scholarly journals Distribution of enzymes in mesophyll and parenchyma-sheath chloroplasts of maize leaves in relation to the C4-dicarboxylic acid pathway of photosynthesis

1969 ◽  
Vol 114 (3) ◽  
pp. 489-498 ◽  
Author(s):  
C. R. Slack ◽  
M. D. Hatch ◽  
D. J. Goodchild
Keyword(s):  
Dicarboxylic Acid ◽  
Aqueous Media ◽  
Phosphoglycerate Kinase ◽  
Dicarboxylic Acids ◽  
Dihydroxyacetone Phosphate ◽  
Glycerate Kinase ◽  
Maize Leaves ◽  
Fractionation Pattern ◽  
Sugar Phosphates ◽  
Acid Pathway

1. Mesophyll and parenchyma-sheath chloroplasts of maize leaves were separated by density fractionation in non-aqueous media. 2. An investigation of the distribution of photosynthetic enzymes indicated that the mesophyll chloroplasts probably contain the entire leaf complement of pyruvate,Pi dikinase, NADP-specific malate dehydrogenase, glycerate kinase and nitrite reductase and most of the adenylate kinase and pyrophosphatase. The fractionation pattern of phosphopyruvate carboxylase suggested that this enzyme may be associated with the bounding membrane of mesophyll chloroplasts. 3. Ribulose diphosphate carboxylase, ribose phosphate isomerase, phosphoribulokinase, fructose diphosphate aldolase, alkaline fructose diphosphatase and NADP-specific ‘malic’ enzyme appear to be wholly localized in the parenchyma-sheath chloroplasts. Phosphoglycerate kinase and NADP-specific glyceraldehyde phosphate dehydrogenase, on the other hand, are distributed approximately equally between the two types of chloroplast. 4. After exposure of illuminated leaves to 14CO2 for 25sec., labelled malate, aspartate and 3-phosphoglycerate had similar fractionation patterns, and a large proportion of each was isolated with mesophyll chloroplasts. Labelled fructose phosphates and ribulose phosphates were mainly isolated in fractions containing parenchyma-sheath chloroplasts, and dihydroxyacetone phosphate had a fractionation pattern intermediate between those of C4 dicarboxylic acids and sugar phosphates. 6. These results indicate that the mesophyll and parenchyma-sheath chloroplasts have a co-operative function in the operation of the C4-dicarboxylic acid pathway. Possible routes for the transfer of carbon from C4 dicarboxylic acids to sugars are discussed.

scholarly journals The C4-dicarboxylic acid pathway of photosynthesis. Identification of intermediates and products and quantitative evidence for the route of carbon flow

1969 ◽  
Vol 114 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Hilary S. Johnson ◽  
M. D. Hatch
Keyword(s):  
Carbon Dioxide ◽  
Steady State ◽  
Dicarboxylic Acid ◽  
Dicarboxylic Acids ◽  
Main Flow ◽  
Carbon Flow ◽  
Dihydroxyacetone Phosphate ◽  
Carboxyl Group ◽  
Quantitative Evidence ◽  
Acid Pathway

1. When leaves with the C4-dicarboxylic acid pathway of photosynthesis are exposed to 14CO2 the major labelled compounds formed, in order of labelling, are dicarboxylic acids, 3-phosphoglycerate, bexose phosphates and sucrose. During the present studies several quantitatively minor intermediates were identified and their labelling behaviour is described. 2. The pattern of labelling of dihydroxyacetone phosphate, fructose 1,6-diphosphate and ribulose di- and mono-phosphates during radiotracer pulse–chase experiments was consistent with their operation as intermediates in the pathway of carbon dioxide fixation. 3. Serine, glycine, alanine and glutamate had labelling patterns typical of products secondary to the main flow of carbon. 4. The mechanism of the transfer of label from C-4 of dicarboxylic acids to C-1 of 3-phosphoglycerate was also examined. Evidence consistent with pyruvate being derived from C-1, C-2 and C-3 of oxaloacetate, and for a relationship between ribulose 1,5-diphosphate and the acceptor for the C-4 carboxyl group, was obtained. 5. Evidence is provided that, under steady-state conditions, essentially all the label incorporated from 14CO2 into C-1 of 3 phosphoglycerate enters via C-4 of the dicarboxylic acids. These and other studies indicated that the route via dicarboxylic acids is essentially the sole route for entry of carbon into 3-phosphoglycerate.

IR and 13C, 17O, and 119Sn NMR spectra of some bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids

1991 ◽  
Vol 56 (9) ◽  
pp. 1908-1915 ◽  
Author(s):  
Jaroslav Holeček ◽  
Antonín Lyčka ◽  
Milan Nádvorník ◽  
Karel Handlíř
Keyword(s):  
Infrared Spectroscopy ◽  
Nmr Spectroscopy ◽  
Dicarboxylic Acid ◽  
Nmr Spectra ◽  
Dicarboxylic Acids ◽  
119Sn Nmr ◽  
Carboxylic Groups ◽  
Cyclic Oligomers ◽  
The Media ◽  
Oxygen Atoms

Infrared spectroscopy and multinuclear (13C, 17O, and 119Sn NMR spectroscopy have been used to study the structure of bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids (1-C4H9)2. Sn(X(COO)2), where X = (CH2)n (n = 0-8), CH=CH (cis and trans) and C6H4 (ortho and para).The crystalline compounds are formed by linear or cyclic oligomers or polymers whose basic building units represent a grouping composed of the central tin atom substituted by two 1-butyl groups and coordinated with both oxygen atoms of two anisobidentate carboxylic groups derived from different molecules of a dicarboxylic acid. The environment of the tin atom has a shape of a trapezoidal bipyramid. When dissolvet in non-coordinating solvents, the compounds retain the oligomeric character with unchanged structure of environment of the central tin atom. In the media of coordinating solvents the bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids form complexes whose central hexacoordinated tin atom binds two molecules of the solvent trough their donor atoms. Carboxylic groups form monodenate linkages in these complexes.

scholarly journals Pharmacological activity of new imidazole-4,5-dicarboxylic acid derivatives in dopaminergic transmission suppression ttests in mice and rats

2020 ◽  
Vol 6 (4) ◽  
pp. 51-57
Author(s):  
Ekaterina E. Yakovleva ◽  
Eugeny R. Bychkov ◽  
Maria M. Brusina ◽  
Levon B. Piotrovsky ◽  
Petr D. Shabanov
Keyword(s):  
Locomotor Activity ◽  
Dicarboxylic Acid ◽  
Open Field ◽  
Field Test ◽  
Open Field Test ◽  
Dicarboxylic Acids ◽  
Dopaminergic Transmission ◽  
Dose Dependent ◽  
Derivatives Of ◽  
Experimental Improvement

Objective: To study the antiparkinsonian activity of new 1,2-substituted imidazole-4,5-dicarboxylic acids in dopaminergic transmission suppression tests in mice and rats. Materials and methods: On a model of reserpine extrapyramidal disorders, the derivatives of imidazole-dicarboxylic acids (IEM2258, IEM2248, IEM2247) were injected into the lateral brain ventricles of the mice 30 minutes after injecting reserpine at the doses of 0.1–0.5 mmol. Locomotor activity was analyzed in the Open-field test 2 hours later. In the catalepsy model, the studied agents were injected, using a pre-implanted cannula, with a simultaneous intraperitoneal injection of haloperidol. The severity of catalepsy was assessed with the Morpurgo method. Amantadine was used as a comparator drug in all the tests. Results: It was shown that IEM2258 significantly increased the main indicators of locomotor activity in the Open-field test at all the studied doses. The value of the antiparkinsonian effect of IEM2258 at doses of 0.4–0.5 mmol significantly exceeded that of amantadine. The antiparkinsonian effect of IEM2247 was maximally expressed and was significantly different from those in the control and comparator group at doses of 0.2 and 0.3 mmol. For all the experimental groups, a significant decrease in the manifestations of catalepsy in comparison with control indexes was determined. Discussion: The results made it possible to suggest the involvement of imidazole-4,5-dicarboxylic acids derivatives in the process of experimental improvement of dopaminergic neuromodulation and efficiency in animals. Conclusion: The data showed a significant dose-dependent antiparkinsonian activity of new imidazole-4,5-dicarboxylic acid derivatives, which makes it promising to develop these agents and to further search for effective and safe antiparkinsonian drugs in this pharmacological class. Graphical abstract

The effects of dicarboxylic acids on the crystal growth of α-FeOOH in aqueous media

1991 ◽  
Vol 53 (2) ◽  
pp. 209-222 ◽  
Author(s):  
Thomas F. Barton ◽  
Thomas Price ◽  
Keith Becker ◽  
John G. Dillard
Keyword(s):  
Crystal Growth ◽  
Aqueous Media ◽  
Dicarboxylic Acids

scholarly journals Two-dimensional metal-organic frameworks containing linear dicarboxylates

2006 ◽  
Vol 62 (5) ◽  
pp. 808-814 ◽  
Author(s):  
Samuel M. Hawxwell ◽  
Harry Adams ◽  
Lee Brammer
Keyword(s):  
Dicarboxylic Acid ◽  
Solvothermal Synthesis ◽  
Interplanar Spacing ◽  
Metal Organic Frameworks ◽  
Dicarboxylic Acids ◽  
Two Dimensional ◽  
Secondary Building Units ◽  
Metal Organic ◽  
Gas Molecules ◽  
Solvent Molecules

The solvothermal synthesis of four two-dimensional metal-organic frameworks containing linear dicarboxylic acids as ligands for ZnII centres is described. Zn(BDC)(DMF) [(1) where BDC = benzene-1,4-dicarboxylic acid; DMF = N,N-dimethylformamide] adopts a common paddlewheel motif leading to a 44 grid network, whereas Zn3(BDC)3(EtOH)2 (2), Zn3(BDC)3(H2O)2·4DMF (3) and Zn3(BPDC)3(DMF)2·4DMF (4) each form networks with the relatively uncommon 36 topology based upon Zn3(O2CR)6 secondary building units. All contain coordinated solvent molecules, namely DMF [(1) and (4)], ethanol (2) or H2O (3). Comparison of structures (2) and (3) illustrates a clay-like flexibility in interplanar spacing which sheds light on the ability of the Zn3(BDC)3 framework to undergo desolvation and uptake of small solvent and gas molecules.

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