-dioxopyrido[2,3-f]quinoxaline-8-carboxylic acids (9a–c). The structures, assigned to these new heterocyclic products, are supported by analytical and spectral data. The synthesized compounds (6a–c/9a–c) showed appreciable antibacterial activity as compared with ciprofloxacin. 相似文献
7.
The branches of the shrub Aniba lancifolia Kubitzki et Rodrigues (Lauraceae) contain besides 2-hydroxy-4,5- dimethoxyallylbenzene and its dimer cyclohexan-2-allyl- 5-en-4,5-dimethoxy-4-O-(2′-allyl-4′,5′-dimethoxyphenyl)-1-one (lancilin, 2) 6 further novel neolignans: (4S,2′R)- and (4R,2′E)-cyclohexan-2-allyl-2,5-dien-4,5-dimethoxy-4-[2′-(1′-guaiacyl)-propyl]-1-one (lancifolins A and B, 3a and 3b), (4S,2′R)- and (4R,2′R)-cyclohexan- 2-allyl-2,5-dien-4,5-dimethoxy-4-[2′-(1′-veratryl)-propyl]-1-one (lancifolins C and D, 3c and 3d), (4S,2′R)-and (4R,2′R)-cyclohexan-2-allyl-2,5-dien-4,5-dimethoxy-4-[2′-(1′-piperonyl)-propyl]-1-one (lancifolins E and F, 3e and 3f). 相似文献
8.
Zhongli Gao William J. Hurst Etienne Guillot Raisa Nagorny Marie-Pierre Pruniaux James A. Hendrix Pascal G. George 《Bioorganic & medicinal chemistry letters》2013,23(14):4044-4047
This Letter describes the asymmetric synthesis of the four stereoisomers (8a–8d) of a potent and highly selective histamine H3 receptor (H3R) antagonist, 5-fluoro-2-methyl-N-[2-methyl-4-(2-methyl[1,3′]bipyrrolidinyl-1′-yl) phenyl]benzamide (1). The physico-chemical properties, in vitro H3R affinities and ADME of 8a–8d were determined. Stereoisomer 8c (2S,3′S) displayed superior in vitro H3R affinity over other three stereoisomers and was selected for further profiling in in vivo PK and drug safety. Compound 8c exhibited excellent PK properties with high exposure, desired brain to plasma ratio and reasonable brain half life. However, all stereoisomers showed similar unwanted hERG affinities. 相似文献
9.
Asif Husain Diwakar Madhesia Mohd Rashid Aftab Ahmad 《Journal of enzyme inhibition and medicinal chemistry》2016,31(6):1682-1689
A series of new 6-substituted-N-[3-{2-(substituted phenyl)-ethenyl} quinoxaline-2(1H)-ylidene]-1,3-benzothiazole-2-amine (4a–f) were designed and synthesized by condensing 2-amino-benzothiazole-6-sulfonic acid amide (1) with chalcones of quinoxaline-2-one (3a–f) in a hope to obtain promising and a new class of diuretic agents. Structures of all the newly synthesized compounds were characterized by spectral data and elemental analysis. The pharmacological studies in experimental rats indicates that compound 4c possesses excellent in vivo diuretic activity of 1.13 and appears to be a better diuretic agent than the reference drugs, acetazolamide (1.0) and urea (0.88). Insight of the binding mode of the synthesized compounds (ligand) into the binding sites of carbonic anhydrase enzyme (PDF code: 4KUV) was provided by docking studies, performed with the help of Maestro 9.0 docking software. Further pharmacokinetic and toxicological studies are needed to confirm the safety of compound 4c which emerged as a lead diuretic compound. 相似文献
10.
Jack D. Anderson Roland K. Robins Ganapathi R. Revankar 《Nucleosides, nucleotides & nucleic acids》2013,32(5):853-863
Abstract The synthesis of pyrazolo[3,4-d]pyrimidine ribonucleoside 3′, 5′-cyclic phosphates related to cAMP, cIMP and cGMP has been achieved for the first time. Phosphorylation of 4-amino-6-methylthio-1-β-D-ribo-furanosylpyrazolo[3,4-d]pyrimidine (1) with POCl3 in trimethyl phosphate gave the corresponding 5′-phosphate (2a). DCC mediated intramolecular cyclization of 2a gave the corresponding 3′, 5′-cyclic phosphate (3a), which on subsequent dethiation provided the cAMP analog 4-amino-1-β-D-ribofuranosylpyrazolo[3, 4-d]pyrimidine 3′, 5′-cyclic phosphate (3b). A similar phosphorylation of 6-methylthio-1-β-D-ribofuranosylpyrazolo[3, 4-d]pyrimidin-4(5H)-one (5), followed by cyclization with DCC gave the 3′, 5′-cyclic phosphate of 5 (9a). Dethiation of 9a with Raney nickel gave the cIMP analog 1-β-D-ribofuranosylpyrazolo[3, 4-d]pyrimidin-4(5H)-one 3′, 5′-cyclic phosphate (9b). Oxidation of 9a with m-chloroperoxy benzoic acid, followed by ammonolysis provided the cGMP analog 6-amino-1-β-D-ribofuranosylpyrazolo [3, 4-d] pyrimidin-4(5H)-one 3′, 5′-cyclic phosphate (7). The structural assignment of these cyclic nucleotides was made by UV and H NMR spectroscopic studies. 相似文献
11.
《Journal of enzyme inhibition and medicinal chemistry》2013,28(6):1344-1350
A number of new 8-substituted-4-(2/4-substituted phenyl)-2H-[1,3,5]triazino[2,1-b][1,3]benzothiazole-2-thiones (4a–t) were synthesized and evaluated for their anticonvulsant, anti-nociceptive, hepatotoxic, and neurotoxic properties. The titled compounds (4a–t) were obtained by cyclization of N-{[6-substituted-1,3-benzothiazol-2-yl)amino]carbonothioyl}-2/4-substituted benzamides (3a–t) by refluxing in n-butanol. All the newly synthesized compounds were screened for their anticonvulsant activity in a mouse seizure model and were compared with the standard drug phenytoin. Compounds 4a, 4c, 4f, and 4l showed complete protection after time periods of 0.5?h and 4?h. Some of the selected compounds were evaluated for their neurotoxic and hepatotoxic effects, and none of these showed any sign of neurotoxicity or hepatotoxicity. Compounds 4a–t were also evaluated for their anti-nociceptive activity by a thermal stimulus technique using diclofenac as standard. Compounds 4o, 4q, and 4t displayed highly potent analgesic activity with p?<?0.01. 相似文献
12.
1H-Pyrrolo[2′,3′:4,5]furo[3,2-c]pyridine-2-carboxylic acid (6a) and its 1-methyl (6b) and 1-benzyl (6c) derivatives were synthesized. 3-(5-Methoxycarbonyl-4H-furo[3,2-b]-pyrrole-2-yl)propenoic acid (1) was converted to the corresponding azide 2, which in turn was cyclized to give 3 by heating in diphenylether. The pyridone 3 obtained was aromatized with phosphorus oxychloride, then reduced with zinc in acetic acid to give methyl 1H-pyrrolo[2′,3′:4,5]furo[3,2-c]pyridine-2-carboxylate (5), which by hydrolysis gave the corresponding carboxylic acid 6a. 相似文献
13.
B. Azmy P. Fernández-resa P. Goya R. Nieves C. Ochoa M. Stud 《Nucleosides, nucleotides & nucleic acids》2013,32(4):325-337
Abstract Synthesis of methyl, glucosyl and ribosyl derivatives of 7-amino-2H, 4H-[1, 2, 3]triazolo [4, 5-c] [1, 2, 6] thiadiazine 5, 5-dioxide (1a) and 7-amino-4H- [1, 2, 5] thiadiazolo [3, 4-c][1, 2, 6] thiadiazine 5, 5-dioxide (2a) is described. The structures of the glycosyl derivatives are discussed on the basis of their PMR- and UV-spectroscopic data. 相似文献
14.
Abstract The reaction of the 2′,3′-lyxoepoxide (1) with ammonium azide gives two products; namely, the 3′-arabino azide (2a) and in low yield 2′-xylo azide (3a). After debenzoylation and reduction the resulting mixture of amines was resolved by chromatography on a weak cation exchanger, Amberlite IRC-50, and afforded crystalline 1-(3-amino-3-deoxy-β-D-arabinofuranosyl)uracil (2c) and 1-(2-amino-2-deoxy-β-D-xylofuranosyl)uracil (3c) in the ratio of 4:1. 相似文献
15.
Abstract Methyl 2-[4-methoxycarbonyl-5-(β-D-ribofuranosyl)-1H-pyrazolyl-3]-acetate (7a) obtained from ribofuranosyltetrazole 3 by conjugative addition to dimethyl 1,3-allenedicarboxylate or dimethyl 3-chloro-2-pentenedioate after electrocyclization of 2-propenyltetrazole 5 was used as a suitable intermediate to provide pyrazolo [4,3-c]pyridine C-ribonucleosides 1 and 2 related to 7-substituted 3-deazaxanthosine and -guanosine analogs. 相似文献
16.
Tomokazu Sugawara Toyoaki Ishikura Tokuo Itoh Yoshihisa Mizuno 《Nucleosides, nucleotides & nucleic acids》2013,32(3):239-251
Abstract 9-β-D-Arabinofuranosyldeazaadenines [1-deaza-araA (4a) and 3-deaza-araA (4b)] were prepared from 6-chloro-β-D-ribofuranosyl-1- (6a) and -3-deazapurine (6b), respectively. Synthesis of 2′-deoxy-1-deaza-adenosine (5a) from 1-deazaadenosine (6c) is also described. 相似文献
17.
E. S. H. El Ashry N. Rashed A. Abdel-Rahman L. F. Awad H. A. Rasheed 《Nucleosides, nucleotides & nucleic acids》2013,32(8):925-939
Alkylation of 2-methylthiopyrimidin-4(1H)-one (1a) and its 5(6)-alkyl derivatives 1b–d as well as theophylline (7) with 2,2-bis(bromomethyl)-1,3-diacetoxypropane (2) under microwave irradia-tion gave the corresponding acyclonucleosides 1-[(3-acetoxy-2-acetoxymethyl-2-bromomethyl)prop-1-yl]-2-methyl-thio pyrmidin-4(1H)-ones 3a–d and 7-[(3-acetoxy-2-acetoxymethyl-2-bromomethyl)prop-1-yl]theophylline (8), which upon further irradiation gave the double-headed acyclonucleosides 1,1 ′-[(2,2-diacetoxymethyl)-1,3-propylidene]-bis[(2-(methylthio)-pyrimidin-4(1H)-ones] 4a–c, and 7,7 ′-[(2,2-diacetoxymethyl)-1,3-propylidene]-bis(theophylline) (9). The deacetylated derivatives were obtained by the action of sodium methoxide. The activity of deacetylated nucleosides against Hepatitis B virus was evaluated. Compound 5b showed moderate inhibition activity against HBV with mild cytotoxicity. 相似文献
18.
Tun-Cheng Chien David A. Berry John C. Drach Leroy B. Townsend 《Nucleosides, nucleotides & nucleic acids》2013,32(10-12):1971-1996
3-Amino-6-(β-D-ribofuranosyl)imidazo[4,5-c]pyrazole (2) was synthesized via an N-N bond formation strategy by a mononuclear heterocyclic rearrangement (MHR). A series of 5-amino-1-(5-O-tert-butyldimethylsilyl-2,3-O-isopropylidene-β-D-ribofuranosyl-4-(1,2,4-oxadiazol-3-yl)imidaz-oles (6a-d), with different substituents at the 5-position of the 1,2,4-oxadiazole, were synthesized from 5-amino-1-(β-D-ribofuranosyl)imidazole-4-carboxamide (AICA Ribose, 3). It was found that 5-amino-1-(5-O-tert-butyldimethylsilyl-2,3-O-isopropylidene-β-D-ribofuranosyl)-4-(5-methyl-1,2,4-oxadiazol-3-yl)imidazole (6a) underwent the MHR with sodium hydride in DMF or DMSO to afford the corresponding 3-acetamidoimidazo[4,5-c]pyrazole nucleoside(s) (7b and/or 7a) in good yields. A direct removal of the acetyl group from 3-acetamidoimidazo[4,5-c]pyrazoles under numerous conditions was unsuccessful. Subsequent protecting group manipulations afforded the desired 3-amino-6-(β-D-ribofuranosyl)imidazo[4,5-c]pyrazole (2) as a 5:5 fused analog of adenosine (1). 相似文献
19.
Frank Seela Matthias Zulauf Georg Becher 《Nucleosides, nucleotides & nucleic acids》2013,32(3):305-314
Abstract The anion-glycosylation (KOH, MeCN, TDA-1) of 3-bromopyrazolo[3,4-d]-pyrimidines 4a and 4b with 2-deoxy-3,5-di-O-(p-toluoyl)-α-D-erythro-pentofuranosyl chloride (5) furnishes the regioisomeric N′-β-D-2′-deoxyribonucleosides 6a and 6b together with the dehalogenated N2-regioisomers 8a and 8b, stereoselectively. The dehalogenation takes place after the glycosylation and results from the sensitivity of the N-2 nucleosides toward aqueous base. An addition/elimination mechanism is suggested for the dehalogenation reaction. 相似文献
20.
Shaikha S. Al-Neyadi Ahmed H. Hassan Ibrahim M. Abdou 《Nucleosides, nucleotides & nucleic acids》2013,32(2):120-134
A new series of substituted 2(1H)-pyridones (4a–i) and their glucosides (5, 6a–e) were prepared as potential agents against leukemia (HL-60) cells. Glucosides (5,6a–e) were synthesized using three independent methods. Microwave protocol as an ecologically new method was used to synthesize the target compounds. Structures of the new products were confirmed using one- and two-dimensional NMR spectroscopy. In vitro exposure of pyridones substituted at position 4 with a 2-thienyl or 2-(trifluoromethyl)phenyl were found to exhibit high antiproliferation activities; in particular, 3-cyano-4-(thien-2′-yl)-6-(4″-chlorophenyl)-2(1H)-pyridone (4c) and its glucoside analogue (6c) had the highest activity. 相似文献