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1Author    Jörg Fleischhauer3, Sven Gabriel3, A.Ndreas Job3, D. Ieter Enders3, Axel WollmerbRequires cookie*
 Title    CD-Spectroscopic Investigations for the Determination of the Absolute Configuration of (4/?,6S,7S)-Serricomin  
 Abstract    The absolute configuration of the conformationally flexible (4i?,6S,7S)-serricornin, a non­ natural isomer of the female-produced sex pheromone of the cigarette beetle (Lasioderma serricorne), was determined by comparison of measured and calculated circular dichroism spectra. The rotational strengths were calculated by means of the semiempirical CNDO/2S-method. The total synthesis was accomplished by the SAMP/RAMP-hydrazone method. 
  Reference    Z. Naturforsch. 56b, 1344—1348 (2001); received July 26 2001 
  Published    2001 
  Keywords    Serricornin, CD Spectra, Absolute Configuration 
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 TEI-XML for    default:Reihe_B/56/ZNB-2001-56b-1344.pdf 
 Identifier    ZNB-2001-56b-1344 
 Volume    56 
2Author    KhalidM. Ohammed Khana, Farnaz Malikb, Mashooda Hasanb, Shahnaz Perveen3, Jodwiga Frelekc, G. Ünther Snatzke+, Wolfgang Voelter3Requires cookie*
 Title    Circular Dichroism Studies on New Optically Active 1,5-Benzodiazepine Derivatives  
 Abstract    From thirty three new optically active 1,5-benzodiazepine derivatives the UV and CD data are reported and the bands discussed related to corresponding electronic transitions respectively stereochemical features. 
  Reference    Z. Naturforsch. 51b, 588—598 (1996); recieved September 26 1995 
  Published    1996 
  Keywords    CD Spectra, Benzodiazepines, Chiral 1, 5-Benzodiazepine Derivatives 
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 TEI-XML for    default:Reihe_B/51/ZNB-1996-51b-0588.pdf 
 Identifier    ZNB-1996-51b-0588 
 Volume    51 
3Author    Jörg Fleischhauer3, Sven Gabriel3, Dieter Enders3, Anja Nühring3, Axel WollmerbRequires cookie*
 Title    CD-Spectroscopic Investigations for the Determination of the Absolute Configuration of a-Alkylated 1,4-CycIohexanedione Derivatives  
 Abstract    The absolute configuration of the conformationally flexible six membered ring system 2-me-thyl-and 2,6-dimethyl-l,4-cyclohexanedione monoethylene acetal was determined by compar­ ison of measured and calculated CD spectra. The rotational strengths were calculated by means of the CNDO/S-method assuming R at the stereogenic center. The results were compared with the predictions made by the octant rule. The enantiomerically pure material was synthesized via the corresponding SAMP-and RAMP-hydrazones. 
  Reference    Z. Naturforsch. 55b, 1011—1014 (2000); received July 3 2000 
  Published    2000 
  Keywords    1, 4-Cyclohexanedione Derivatives, Absolute Configuration, CD Spectra 
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 TEI-XML for    default:Reihe_B/55/ZNB-2000-55b-1011.pdf 
 Identifier    ZNB-2000-55b-1011 
 Volume    55 
4Author    Henri Brunner, Jean-Claude LeblancRequires cookie*
 Title    (CH2OCH3)P(C6H5)2N(CH3)R * mit chiralen Fe-Atomen Optically Active Transition Metal Complexes, LXX [1] Preparation of the Optically Active Diastereoisomers CsHsFe^O)- (CH2OCH3)P(C6H5)2N(CH3)R* with Chiral Fe Atoms  
 Abstract    The two diastereoisomers CsHsFe(CO)(CH2OCH3)P(CeHs)2N(CH3)R* (Ba, b), with R* = 0S)-CH(CH3)(C6H5), differing only in the Fe configuration, have been obtained by photochemical reaction of C5H5Fe(C0)2CH20CH3 with (£)-(+)-P(C6H5)2N(CH3)R*. The optically pure isomer 3 a can be isolated by chromatography at low temperature; its chiroptical properties are discussed. 
  Reference    Z. Naturforsch. 35b, 1491—1493 (1980); eingegangen am 8. August 1980 
  Published    1980 
  Keywords    Diastereoisomers, Fe-Configuration, Separation, CD Spectra 
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 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-1491_n.pdf 
 Identifier    ZNB-1980-35b-1491_n 
 Volume    35 
5Author    DevinderK. Anand, MichaelK. Hargreaves, MohsinA. KhanRequires cookie*
 Title    Conformational Studies of R-(-f)-2-Alkylidene-and R-(—)-2-Benzylidene-5-methylcyclohexanones  
 Abstract    The eis and trans 2-alkylidene-5-methylcyclohexanones have been separated and distinguished. 2-Benzylidene-5-methylcyclohexanone was also prepared in both forms. The CD, ORD, UV and IR spectra are recorded and discussed. The NMR data include solvent and temperature effects. 
  Reference    Z. Naturforsch. 36b, 978—988 (1981); received December 1 1980/April 8 1981 
  Published    1981 
  Keywords    2-Alkyl/arylidene-5-methylcyclohexanones, CD Spectra, ORD Spectra, NMR Spectra 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-0978.pdf 
 Identifier    ZNB-1981-36b-0978 
 Volume    36 
6Author    Kaeko Kikuchi, Yoshio Taniyama, Ryuji MarumotoRequires cookie*
 Title    Evaluation of the 2 NH 2 A—T Pair in Hybridization, I Synthesis of the DNA/RNA Hybrid Oligomers Containing 2-Aminoadenosines  
 Abstract    DNA decamers containing 2-aminoadenosine were synthesized. Oligonucleotide duplexes in-cluding the 2 NH2A—T base pairs were prepared and their Tm profile examined. Contrary to expectation, elevation of the Tm value by the 2 NH2 group is very small in DNA/RNA duplexes. From the CD spectra measurement, we assume that the distortion of the B-DNA structure caused by scattered DNA/RNA base pairing diminishes the efficient hydrogen bonding and base stacking of the duplexes. It was also found that the DNA duplexes containing 2-aminoadenosine hybrids are considerably resistant to ribonuclease T2 or nuclease PI digestion. 
  Reference    Z. Naturforsch. 43b, 623—630 (1988); received October 12 1987/February 1 1988 
  Published    1988 
  Keywords    DNA Probe, Hybridization, 2-Aminoadenosine, CD Spectra, DNA/RNA Hybrid Oligomer 
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 TEI-XML for    default:Reihe_B/43/ZNB-1988-43b-0623.pdf 
 Identifier    ZNB-1988-43b-0623 
 Volume    43 
7Author    Zofia Plesnar3, Stanisław Malanowski3, Zenon Lotowskib, JacekW. Morzyckib, Jadwiga Frelek, Jacek WójcikdRequires cookie*
 Title    Stereospecific Association of C-20 Epimers of 3/?-Hydroxy-16-oxo-24-nor-17-azachol-5-eno-23-nitryle  
 Abstract    The cryoscopic measurements show that title compounds are strongly associated in CHC13 solutions. The association of the 20 R epimer is distinctly less pronounced than that of the 205 epipmer. Self-association of the 205 epimer leads to the formation of very large com­ plexes. The 20 R epimer forms associates via water molecules. The dissimilarity may be ex­ plained in terms of different accessibility of the lactam carbonyl groups in the two epimers for the association. It is proposed that the association process is controlled by the configura­ tion at the carbon atom C(20) and conformation around the C(20)-C(22) bond. Populations of side chain conformations of both epimers were determined by means of proton nuclear magnetic resonance. It was found for the 20 R epimer that the t and the -g rotamers are almost equally populated, and the rotamer +g is excluded. For the 205 epimer the +g rotamer predominates over the t one, and the -g rotamer is excluded. The N M R data are fully consistent with the results of the molecular modelling studies. 
  Reference    Z. Naturforsch. 52b, 749—756 (1997); received 
  Published    1997 
  Keywords    Self-Association, Cryoscopic Measurements, Conformational Analysis, CD Spectra, Azasteroids 
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 TEI-XML for    default:Reihe_B/52/ZNB-1997-52b-0749.pdf 
 Identifier    ZNB-1997-52b-0749 
 Volume    52 
8Author    Thomas Buhse, Wolfram ThiemannRequires cookie*
 Title    Chiral Intermediates and the Oscillatory Effect of Circular Dichroism in the Belousov -Zhabotinskii Type Reaction of L-Ascorbic Acid  
 Abstract    Investigating the Belousov-Z habotinskii (BZ) type reaction of an acidic L-ascorbic acid (AA) / potassium brom ate / cerous sulfate system, an oscillatory effect of circular dichroism is detectable at A = 300 nm. HPLC analysis o f the oscillatory mixture and spectroscopic experi­ ments indicate that this effect is caused by 3,4,5-trihydroxy-2-oxo-L-valeraldehyde (TVA) -a C5 oxidation fragment of AA. Because of the bromide ion production occurring before the metal catalyst addition the AA system shows no preoscillatory phase and a rather short entire length of oscillation up to a maximum of 20 min. Since AA is not brom inated but oxidized by bromine which is formed by the Landolt typ "clock reaction" o f AA with acidic brom ate, par­ tially bromine-hydrolysis-controlled (BHC) oscillations are discussed for the overall mecha­ nism of this BZ system. 
  Reference    Z. Naturforsch. 46b, 1406—1414 (1991); received 
  Published    1991 
  Keywords    M arch 1, 1991 Chemical Oscillations, CD Spectra, L-Ascorbic Acid, B elousov-Z habotinskii Reaction, Bromate 
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 TEI-XML for    default:Reihe_B/46/ZNB-1991-46b-1406.pdf 
 Identifier    ZNB-1991-46b-1406 
 Volume    46 
9Author    Z. NaturforschRequires cookie*
 Title    Über die Darstellung sowie Elektronen-und CD-Spektren der Co(I)-Form einiger natürlicher Corrinoide  
 Abstract    Synthesis and S pectra (E lectronic, C D) o f the C o(I) F o rm o f Several N atu ra l C orrinoids M atthäus M oskophidis Several natural corrinoids, cobalam in, 5-hydroxybenzim idazolyl cobam ide (factor III), adenyl cobam ide (pseudovitam in Bi2), 2-m ethyladenyl cobam ide (factor A) and cobyric acid, were reduc­ ed with sodium borohydride. The reduction o f cyanocobalam in is slow as com pared with that o f factor III and especially o f the other corrinoids under study. At longer wavelengths (A > 300 nm) the electronic spectra o f the Co(I)-corrinoids are nearly identical. The same is to say about the CD-spectra o f the Co(I)-corrinoids examined. 
  Reference    Z. Naturforsch. 34c, 689 (1979); eingegangen am 19. Februar/9. April 1979 
  Published    1979 
  Keywords    Vitamin B12, B12-Analogues, Co(I)-corrinoids, Electronic Spectra, CD-Spectra 
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 TEI-XML for    default:Reihe_C/34/ZNC-1979-34c-0689.pdf 
 Identifier    ZNC-1979-34c-0689 
 Volume    34 
10Author    Z. NaturforschRequires cookie*
 Title    Coa/Coß-Isomerie der am Kobalt methylierten Corrinoide. Über die CD-und ORD-Spektren einiger Isomerenpaare  
 Abstract    The CD and ORD spectra o f the Coar-and Co/?-methyl isomers o f cobalamin, 2-methylthio-adenyl cobamide (factor S), cobyric acid and /?-kresyl cobamide (factor lb) were recorded in water and acidic solution. In complete and incomplete (nucleotide free) (Coar-methyl)-corrinoids the axial ligands CH3 and HzO are unalterable (fixed) within a wide range o f pH (about 1 to 12) at room temperature in the dark. Thus the spectra in this pH range are constant at X > 350 nm; spectral differences at X < 350 nm are effects of the nucleotide bases. The spectra o f complete "base-on" (Co/?-methyl)-corrinoids are, like the spectra of (Coa-methyl)-corrinoids, at X > 350 nm not dependent on the nucleotide base. If the nucleotide base is not coordinated ("base-off'), the spectra change strikingly and at X > 350 nm are nearly identical with those o f incomplete corrinoids e. g. cobyric acid. 
  Reference    Z. Naturforsch. 36c, 497 (1981); eingegangen am 16. Oktober 1980/25. Februar 1981 
  Published    1981 
  Keywords    gewidmet Vitamin B12, Methyl Corrinoids, Coa/Co/?-Isomerism, CD Spectra, ORD Spectra 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0497.pdf 
 Identifier    ZNC-1981-36c-0497 
 Volume    36