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1978 (2)
1977 (2)
1975 (1)
1Author    Requires cookie*
 Title    Radiation Chemistry of Carbohydrates, X* y-Radiolysis of Crystalline D-Glucose and D-Fructose  
 Abstract    i z d a r o g l u , D. H e n n e b e r g , K . N e u w a l d , G. S c h o m b u r g and C. v o n S o n n t a g In stitu t für Strahlenchemie im M ax-Planck-Institut für Kohlenforschung, Mülheim a. d. Ruhr a-D-Glucose and ß-D-fructose were y-irratiated in the solid (polycrystalline) state at room temperature at doses o f 3.5 • 1020-4 .2 • 1021 eV g-1 (dose rate 1.16 • 1018 eV g_1 min_1). Carbohydrate products containing < 6 carbon atoms were identified and their G-values (in parentheses) measured. Glucose: Dihydroxyacetone (1) (0.05), 3-deoxy-tetrose (2) (O.OI5), l,4-dideoxy-2-pentu-lose (3) (0.05), 2,4-dideoxy-pentose (4) (O.O8 5), 2,4-dideoxy-pentonic acid (5), 2,3-dideoxy-pentos-4-ulose (6) (together 0.03a), threose (7), erythrulose (8), erythrose (9), erythronic acid (10) (together 0.04), l-deoxy-2-pentulose (11) (0.005), 2-deoxy-ribose (12) (0.25), 3-deoxy-pentosulose (13) (0.02), 3,5-dideoxy-hexonic acid (14) (0.02), 2,3-dideoxy-hexonic acid (15) (0.01), arabinose (16) (0.25), ribose (17), ribonic acid (18) (together 0.02), 2-deoxy-2-C-hydroxymethyl-pentonic acid (19) (0.06), 5-deoxy-gluconic acid (20), 2-deoxy-5-keto-glucose (21), 2-deoxy-gluconic acid (22), 2-deoxy-3-keto-glucose (23), 3-deoxy-glucosone (24), 3-deoxy-gluconic acid (25), 3-deoxy-4-keto-glucose (26), 3-deoxy-mannonic acid (27) (together 0.4). Identified but nor measured quantitatively were glucosone (28), 3-keto-glucose (29), 4-keto-glucose (30), 5-keto-glucose (31) and gluconic acid (32). G(H2) = 5.75; G (C02) = 0.7. Fructose: 7-9 (together 0.65), 3-deoxy-pentonic acids (37), 3-deoxy-pentosulose (38) (together 0.3), arabonic acid (39) (0.1), 18 (0.05), 6-deoxy-2,5-hexodiulose (40) (40). Identified but not measured quantitatively were glyceraldehyde (34), butanone-(3)-diol-(l,2) (35) and 2 -and 3-deoxy-hexodiuloses. G(H2) = 4.75, G (C02) = 0.05. Reaction schemes are proposed to account for the form ation of the products. The scission of the hemiacetal bond and of the C-H and C-C bonds next to it appears to be typical for solid state irradiations. The formation of deoxy-compounds is observed both in the solid state and in aqueous solution. The form ation o f dideoxy-compounds is only prominent in the solid state. In polycrystalline fructose a chain reaction is induced leading to 6-deoxy-2,5-hexodiulose (40). 
  Reference    (Z. Naturforsch. 32b, 213—224 [1977]; received October 27 1976) 
  Published    1977 
  Keywords    GC-MS, G-Values, Radical Reactions, Chain Reaction 
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 TEI-XML for    default:Reihe_B/32/ZNB-1977-32b-0213.pdf 
 Identifier    ZNB-1977-32b-0213 
 Volume    32 
2Author    Requires cookie*
 Title    Radiation Chemistry of Carbohydrates, XV OH Radical Induced Scission of the Glycosidic Bond in Disaccharides  
 Abstract    H e n r y k Z e g o t a * * a n d C l e m e n s v o n S o n n t a g In the y-radiolysis of deoxygenated, NaO-saturated aqueous solutions of maltose, lactose, gentiobiose, melibiose, trehalose and sucrose carbohydrate products containing five or six carbon atoms have been identified and their G-values measured. These products originate from the OH radical induced scission of the glycosidic bond of the disaccharides. The nature of the products is in agreement with a reaction scheme proposed previously for the radical induced scission of the glycosidic bond of cellobiose. It involves hydrolysis and the rearrangements of radicals with the free spin next to the glycosidic bond and to the lactol bridge. The nature the glycosidic bond (a, ß, 1-4, 1-6, 1-1, 1, 2) has only little influence on the G-values of its scission which range between about 1.9 and 3.5. 
  Reference    (Z. Naturforsch. 32b, 1060—1067 [1977]; received May 31 1977) 
  Published    1977 
  Keywords    y-Radiolysis, G-values, Mass Spectra, Radical Reactions 
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 TEI-XML for    default:Reihe_B/32/ZNB-1977-32b-1060.pdf 
 Identifier    ZNB-1977-32b-1060 
 Volume    32 
3Author    Claus FriebelRequires cookie*
 Title    Investigations with Respect to the Structure of Cu(II)-compounds by EPR and Ligand Field Spectroscopy  
 Abstract    From EPR and ligand field param eter some significant structural details of Cu(II)-compounds can be determined to a notable accuracy: a) the sym m etry (tetragonal or o-rhombic) of Jahn-T eller distorted octahedral Cu(II)-sites, and b) the ordering o f Jahn-Teller coupled Cu(II)-polyhedra with respect to each other as well as to the crystallographic axes of the Cu(II)-compound under investiga­ tion. 
  Reference    (Z. Naturforsch. 30b, 970—972 [1975]; eingegangen am 26. Juli 1975) 
  Published    1975 
  Keywords    g-Values, Ligand Field Parameters, Structural Deductions, Copper(II)-compounds 
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 TEI-XML for    default:Reihe_B/30/ZNB-1975-30b-0970_n.pdf 
 Identifier    ZNB-1975-30b-0970_n 
 Volume    30 
4Author    Alfred Hissung, Clemens Von SonntagRequires cookie*
 Title    Radiolysis of Cytosine, 5-Methyl Cytosine and 2'-Deoxycytidine in Deoxygenated Aqueous Solution A Pulse Spectroscopic and Pulse Conductometric Study of the OH Adduct  
 Abstract    Using the pulse radiolysis technique the OH adducts of cytosine, 5-methyl cytosine and 2'-deoxycytidine were investigated in alkaline N20 saturated aqueous solutions. Ab-sorption spectra were recorded and their change with time was correlated with the change in conductivity. An OH -induced reaction (1.4 • 10 8 1 • mol -1 • s -1) was observed with OH adducts of cytosine and 5-methyl cytosine leading to radicals (pK = 10.3), the G-values of which were 3.2 and 1.6 respectively (conductivity measurements). These intermediates were assigned to the C-5 OH radical adducts. After completion of the free radical reactions (2k = 6 • 10 8 1 • mol -1 • s -1) the resulting product mixture showed pK-values of 8.3 (cytosine, G = 0.6), 10.5 (5-methyl cytosine, G = 0.8), 10.7 (cytosine, G=1.5; 2'-deoxycytidine, G=1.5) and 12.4 (cytosine, no G-value, determinable with optical detection). Ammonia, which is a product measured after y-radiolysis of all the three compounds investigated (G(NHs) = 0.6 ± 0.1), is not released within 15 ms after the pulse. 
  Reference    Z. Naturforsch. 33b, 321—328 (1978); received November 25 1977 
  Published    1978 
  Keywords    Cytosine, G-Values, pK-Values, Absorption Spectra, Pulse Radiolysis 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0321.pdf 
 Identifier    ZNB-1978-33b-0321 
 Volume    33 
5Author    BarryJ. Parsons, Dietrich Schulte-Frohlinde, Clemens Von SonntagRequires cookie*
 Title    Reaction of Br3' 2 -with 2-Deoxy-D-ribose. A Preferred Attack at C-l  
 Abstract    In the photolysis of 5-bromouracil containing DNA Br atoms are expected inter mediates. In order to evaluate the possible site of attack of the Br atom at the sugar moiety of DNA the reaction of 2-deoxy-D-ribose with the Br atom (complexed with two bromide ions) was investigated. Hydroxyl radicals generated by the radiolysis of N20 saturated aqueous solutions were converted into Br3 -2_ radicals by 1 M bromide ions. Br3-2-reacts with 2-deoxy-D-ribose (k = 3.7 • 10 4 M -1 s -1 , pulse radiolysis). The major product is 2-deoxy-D-erythro-pentonic acid (G = 2.4, y-radiolysis). It is formed by hydrogen abstraction from C-l and oxidation of this radical by other radicals. An alternative route via the radical at C-2 is neglible. It follows that Br3-2 ~ reacts preferentially at C-l of 2-deoxy-£>-ribose. 
  Reference    Z. Naturforsch. 33b, 666—668 (1978); received March 15 1978 
  Published    1978 
  Keywords    Pulse Radiolysis, y-Radiolysis, 2-Deoxy-D-ribose, G-values, Radical Reactions 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0666.pdf 
 Identifier    ZNB-1978-33b-0666 
 Volume    33