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1.
Manuel Alonso-Lopez Manuel Bernabe Alfonso Fernandez-Mayoralas Jesus Jimenez-Barbero Manuel Martin-Lomas Soledad Penades 《Carbohydrate research》1986,150(1):103-109
The reaction of benzyl 2,6,6′-tri-O-benzyl-3′,4′-O-isopropylidene-β-lactoside with 1,11-ditosyloxy-3,6,9-trioxaundecane gave benzyl 2,6,6′-tri-O-benzyl-3′,4′-O-isopropylidene-3,2′-O--(3,6,9-trioxaundecane-1,11-diyl)-β-lactoside (2, 47%). Acid hydrolysis of 2 and condensation of the product with 1,14-ditosyloxy-3,6,9,12-tetra-oxatetradecane afforded benzyl 2,6,6′-tri-O-benzyl-3′,4′-O-(3,6,9,12-tetraoxa-tetradecane-1,14-diyl)-3,2′-O-(3,6,9-trioxaundecane-1,11-diyl)-β-lactoside (29%). Similarly, the reaction of benzyl 2,6,2′,4′,6′-penta-O-benzyl-β-lactoside with Ts[OCH2CH2]4OTs gave benzyl 2,6,2′,4′,6′-penta-O-benzyl-3,3′-O-(3,6,9-trioxaundecane-1,11-diyl)-β-lactoside (78%). 1H-N.m.r. spectroscopy has been used to study the formation of host-guest complexes with some of these macrocyclic compounds and benzyl ammonium thiocyanate. 相似文献
2.
3.
Akira Matsuda Krzysztof Pankiewicz Bonita K. Marcus Kyoichi.A. Watanabe Jack J. Fox 《Carbohydrate research》1982,100(1):297-302
The first chemical synthesis of 3-methyl-ψ-uridine (5) and its 2′-deoxy analogue (9) has been achieved. ψ-Uridine was trimethylsilylated and the crude product was treated with acetyl chloride, to give the 1-acetyl derivative (3). Crude 3 was methylated with dimethoxymethyldimethylamine and then saponified, to give crystalline 5 in 82% overall yield. Treatment of 5 with 1,3-dichloro-1,1,3,3-tetraiso-propyldisiloxane afforded the 3′,5′-protected product, which was converted into the 2′-O-[(imidazol-1-yl)thiocarbonyl] derivative 7. Reduction of 7 with tributyltin hydride followed by deblocking of the product gave crystalline 2′-deoxy-3-methyl-ψ-uridine (9) in 35% yield from 5. 相似文献
4.
Minowa N Akiyama Y Hiraiwa Y Maebashi K Usui T Ikeda D 《Bioorganic & medicinal chemistry letters》2006,16(24):6351-6354
Synthesis and activity of derivatives at the O5 or O6 positions of 1-N-((S)-4-amino-2-hydroxybutyryl)-3′,4′-dideoxyneamine, which is the neamine moiety of arbekacin, were reported. Among these results, the 5-O-aminoethylaminocarbonyl derivative showed effective activity against Staphylococcus aureus expressing a bifunctional aminoglycoside-modifying enzyme AAC(6′)-APH(2″). 相似文献
5.
Chalconoid and stilbenoid glycosides from Guibourtia tessmanii 总被引:2,自引:0,他引:2
Fuendjiep V Wandji J Tillequin F Mulholland DA Budzikiewicz H Fomum ZT Nyemba AM Koch M 《Phytochemistry》2002,60(8):1091-806
Phytochemical studies on the stem bark of Guibourtia tessmanii yielded a dihydrochalcone glucoside, 2′,4-dihydroxy-4′-methoxy-6′-O-β-glucopyranoside dihydrochalcone and a new stilbene glycoside, 3,5-dimethoxy-4′-O-(β-rhamnopyranosyl-(1→6)-β- glucopyranoside) stilbene besides the known pterostilbene. Their structures were established on the basis of one and two dimensional NMR spectroscopic techniques, FABMS and chemical evidence. 相似文献
6.
Ruben G. G. Leenders Hans W. ScheerenPieter H. J. Houba Epie Boven Hidde J. Haisma 《Bioorganic & medicinal chemistry letters》1995,5(24):2975-2980
The synthesis, antiproliferative effect and enzymatic hydrolysis of daunomycin-3′-N- and -4′-O-phosphate and -sulfate derivatives and of daunomycin-3′-N-CO-β-glucuronide and -β-glucoside, designed to be prodrugs in ADEPT are described. The phosphate derivatives were almost as toxic as the parent drug whereas the sulfates were not hydrolyzed by aryl sulfatases. Glucuronyl and glucosyl prodrugs were found to be useful for application in ADEPT. 相似文献
7.
Stephen J. Bloor 《Phytochemistry》1999,50(8):1242-1399
The blue colour of the petals of the blue marguerite daisy, Felicia amelloides, has been found to arise from copigmentation between a novel malonylated delphinidin triglycoside, delphinidin 3-O-neohesperidoside 7-O- (6-O-malonyl-glucoside), and a new flavone C-glycoside, swertisin 2″-O-rhamnoside-4′-O-glucoside. Recombination, in vitro, of these two petal components at pH 6 recreates the blue petal colour. 相似文献
8.
Javier Ibarrondo Aida Marino Gilles Guillon Miguel Trueba JosMaría Macarulla 《Cellular signalling》1991,3(6):577-585
The mechanisms whereby adenosine-5−triphosphate (ATP)_regulated the inositol phospholipid-signalling system were studied in rat hepatocytes. Intact hepatocytes respond to extracellular ATP, adenosine-5′-O-(3-thiotriphosphate) (ATPγS), ADP and weakly to guanosine-5′-triphosphate (GTP), but not to other purine nucleotides (GDP or AMP). This is consistent with the ideal that a P2 purinergic receptor is coupled to the phosphatidylinositol metabolism in these cells. Partially purified plasma membranes prepared from myo-[3H]inositol prelabelled hepatocytes exhibit a phosphatidylinositol-4,5-bisphosphate phospholipase C activity sensitive to ATP, ATPγS and guanosine-5′-O-(3-thiotriphosphate) (GTPγS). Moreover the GTPγS effect of greatly enhanced by ATP and ATPγS. These potentiating effects differ according to the adenylnucleotide considered. ATP produces (1) an increase in the GTPγS-PLC sensitivity, (2) a potentiation of the phospholipase C (PLC) response induced by maximal dose of GTPγS, and (3) an increase in the inositol lipids pools. At variance, ATPγS, a nonhydrolysable analogue of ATP, only increases the PLC-sensitivity towards GTPγS. These results may signify that ATP stimulates inositol phosphate accumulation via at least two distinct mechanisms (i) a direct activation of a P2 purinergic receptor coupled to a PLC via a GTP binding protein and (ii) a stimulation of the phosphatidylinositol (PI) and phosphatidyinositol-4-phosphate (PIP) kinases which increased the pool of phospholipase C substrates. 相似文献
9.
Andr s Lipt k Lajos Szab J nos Ker kgy rt J nos Harangi P l N n si
Helmut Duddeck
《Carbohydrate research》1986,150(1):187-197The title tetrasacharide having the structure 3-O-Me-β-
-Xylp-(1→4)--
-Rhap-(1→4)--
-Rhap-(1→2)-
-Rhap was obtained by reaction of the -acetobromo derivative of 4-O-(3-O-methyl-β-
-xylopyranosyl)-
-rhamnopyranose and benzyl 3,4-di-O-benzyl-2-O-(2,3-O-isopropylidene--
-rhamnopyranosyl)--
-rhamnopyranoside, followed by removal of the protecting groups. The synthesised compounds were characterised on the basis of n.m.r. data. 相似文献
10.
Addition of iodine and methanol to N6,N6-dibenzoyl-9(2,3-O-carbonyl-5-deoxy-β-d-erythro-pent-4-enofuranosyl)adenine (4) selectively gives N6,N6-dibenzoyl-2′,3′-O-carbonyl-5′-deoxy-5′-iodo-4′-methoxyadenosine (5). Compound 5 can be converted into 4′-methoxyadenosine via hydrolysis of the carbonate followed by benzoylation, displacement of the 5′-iodo function by benzoate ion, and hydrolysis with ammonia. Configurational assignments are based upon comparisons of 1H- and 13C-n.m.r. spectra with those of previously characterised analogues in the uracil series and by borate electrophoresis. Intermediates in the above scheme have also been converted into 5′-amino-5′-deoxy-4′-methoxyadenosine, 4′-methoxy-5′-O-sulfamoyladenosine, and ethyl 4′-methoxyadenosine-5′-carboxylate, each of which is a 4′-methoxy analogue of biologically active derivatives of adenosine. 相似文献
11.
I A Mikhailopulo T I Pricota N E Poopeiko G G Sivets E I Kvasyuk T V Sviryaeva L P Savochkina R S Beabealashvilli 《FEBS letters》1989,250(2):139-141
3′-Fluoro-3′-deoxy-uridine, -cytidine, -adenosine and -guanosine have been synthesized by glycosylation of the corresponding silylated bases with 1-O-acetyl-2,5-di-O-benzoyl-3-fluoro-3-deoxy-D-ribofuranose in the presence of Friedel-Crafts catalysts and were converted to the 5′- triphosphates, NTP(3′-F). It was shown that NTP(3′-F) are terminators of RNA synthesis catalyzed by DNA-dependent RNA polymerase from E. coli and may thus serve as tools for DNA sequencing. 相似文献
12.
A. Gilberto Ferreira Joo B. Fernandes Paulo C. Vieira Otto R. Gottlieb Hugo E. Gottlieb 《Phytochemistry》1995,40(6):1723-1728
The seeds of Otoba parvifolia contain three novel compounds apparently derived from homogentisic acid, rel-(1′R,5′R)-2-(1′-farnesyl-5′-hydroxy-2′-oxocyclohex-3′-en-1′-yl)-acetic acid and its acetate as well as rel-(1′R,4′S,5′R)-2-(1′-farnesyl-4′,5′-dihydroxy-2′-oxocyclohexan-1′-yl)-acetic acid δ-lactone. The structure of an additional isolate, previously described as 2-(1′-farnesyl-2′-hydroxy-5′-oxocyclohex-3′-en-1′-yl)-acetic acid γ-lactone was revised to rel-(1′R,5′R)-2-(1′-farnesyl-5′-hydroxy-2′-oxocyclohex-3′-en-1′-yl)-acetic acid δ-lactone. 相似文献
13.
Otilia D. L. Pessoa Telma L. G. De Lemos M rio G. De Carvalho Raimundo Braz-Filho 《Phytochemistry》1995,40(6):1777-1786
Further cordiachromes, rel-10,11β-epoxy-11-ethoxy-8-hydroxy-2-methoxy-8aβ-methyl-5,6,7,8,8a,9,10aβ-octahydro-1,4-anthracendione, 6-formyl-2-methoxy-9-methyl-7,8-dihydro-1,4-phenanthrendione, rel-8,11;9,11-diepoxy-1,4-dihydroxy-2-methoxy-8aβ-methyl-5,6,7,8,8a,9,10,10aβ-octahydro-10-anthracenone, rel-9,11-epoxy-1,4,8-trihydroxy-2-methoxy-8aβ-methyl-5,6,7,8,8a,9,10,10aβ-octahydro-10-anthracenone, rel-2″-methoxy-7″-methyl-1″,4″-naphtalendione-(6″→5)-tetrahydropyran-(2-eq→O→2ax)-tetrahydropyran-(5′→6)- 2-methoxy-7-methyl-1,4-naphthalendione, together with the known, allantoin, sitosterol and 3β-O-d-glucopyranosylsitosterol, have been isolated from Auxemma oncocalyx. Their structures were determined from spectral data, including 2D NMR experiments. 相似文献
14.
María A. Zinni Silvio D. Rodríguez Rodrigo M. Pontiggia Javier M. Montserrat Luis E. Iglesias Adolfo M. Iribarren 《Journal of Molecular Catalysis .B, Enzymatic》2004,29(1-6):129-132
Candida antarctica-B (CAL-B) lipase-catalysed alcoholysis of a set of 3′,5′-di-O-acetyl-2′-deoxynucleosides (1a–e) gave the corresponding 3′-O-acetyl-2′-deoxy-nucleosides (2a–e) in yields ranging from 50 to 96%. The alcohol employed in the biotransformation affected the rate of the enzymatic reaction and the yield of the 3′-O-acetylated product, but in all cases only this regioisomer was formed. The obtained results are in agreement with the regioselectivity displayed by CAL-B lipase in previously reported biotransformations of nucleosides. CAL-B catalysed alcoholysis of 2′,3′,5′-tri-O-acetyl-cytidine and 4-N-acetyl-2′,3′,5′-tri-O-acetylcytidine was also studied, affording with the same regioselectivity the corresponding free 5′-hydroxyl nucleosides. 相似文献
15.
Roberto Pellicciari Gabriele Costantino Maura Marinozzi Antonio Macchiarulo Laura Amori Peter Josef Flor Fabrizio Gasparini Rainer Kuhn Stephan Urwyler 《Bioorganic & medicinal chemistry letters》2001,11(24):3179-3182
Two novel 3′-substituted carboxycylopropylglycines, (2S,1′S,2′S,3′R)-2-(3′-xanthenylmethyl-2′-carboxycyclopropyl)glycine (8a) and (2S,1′S,2′S,3′R)-2-(3′-xanthenylethyl-2′-carboxycyclopropyl)glycine (8b), were synthesized and evaluated as mGluR ligands. Compound 8b showed to be a potent group II antagonist with submicromolar activity. 相似文献
16.
De Souza AM Lopes AG Pizzino CP Fossari RN Miguel NC Cardozo FP Abi-Abib R Fernandes MS Santos DP Caruso-Neves C 《Regulatory peptides》2004,120(1-3):167-175
In the present paper, the modulation of the basolateral membrane (BLM) Na+-ATPase activity of inner cortex from pig kidney by angiotensin II (Ang II) and angiotensin-(1–7) (Ang-(1–7)) was evaluated. Ang II and Ang-(1–7) inhibit the Na+-ATPase activity in a dose-dependent manner (from 10−11 to 10−5 M), with maximal effect obtained at 10−7 M for both peptides. Pharmacological evidences demonstrate that the inhibitory effects of Ang II and Ang-(1–7) are mediated by AT2 receptor: The effect of both polypeptides is completely reversed by 10−8 M PD 123319, a selective AT2 receptor antagonist, but is not affected by either (10−12–10−5 M) losartan or (10−10–10−7 M) A779, selective antagonists for AT1 and AT(1–7) receptors, respectively. The following results suggest that a PTX-insensitive, cholera toxin (CTX)-sensitive G protein/adenosine 3′,5′-cyclic monophosphate (cAMP)/PKA pathway is involved in this process: (1) the inhibitory effect of both peptides is completely reversed by 10−9 M guanosine 5′-O-(2-thiodiphosphate) (GDPβS; an inhibitor of the G protein activity), and mimicked by 10−10 M guanosine 5′-O-(3-thiotriphosphate) (GTPγS; an activator of the G protein activity); (2) the effects of both peptides are mimicked by CTX but are not affected by PTX; (3) Western blot analysis reveals the presence of the Gs protein in the isolated basolateral membrane fraction; (4) (10−10–10−6 M) cAMP has a similar and non-additive effect to Ang II and Ang-(1–7); (5) PKA inhibitory peptide abolishes the effects of Ang II and Ang-(1–7); and (6) both angiotensins stimulate PKA activity. 相似文献
17.
Wei Li Kazuo Koike Yoshihisa Asada Takafumi Yoshikawa Tamotsu Nikaido 《Journal of Molecular Catalysis .B, Enzymatic》2005,35(4-6):117-121
Panax ginseng root and cell cultures were shown to biotransform paeonol (1) into its 2-O-β-d-glucopyranoside (2). P. ginseng root cultures were also able to biotransform paeonol (1) into its 2-O-β-d-xylopyranoside (3), 2-O-β-d-glucopyranosyl(1 → 6)-β-d-glucopyranoside (4) and 2-O-β-d-xylopyranosyl(1 → 6)-β-d-glucopyranoside (5), and its demethylated derivate, 2′,4′-dihydroxyacetophenone (6). Compounds 3 and 4 are new glycosides. It is the first example that the administrated compound was converted into its xylopyranoside by plant biotransformation. 相似文献
18.
Decendit A Waffo-Teguo P Richard T Krisa S Vercauteren J Monti JP Deffieux G Mérillon JM 《Phytochemistry》2002,60(8):795-798
Suspension cultures of Vitis vinifera were found to produce catechins and stilbenes. When cells were grown in a medium inducing polyphenol synthesis, (−)-epicatechin-3-O-gallate, dimeric procyanidin B-2 3′-O-gallate and two resveratrol diglucosides were isolated, together with a new natural compound that was identified as cis-resveratrol-3,4′-O-β-diglucoside by spectroscopical methods. 相似文献
19.
L'homme R Brouwers E Al-Maharik N Lapcík O Hampl R Mikola H Wähälä K Adlercreutz H 《The Journal of steroid biochemistry and molecular biology》2002,81(4-5):353-361
We present a method for the determination of the phytoestrogen metabolite O-desmethylangolensin (O-DMA) in plasma (serum) and in urine. O-DMA is a metabolite of daidzein, which occurs in soybeans. It has been suggested that isoflavones may afford protection against breast and prostate cancer and therefore, also the metabolites are of interest. The method is based on time-resolved fluoroimmunoassay (TR–FIA) using a europium chelate as a label. After the synthesis of 4′′-O-carboxymethyl-O-DMA, this compound is coupled to bovine serum albumin, and then used as antigen in immunization of rabbits. The tracers with the europium chelate are synthesized using the same 4′′-O-derivative of the -methyldeoxybenzoin. After enzymatic hydrolysis and ether extraction the immunoassay is carried out by time resolved fluoroimmunoassay (TR–FIA). Cross-reactivity was tested with angolensin, dihydrogenistein, dihydrodaidzein, equol, 6′-OH-angolensin, trans-4-OH-equol, 6′-OH-O-DMA, cis-4-OH-equol and 5-OH-equol. The antiserum cross-reacted only with angolensin. This cross-reactivity seems not to influence the results, which were highly specific. Plasma samples are hydrolyzed and extracted. Urine samples are analyzed directly after hydrolysis without extraction. The correlation coefficient between the plasma TR–FIA results and the GC–MS results was high; r value was 0.985. The correlation coefficient between the urine TR–FIA results and the GC–MS results was high over the entire range of concentrations (0–1500 nmol/l); r value was 0.976, but lower in the low concentration range (0–100 nmol/l), i.e. value was 0.631. The intra-assay coefficients of variation (CVs) for plasma O-DMA concentrations and for urine O-DMA concentrations at three different concentrations varied 2.8–7.7 and 3.0–6.0%, respectively and the inter-assay CVs varied 3.8–8.9 and 4.4–6.6%, respectively. The working range of the plasma and urine O-DMA assays was 0.5–512 nmol/l. 相似文献
20.
Three main saponins were isolated from the seeds of Albizzia lucida. Their structures were established by spectral analyses and chemical and enzymatic transformations as 3-O-[β-
-xylopyranosyl(1→2)--
-arabinopyranosyl (1→6)] [β-
-glucopyranosyl (1→2)] β-
-glucopyranosyl echinocystic acid; 3-O-[-
-arabinopyranosyl (1→6)][β-
-glucopyranosyl (1→2)]-β-
-glucopyranosyl echinocystic acid and 3-O-[β-
-xylopyranosyl (1→2)-β-
-fucopyranosyl (1→6)-2-acetamido-2-deoxy-β-
-glucopyranosyl echinocystic acid, characterized as its methyl ester. 相似文献