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Abstract The diastereoisomers 2a, 2b and their 2-thio analogues 4a and 4b were obtained by three-step transformation of uridine and 2-thiouridine, respectively. The absolute configuration at C-51 in 2a and 2b was established by CD, while for 4a and 4b the configurational assignment was based on the chemical correlation. The acids 1 and 3 were obtained by alkaline hydrolysis of 2a and 4a, respectively. 相似文献
3.
Krzysztof W. Pankiewicz Kyoichi A. Watanabe 《Nucleosides, nucleotides & nucleic acids》2013,32(5):613-624
Abstract Treatment of ψ-uridine (3) with α-acetoxyisobutyryl chloride in acetonitrile gave, after deprotection, a mixture of four products: 5-(2-chloro-2-deoxy-β-D-arabinofuranosyl)uracil (10a), its 3′-chloro xylo isomer (11a), 2′-chloro-2′-deoxy-ψ-uridine (9a) and 4,2′-anhydro-ψ-uridine (8a). Each component was isolated by column chromatography. Compound 9 was converted to the known 1,3-dimethyl derivative 2 by treatment with DMF-dimethylacetal. Treatment of 10 and 11 with NaOMe/MeOH afforded the same 4,2′-anhydro-C-nucleoside 8. The 1,3-dimethyl analogues of 10 and 11, however, were converted to 2′,3′-anhydro-1,3-dimethyl-ψ-uridine (13) upon base treatment. The epoxide 13 was also prepared in good yield by treatment of 10 and 11 with DMF-dimethylacetal. 相似文献
4.
Jiří žemlička 《Nucleosides, nucleotides & nucleic acids》2013,32(3):245-264
Abstract New analogues of antiviral agents 9-(2, 3-dihy-droxyproply) adenine (DHPA, 1a.) and 9-(2-hydroxyethoxymethyl) guanine (acyclovir, Ib) - compounds Ic and Id were prepared and their biological activity was investigated. Racemic 1, 2, 4-butanetriol (2) was converted to the corresponding benzylidene derivative (3a) by acetalation with benzalde-hyde and triethyl orthoformate. Acetal 3a and p-toluene- sul-fonyl chloride in pyridine gave the corresponding p-toluenes fonate 3b. Alkylation of adenine 5a via sodium salt of 5a with 3b in dimethylformamide or in the presence of tetra-n-butylammonium fluoride in tetrahydrofuran gave intermediate 6a. Reaction of 2-amino-6-chloropurine (5b) with 3b effected by K2CO3 in dimethylsulfoxide gave compound 6b and a smaller amount of 7-alkylated proauct 7. A similar transformation catalyzed by tetra-n-butylammonium fluoride afforded only intermediate 5b. Acid-catalyzed de-protection (hydrolysis) of 6b and 6a gave the title compounds Ic and Id. The S-enantiomer of Ic was deaminated with adenosine deaminase. Our results argue against the presence of a methyl group-binding site of adenosine deaminase. Compounds Ic and Id exhibited little or no activity in antiviral assays with several DNA and RNA viruses. 相似文献
5.
Abstract Treatment of D-xylose (1) with 0.5% methanolic hydrogen chloride under controlled conditions followed by benzoylation and acetolysis afforded crystalline 1-O-acetyl-2, 3, 5-tri-O-benzoyl-α-D-xylofuranose (4) in good yield. Coupling of 4 with 2, 4-bis-trimethylsilyl derivatives of 5-alkyluracils (methyl, ethyl, propyl and butyl) (5a-5d), 5-fluorouracil (5e) and uracil (5f) in acetonitrile in the presence of stannic chloride gave 1-(2,3,5-tri-O-benzoyl-β-D-xylofuranosyl)-nucleosides (6a-6f). Saponification of 6 with sodium methoxide afforded 1-β-D-xylofuranosyl-5-substituted uracils (7a-7f). Condensation of 4 with free adenine in similar fashion and deblocking gave carcinostatic 9-β-D-xylofuranosyladenine (7g). 相似文献
6.
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
7.
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
8.
Yogesh S. Sanghvi Krishna G. Upadhya N. Kent Dalley Roland K. Robins Ganapathi R. Revankar 《Nucleosides, nucleotides & nucleic acids》2013,32(4):737-759
Abstract Several 4-substituted-1-β-D-ribofuranosyl-3-hydroxypyrazoles were prepared as structural analogs of pyrazofurin. Glycosylation of the TMS derivative of ethyl 3(5)-hydroxypyrazole-4-carboxylate (3) with 1-0-acetyl-2,3,5-tri-0-benzoyl-D-ribofuranose in the presence of TMS-triflate gave predominantly ethyl 3-hydroxy-1-(2,3,5-tri-0-benzoyl-β-D-ribofuranosyl)pyrazole-4-carboxylate (4a), which on subsequent ammonolysis furnished 3-hydroxy-1-β-D-ribofuranosylpyrazole-4-carboxamide (5). Benzylation of 4a with benzyl bromide and further ammonolysis gave 3-benzyloxy-1-β-D-ribofuranosylpyrazole-4-carboxamide (8a). Catalytic (Pd/C) hydrogenation of 8a afforded yet another high yield route to 5. Saponification of the ester function of ethyl 3-benzyloxy-1-β-D-ribofuranosylpyrazole-4-carboxylate (7b) gave the corresponding 4-carboxylic acid (6a). Phosphorylation of 8a and subsequent debenzylation of the intermediate 11a gave 3-hydroxy-1-β-D-ribofuranosylpyrazole-4-carboxamide 5′-phosphate (11b). Dehydration of 3-benzyloxy-1-(2,3,5-tri-0-acetyl-β-D-ribofuranosyl)pyrazole-4-carboxamide (8b) with POCl3 provided the corresponding 4-carbonitrile derivative (10a), which on debenzylation with Cl3SiI gave 3-hydroxy-1-(2,3,5-tri-0-acetyl-β-D-ribofuranosyl)pyrazole-4-carbonitrile (13). Reaction of 13 with H2S/pyridine and subsequent deacetylation gave 3-hydroxy-1-β-D-ribofuranosylpyrazole-4-thiocarboxamide (12b). Similarly, treatment of 13 with NH2OH afforded 3-hydroxy-1-β-D-ribofuranosylpyrazole-4-carboxamidoxime (14a), which on catalytic (Pd/C) hydrogenation gave the corresponding 4-carboxamidine derivative (14b). The structural assignment of these pyrazole ribonucleosides was made by single-crystal X-ray analysis of 6a. None of these compounds exhibited any significant antitumor or antiviral activity in cell culture. 相似文献
9.
Naeem B. Hanna Krishna G. Upadhya Charles R. Petrie Roland K. Robins Ganapathi R. Revankar 《Nucleosides, nucleotides & nucleic acids》2013,32(4):343-362
Abstract The synthesis of several 5′-substituted derivatives of ribavirin (1) and tiazofurin (3) are described. Direct acylation of 1 with the appropriate acyl chloride in pyridine-DMF gave the corresponding 5′-O-acyl derivatives (4a-h). Tosylation of the 2′, 3′-O-isopropylidene-ribavirin (6) and tiazofurin (11) with p-toluenesulfonyl chloride gave the respective 5′-O-p-tolylsulfonyl derivatives (7a and 12a), which were converted to 5′-azido-5′-deoxy derivatives (7b and 12b) by reacting with sodium/lithium azide. Deisopropylidenation of 7b and 12b, followed by catalytic hydrogenation afforded 1-(5-amino-5-deoxy-β-D)-ribofuranosyl)-1, 2, 4-triazole-3-carboxamide (10b) and 2 - (5 -amino- 5-deoxy- β-D-ribofuranosyl) thiazole-4-carboxamide (16), respectively. Treatment of 6 with phthalimide in the presence of triphenylphosphine and diethyl azodicarboxylate furnished the corresponding 5′-deoxy-5′-phthaloylamino derivative (9). Reaction of 9 with n-butylamine and subsequent deisopropylidenation provided yet another route to 10b. Selective 5′-thioacetylation of 6 and 11 with thiolacetic acid, followed by saponification and deisopropylidenation afforded 5′-deoxy-5′-thio derivatives of 1-β-D-ribofuranosyl-1, 2, 4-triazole-3-carboxamide (8a) and 2-β-D-ribofuranosylthiazole-4-carboxamide (15), respectively. 相似文献
10.
Jun-ichi Asakura 《Nucleosides, nucleotides & nucleic acids》2013,32(7):701-711
Abstract Treatment of poly-acetyl or -benzoyl protected ribonucleosides (1a-i) and 2′-deoxyribonucleosides (3a-d) with metal carbonates such as NaHCO3 or Na2CO3 in MeOH gave the corresponding deacylated free ribomucleosides (2a-d and 4a-b) in excellent high yields. 相似文献
11.
Abstract Phase-transfer catalysis of pyrrolo[2,3-d]pyrimidine 4a with the halogenose 5 yields the anomers 6a and 7a. Deprotection with boron trichloride gives the chloro nucleosides 6b and 7b, which are converted into the potential anticytokinin 2 and its α-anomer 3. 相似文献
12.
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
13.
Abstract Isopentenylation of 7-deazaadenine results in the formation of 7-deazatriacanthine (2a) and its corresponding isomer 5a. Chromatographic separation was difficult, but after Dimroth rearrangement of 5a into the exocyclic compound 3a, 7-deazatricanthine could be isolated. Similiar to its parent purine compound, 3a cyclizes in the presence of strong acid to give the tricyclic system 4. NMR data reveal that 7-deazatriacanthine exists as the amino tautomer 2a. Protonation of N-1 alkyl-ated 7-deazaadenine occurs at N-7 to give compound 6 which exhibits restricted rotation of the amino group. The rotational barrier was determined from temperature dependent proton NMR spectra and found to be about 70 kJmol?1. 相似文献
14.
Julia Castro-pichel Ma. Teresa García-López Rosario Herranz Concepción Pérez 《Nucleosides, nucleotides & nucleic acids》2013,32(7):985-1000
Abstract 5′-O-[N-(Aminoacyl)sulfamoyl]-uridines and -thymidines 4a-12a and 4b-12b have been synthesized and tested against Herpes Simplex virus type 2 (HSV-2) and as cytostatics. Condensation of 2′,3′-O-isopropylidene-5′-O-sulfamoyluridine and 3′-O-acetyl-5′-O-sulfamoylthymidine with the N-hydroxysuccinimide esters of Boc-L-Ser(Bzl), (2R, 3S)-3-benzyloxycarbonylamino-2-hydroxy-4-phenylbuta-noic acid [(2R, 3S-N-Z-AHPBA], (2R, 3S) and (2S, 3R)-N-Boc-AHPBA gave 4a,b-7a,b, which after removal of the protecting groups provided 1Oa,b-12a,b. A study of the selective removal of the O-Bzl protecting group from the L-Ser derivatives 4a,b, without hydrogenation of the pyrimidine ring, has been carried out. Only the fully protected uridine derivatives 4a-7a did exhibit high anti-HSV-2 activity, and none of the synthesized compounds showed significant cytostatic activity against HeLa cells cultures. 相似文献
15.
Abstract The oxidation of 8,2′-S-anhydroadenosine (1a) has been investigated. The major product from the oxidation of 1a using 1-chlorobenzotriazole was the R-sulfoxide. The oxidation of 3′,5′-di-O-acetyl-8,2′-S-anhydroadenosine (1b) gave predominately the S-sulfoxide. These sulfoxides were found to be very succeptible to nucleophilic attack at C-8. 相似文献
16.
SUMMARY The presence of sediment at concentrations of 0,2% by mass in water samples significantly lowered the amount of chlorophyll a that could be measured. Two types of sediment differed in their ability to lower the chlorophyll a concentration. The chemically more active sediment had a marked depressive effect on the chlorophyll a concentration and the relationship between chlorophyll a and cell numbers in the samples was non-linear. It is recommended that the use of chlorophyll a as an indicator of biomass in water containing sediment should be approached with care. 相似文献
17.
F. Seela H. Driller K. Kaiser H. Rosemeyer H. Steker 《Nucleosides, nucleotides & nucleic acids》2013,32(5-6):789-792
Abstract The synthesis of pyrazolo[3,4-d]pyrimidine 2′-deoxyribo-nucleosides with various substituents at C-4 and C-6 (1 4) is described employing either liquid-liquid or solid-liquid phase-transfer glycosylation. From 1a (Z8C7Ad) and 2b (Z8C7Gd) the phosphoramidites 12a, b and 15a, b were synthesized. They were used in automated solid-phase synthesis resulting in the oligonucleotides 16 - 25. Deoxygenation (3′-OH) of 1a and 2b yielded pyrazolo[3,4-d]-pyrimidine 2′,3′-dideoxynucleosides isosteric to ddA, ddG, and ddI. 相似文献
18.
Abstract Crystal structure analyses of uridine-6-thiocarboxamide (I) and 6-cyanouridine (II) show that both structures adopt a syn conformation about the glycosyl bond. The conformation of I is similar to that of orotidine (III). The furanose ring conformation of I is C4′-exo, unusual for syn conformers, and is C3′-endo in II. These results have a bearing on the inhibition of orotidylate decarboxylase by the 5′-phosphate of I. 相似文献
19.
Yogesh S. Sanghvi Naeem B. Hanna Steven B. Larson Roland K. Robins Ganapathi R. Revankar 《Nucleosides, nucleotides & nucleic acids》2013,32(4):761-774
Abstract A synthesis of 1-(2,3-dideoxy-β-D-ribofuranosyl)-1,2,4-triazole-3-carboxamide (2′,3′-dideoxyribavirin, ddR) is described. Glycosylation of the sodium salt of 1,2,4-triazole-3-carbonitrile (5) with 1-chloro-2-deoxy-3,5-di-0-p-toluoyl-α-D-erythro-pentofuranose (1) gave exclusively the corresponding N-1 glycosyl derivative with β-anomeric configuration (6), which on ammonolysis provided a convenient synthesis of 2′-deoxyribavirin (7). Similar glycosylation of the sodium salt of methyl 1,2,4-triazole-3-carboxylate (2) with 1 gave a mixture of corresponding N-1 and N-2 glycosyl derivatives (3) and (4), respectively. Ammonolysis of 3 furnished yet another route to 7. A four-step deoxygenation procedure using imidazolylthiocarbonylation of the 3′-hydroxy group of 5′-0-toluoyl derivative (9a) gave ddR (11). The structure of 11 was proven by single crystal X-ray studies. In a preliminary in vitro study ddR was found to be inactive against HIV retrovirus. 相似文献
20.
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