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  • 1980-1984  (25)
  • 1
    Electronic Resource
    Electronic Resource
    Adaptive Use of N2-Dimethyl-Substituted Pterins by Cultures of Crithidia fasciculata (1981)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 28 (1981), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The compound 6-(L-erythro-1,2′,3′-trihydroxypropyl)pterin, at a concentration of 50 pg/ml (“L-erythro-neopteria”), supports half-maximal growth of Crithidia fasciculata; biopterin at a concentration of 30 pg/ml is shown to yield similar growth. N2-dimethyl-6-(L-erythro-1′,2′,3′-trihydroxypropyl)pterin (A) was inactive even at 100 ng/ml. Synergism was observed with the N2-dimethylamino derivative (A) in the presence of suboptimal biopterin, its activity then being of the order of L-erythro-neopterin. In contrast, the stereoisomeric N2-dimethyl-6-(D-erythro-1′,2′,3′-trihydroxypropyl)pterin (“dimethyl-D-erythro-neopterin”) and its 3′-mono-phosphate only slightly enhanced growth under similar conditions but both threo-isomers had no supplementary activity. Biopterin-induced growth was slowed by 6-(D-erythro1′,2′,3′-trihydroxypropyl)pterin (D-neopterin); the threo-isomers had no such effect. An adaptive demethylation capacity by growing cultures and competition of biopterin uptake by D-neopterin seems likely. The report of the occurrence in Euglena of N2-dimethyl-6-(L-threo-1′,2′,3′-trihydroxypropyl)pterin and its 3′-mono-phosphate adds further interest to our observations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.1981.tb02865.x
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  • 2
    Electronic Resource
    Electronic Resource
    Pteridine, LXIX. Synthese und Reaktivität des 2,4-Diamino-6-(hydroxymethyl)-pteridins (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1514-1523 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pteridines, LXIX. Synthesis and Reactivity of 2,4-Diamino-6-(hydroxymethyl)pteridineCondensation of 2,4,5,6-tetraaminopyrimidine (2) with 1,3-dihydroxyacetone in the presence of gaseous oxygen, rather than air, resulted in 2,4-diamino-6-(hydroxymethyl)pteridine (3) virtually uncontaminated with 2,4-diamino-6-methylpteridine (4). Acetylation of 3 led to 6-acetoxymethyl-2,4-bis(acetylamino)pteridine (5) which turned out to be very labile forming various di- and monoacetyl derivatives (6, 7, 9, 10) on mild hydrolytic conditions. Their structures are proven by physical-chemical means. Silylation of 3 to the tris(trimethylsilyl) derivative 11 followed by treatment with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (12) and 1,2,3,4,6-penta-O-acetyl-β-D-glucopyranose (15), respectively, in the presence of boron trifluoride, led to selective formation of the corresponding acylated 2,4-diamino-6-pteridinyl O-glycosides 13 and 15, respectively. Deacylations of these afforded the free O-glycosides 14 and 17 which have been characterized by UV-and NMR spectra as well as pKa measurements.
    Notes: Die Kondensation von 2,4,5,6-Tetraaminopyrimidin (2) mit 1,3-Dihydroxyaceton in Gegenwart von Sauerstoff anstelle von Luft führt in guter Ausbeute zu 2,4-Diamino-6-(hydroxymethyl)pteridin (3) ohne nennenswerte Bildung von 2,4-Diamino-6-methylpteridin (4). Acetylierung von 3 liefert das 6-Acetoxymethyl-2,4-bis(acetylamino)pteridin (5), das sich als erstaunlich labile Verbindung erwies und leicht unter hydrolysierenden Bedingungen in verschiedene Di- und Monoacetyl-Derivate (6, 7, 9, 10) übergeht. Ihre Konstitutionen werden durch physikalisch-chemische Untersuchungen gesichert. Durch Silylierung von 3 zum 6-Trimethylsiloxymethyl-2,4-bis(trimethylsilyl-amino)pteridin (11) und dessen Glycosidierung mit 1-O-Acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (12) bzw. 1,2,3,4,6-Penta-O-acetyl-β-D-glucopyranose (15) unter BF3-Katalyse entstehen in selektiver Reaktion die acylierten 2,4-Diamino-6-pteridinylmethyl-O-glycoside 13 bzw. 16. Entacylierung ergibt die freien O-Glycoside 14 und 17, die durch UV- und NMR-Spektren sowie pKa-Messungen charakterisiert werden.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130431
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  • 3
    Electronic Resource
    Electronic Resource
    Nucleoside, XXXII. Über die Ribosidierung des 7-Oxo-7,8-dihydrolumazins und seines 6-Methyl- und 6-Phenyl-Derivates (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1524-1534 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nucleosides, XXXII. Ribosylations of 7-Oxo-7,8-dihydrolumazine and its 6-Methyl- and 6-Phenyl DerivativesRibosylation reactions of 7-oxo-7,8-dihydrolumazine (1) and its 6-methyl- (2) and 6-phenyl derivative, respectively, are described. Treatment of the trimethylsilyl derivatives 6 - 8 with 2,3,5-tri-O-benzoyl-1-bromo-D-ribofuranose (9) in the presence of Hg-salts leads to mixtures of the corresponding N-1-mono- (11 - 13) an N-1,N-3-diribosides (17 - 19), whereas the analogous reaction with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (10) and SnCl4 gave N-3-nucleosides (23 - 25). N-8-Substitution has not been observed. On debenzoylations the free nucleosides 14 - 16, 22, and 26 - 28 are formed. The structures of the newly synthesized compounds have been established by UV- and NMR spectra as well as pK determinations.
    Notes: 7-Oxo-7,8-dihydrolumazin (1), sein 6-Methyl-(2) und 6-Phenyl-Derivat (3) werden in Form ihrer Trimethylsilyl-Derivate 6 - 8 Ribosidierungsreaktionen unterworfen. 2,3,5-Tri-O-benzoyl-1-brom-D-ribofuranose (9) führt unter Hg-Salz-Katalyse zu den entsprechenden N-1-Mono-(11 - 13) und N-1,N-3-Diribosiden (17 - 19), während mit 1-O-Acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (10) und SnCl4 die N-3-Nucleoside 23 - 25 gebildet werden. Eine N-8-Substitution wird nicht beobachtet. Entbenzoylierungen führen zu den freien Nucleosiden 14 - 16, 22 und 26 - 28. Die Verbindungen werden durch UV- und NMR-Spektren sowie pK-Werte charakterisiert.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130432
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  • 4
    Electronic Resource
    Electronic Resource
    Nucleoside, XXXIII. Über die Synthese des 7-Oxo-8-β-D-ribofuranosyl-7,8-dihydro-lumazins und seines 6-Methyl-Derivates (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1535-1548 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nucleosides, XXXIII. Synthesis of 7-Oxo-8-β-D-ribofuranosyl-7,8-dihydrolumazine and its 6-Methyl DerivativeThe synthesis of 7-oxo-8-β-D-ribofuranosyl-7,8-dihydrolumazine (26) and its 6-methyl derivative (28) has been achieved by a ribosylation reaction of 2,4-bis(benzyloxy)- (18) and 2,4-bis(benzyl-oxy)-6-methyl-7-oxo-7,8-dihydropteridine (19), respectively, under Hg(CN)2-catalysis. 7-O-Ribosides are formed in the first step of the reaction and undergo 7-O→N-8-rearrangements (29, 30) as well as intermolecular transglycosidations with formation of N-1,7-O-di- (23, 24) and N-1,N-3,7-O-triribosides (32), respectively, on prolonged heating in the presence of Hg-salts. The reaction mixtures have been separated chromatographically and the structures of the various components proven by spectrophotometrical and chemical means. The blocking groups in 2,4-bis(benzyloxy)-7-oxo-8-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-7,8-dihydropteridine (29) and its 6-methyl derivative (30), respectively, have been cleaved by catalytic hydrogenation on Pd/C to 25 and 27 and by ammonia in methanol to 26 and 28. Attempts for the synthesis of 26 starting from 6-amino-2,4-dimethoxy-5-nitropyrimidine (3) are also described, leading however only to the formation of 8-D-ribityl-(12) and 8-β-D-ribofuranosyl-2,4-dimethoxy-7-oxo-7,8-dihydropteridine (14), respectively.
    Notes: Die Synthese von 7-Oxo-8-β-D-ribofuranosyl-7,8-dihydrolumazin (26) und seinem 6-Methyl-Derivat (28) kann durch Ribosidierung von 2,4-Bis(benzyloxy)-(18) bzw. 2,4-Bis(benzyloxy)-6-methyl-7-oxo-7,8-dihydropteridin (19) unter Hg(CN)2-Katalyse realisiert werden. Es entstehen zunächst 7-O-Riboside (20, 21), die bei längerem Kochen in Gegenwart von Hg-Salzen sowohl einer 7-O→N-8-Umglycosidierung (29, 30) als auch einer intermolekularen Transglycosidierung unter Bildung von N-1,7-O-Di-(23, 24) und N-1,N-3,O-7-Triribosiden (32) unterliegen. Die Substanzgemische werden chromatographisch in die einzelnen Komponenten zerlegt und ihre Konstitutionen auf spektroskopischem und chemischem Wege ermittelt. Die Schutzgruppenabspaltung im 2,4-Bis(benzyloxy)-7-oxo-8-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-7,8-dihydropteridin (29) und seinem 6-Methyl-Derivat (30) erfolgte auf katalytischem Wege mit Pd/C und anschließender Ammoniak-Behandlung zu 25 und 27 bzw. 26 und 28. Es wird ferner über Syntheseversuche von 26, ausgehend vom 6-Amino-2,4-dimethoxy-5-nitropyrimidin (3), berichtet, die jedoch lediglich zu 8-D-Ribityl-(12) bzw. 8-β-D-Ribofuranosyl-2,4-dimethoxy-7-oxo-7,8-dihydropteridin (14) führten.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130433
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  • 5
    Electronic Resource
    Electronic Resource
    Nucleoside, XXXIV1) Über die Ribosidierung des 5,6-Dihydro-6-oxolumazins und seines 1,3-Dimethyl-Derivates (1981)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 114 (1981), S. 699-706 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nucleosides, XXXIV1) Ribosylations of 5,6-Dihydro-6-oxolumazine and its 1,3-Dimethyl Derivative5,6-Dihydro-6-oxolumazine (1) and its 1,3-dimethyl derivative (2) have been ribosylated as their trimethylsilyl derivatives 9 and 3 with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (8) under BF3-etherate catalysis. 2 leads to an anomeric mixture of 1,3-dimethyl-6-(2,3,5-tri-O-benzoyl-α-and -β-D-ribofuranosyloxy)lumazine (4,5) which have been separated chromatographically. Starting from 1 5,6-dihydro-6-oxo-1,3-bis(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)lumazine (10) was the main reaction product besides small amounts of the corresponding anomeric 6-O-α- and-β-triribosides 12 and 13.
    Notes: 5,6-Dihydro-6-oxolumazin (1) und sein 1,3-Dimethyl-Derivat (2) werden als Trimethylsilyl-Derivate 9 bzw. 3 mit 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (8) unter BF3-Etherat-Katalyse ribosidiert. 2 ergibt ein Anomerengemisch aus 1,3-Dimethyl-6(2,3,5-tri-O-benzoyl-α-und-β-D-ribofuranosyloxy)lumazin (4, 5), das chromatographisch getrennt wird. Aus 1 wird als Hauptprodukt 5,6-Dihydro-6-oxo-1,3-bis(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)lumazin (10) erhalten neben kleinen Mengen der entsprechenden anomeren 6-O-α- und -β-Tririboside 12 und 13.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19811140228
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  • 6
    Electronic Resource
    Electronic Resource
    Nucleotide. XVXIV. Mitt. s. [1].. Synthese und Eigenschaften von 2′-O-t-Butyldimethylsilyl-5′-O-monomethoxytritylribonucleosid-3′-phosphotriestern, Ausgangssubstanzen für Oligonucleotid-Synthesen (1981)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 64 (1981), S. 1704-1716 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nucleotides. XV. Synthesis and Properties of 2′O-t-Butyldimethylsilyl-5′-O-monomethoxytritylribonucleoside-3′-phosphotriesters, Starting Materials for Oligonucleotide SynthesesThe syntheses of two types of fully blocked ribonucleoside 3′-phosphotriesters 6-14 have been achieved in excellent yields from 2′-O-t-butyldimethylsilyl-5′-O-monomethoxytrityl-ribonucleosides 1-5 by phosphorylation with 2-chloro- and 2,5-dichlorophenylphosphorodichloridate respectively and subsequent treatment by cyanoethanol to 6, 8, 10, 12 and 14 and by p-nitrophenylethanol to 7, 9, 11 and 13. These phosphotriesters are valuable starting materials for oligonucleotide syntheses due to the fact that the corresponding phosphotriesters 15-23 with free HO—C(5′) could be obtained by detritylation and the 3′-phosphodiester triethylammonium salts 24-32 by deblocking of the cyanoethyl and the 2,5-dichlorophenyl group respectively. All newly synthesized compounds have been characterized by UV.-and NMR.-spectra as well as C, H, N elementary analyses.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19810640548
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  • 7
    Electronic Resource
    Electronic Resource
    Nucleotide. XIVTeil XIII: [1].. Substituierte β-Phenyläthyl-Gruppen. Neue Schutzgruppen für Oligonucleotid-Synthesen nach dem Phosphorsäuretriester-VerfahrenHerrn Prof. Dr. Conrad Hans Eugster in Verbundenheit zum 60. Geburtstag gewidmet (1981)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 64 (1981), S. 1688-1703 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: XIV. Substituted β-Phenyl-ethyl Groups. New Blocking Groups for Oligonucleotide Syntheses by the Phosphotriester ApproachVarious o- and p-substituted β-phenylethanols (2-10) have been synthesized and investigated as blocking groups in the phosphotriester approach. A large number of 5′-O-tritylated thymidine-3′-phosphotriesters (13-36) with two different phosphate protecting groups have been prepared, characterized, and studied according to their chemical stability and usefullness for oligonucleotide syntheses. The combination of a 5′-O-monomethoxytrityl- and a 3′-(2,5-dichlorophenyl, p-nitrophenylethyl)-phosphate function as in 18 turned out to possess optimal properties as a monomeric nucleotide building block due to the fact that these blocking groups can be quantitatively and selectively be removed without harming each other by trifluoroacetic acid in chloroform to 41, by oximate to 42, and by DBU to 43. The base-catalyzed removal of the monosubstituted phenylethyl groups by DBU or DBN respectively as well as the disubstituted phenylethyl groups by triethylamine in aprotic solvents is a β-elimination process leading to phosphodiesters without attack on the P-center.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19810640547
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  • 8
    Electronic Resource
    Electronic Resource
    Nucleotide, XVIITeil XVI: [1].. Synthese von homogenen Adenosyl-3′,5′-Oligomeren nach dem Phosphotriester-VerfahrenAus den Dissertation von D.F. [2] und E.U. [3]. (1983)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 66 (1983), S. 2018-2030 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nucleotides, XVII. Synthesis of Homogeneous Adenosyl-3′,5′-oligomers by the Phosphotriester MethodThe chemical synthesis of the fully protected trimer 12, the tetramers 11 and 23 as well as the pentamer 14 was achieved in preparative scales starting from the fully blocked adenosine-3′-phosphotriesters 1, 2, and N6-benzoyl-2′,3′-bis-O-(tert-butyldimethylsilyl)adenosine (6). All intermediates and end products have been isolated, purified and characterized by elemental analyses, UV, and CD spectra. Deprotection of the various blocking groups proceeds without difficulties to afford the free trimeric, tetrameric, and pentameric oligoadenylates 15, 16, and 24 in high yields.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19830660713
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  • 9
    Electronic Resource
    Electronic Resource
    Nucleotide, XVIIITeil XVII: [1].. Synthese und Eigenschaften von (tert-Butyldimethylsilyl)guanosinen, Guanosin-3′-phosphotriestern und Guanosin-haltigen OligoncleotidenAus den Dissertationen von D.F. [2] und W.S. [3]. (1983)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 66 (1983), S. 2069-2085 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nucleotides, XVIII. Synthesis and Properties of (tert-Butyldimethylsilyl)guanosines, Guanosine-3′-Phosphotriesters and Guanosine-containing OligonucleotidesSilylation of N2-benzoyl- (1) and N2-isobutyrylguanosin (2) by tert-butyldimethylsilyl chloride led to the various mono-, di- and tri-O-tert-butyldimethylsilyl derivatives 3-15. The synthesis of 2′- (24-31) and 3′-phosphotriesters (16-23 and 32) could be achieved by phosphorylations of partially protected guanosines. The guanosine-3′-phosphodiester 33 and the 5′-OH-guanosine-3′-phosphotriester 34 are used in condensation reactions as 5′- and 3′-terminal components, respectively, to form dinucleoside mono- (39 and 40) and diphosphates (41-48) in relatively good yields. The various products were characterized by elemental analyses, 1H-, 13C-, and 31P-NMR spectra as well as UV and CD spectra.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19830660718
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  • 10
    Electronic Resource
    Electronic Resource
    Nucleotide, XXITeil XX: [1].. Synthese und Eigenschaften Dihydrouridin-haltiger Oligonucleotide (1983)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 66 (1983), S. 2641-2651 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nucleotides, XXI. Synthesis and Properties of Dihydrouridine-Containing OligonucleotidesSubstituted 5,6-dihydrouridine derivatives 1, 5, and 8 have been used in condensation reactions to form a series of dinucleosidemono- and dinucleosidediphosphotriesters, 13 and 16-22, respectively. Dihydrouridine-containing fully blocked oligomers have also been obtained by stepwise chain-elongation and block condensations including 5 trimers (25-29) and one pentamer (31), hexamer (32) and octamer (34) each. The new compounds were characterized by UV and partly CD spectra as well as elementary analyses. NMR spectra prove the structures but are not reported in detail.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/hlca.19830660832
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