scholarly journals Changes of humic acids structure on selected key monitoring localities of arable soils

2011 ◽  
Vol 48 (No. 1) ◽  
pp. 40-44 ◽  
Author(s):  
G. Barančíková

Soil fertility is largely determined by the content and quality of soil organic matter. SlovakRepublic monitoring system includes evaluation of soil humus content, basic humic parameters and also chemical structure of humic acids (HA). Changes in humic acids structure on five selected key localities during monitoring period (1994&ndash;2000) are presented in this study. Among soil types, essentially between Chernozem and Planosol, in elemental analysis, optical parameter and 13C NMR parameters significant differences determined by Student&rsquo;s test were observed (Tables 2 and 3). During monitoring period small oxidation trend mainly on Calcaric Fluvisol and Planosol HA expressed by increase of oxygen content and O/C, O/H ratio was observed. Oxidation trends during monitoring period confirm also position of Calcaric Fluvisol and Planosol HA on van Krevelen diagram. Changes in optical parameter E<sup>1%</sup><sub>6</sub>and content of carboxylic groups for the period of monitoring were negligible. Some changes throughout monitoring in <sup>13</sup>C NMR parameters were recorded. On all observed HA considerable decrease of carbon in region 106&ndash;143 ppm, characteristic for aromatic and olefinic carbon with C&ndash;C, C&ndash;H bond, was observed. Spectroscopic parameters are in good agreement with elemental analysis and carboxylic groups. Joint relationships between changes in determined parameters are expressed by significant linear correlations. Predominantly between parameters calculated from <sup>13</sup>C NMR spectra and data of elemental analysis and optical parameter E<sup>1%</sup><sub>6</sub>highly significant linear correlations (R &gt; 0.93) are found (Table 4).&nbsp;

2019 ◽  
Vol 1 (1) ◽  
pp. 29-32
Author(s):  
Ruzimurod B. Boimurodov ◽  
Zebinisso Q. Bobokhonova

In this article is showing, that the irrigation mountain brown carbonate soils prone methods of irrigation and grassing comes the rapid growth and development of natural vegetation, which leads to intensive humus accumulation. Humus content in the upper layer is increased by 0.98% and a significantly smaller severely eroded. Increasing the amount of humus promotes accumulation mainly humic acids, that conducts to expansion of relations the content of humic acid: The content of folic acid. When grassing of soil traced sharp increase in the number associated with the related and R2 O3 humic acid.


1989 ◽  
Vol 69 (2) ◽  
pp. 253-262 ◽  
Author(s):  
M. SCHNITZER ◽  
P. SCHUPPLI

Organic matter (OM) in the Bainsville and Melfort soils, and in coarse clay and medium silt fractions separated from these soils, was extracted under N2 with 0.5 M NaOH and unadjusted 0.1 M Na4P2O7 solutions. pH ranges of the soils and fractions in contact for 24 h with 0.5 M NaOH and 0.1 M Na4P2O7 solutions extended from 12.2 to 12.6 and 9.0 to 9.4, respectively. Slightly greater proportions of the soil-carbon were extracted by 0.5 M NaOH than by 0.1 M Na4P2O7 solution. The differences, however, did not appear to be significant and may vary from soil to soil. The efficiency of extraction and the characteristics of the extracted materials were assessed on humic acids (HAs), which were isolated from the extracts. From the Bainsville soil and fractions, 0.1 M Na4P2O7 solution extracted more high-molecular weight and more deeply colored HAs than did 0.5 M NaOH solution. But HAs extracted from the Melfort soil and fractions had similar molecular weights and colours. 13C NMR spectra showed that HAs extracted by 0.1 M Na4P2O7 solution tended to be more aromatic than HAs extracted by 0.5 M NaOH solution. Well defined solid-state 13C NMR spectra of HAs, containing up to 69.0% ash, could be recorded. Unadjusted 0.1 M Na4P2O7 solution under N2 was found to be an attractive alternative to 0.5 M NaOH solution as an extractant for soil OM. Key words: Humic acids, E4:E6 ratios, IR spectra, 13C NMR spectra, aromaticity


Author(s):  
Aseel Alsarahni ◽  
Zuhair Muhi Eldeen ◽  
Elham Al-kaissi ◽  
Ibrahim Al- Adham ◽  
Najah Al-muhtaseb

<p><strong>Objective: </strong>To design and synthesize amino acetylenic and thiocarbonate of 2-mercapto-1,3-benthiazoles as potential antimicrobial agents.</p><p><strong>Methods: </strong>A new series of 2-{[4-(t-amino-1-yl) but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole derivatives (AZ1-AZ6), and S-1,3-benzothiazol-2-yl-O-alkyl carbonothioate derivatives were synthesised, with the aim that the target compounds show new and potential antimicrobial activity. The elemental analysis was indicated by the EuroEA elemental analyzer, and biological characterization was via IR, <sup>1</sup>H-NMR, [13]C-NMR, DSC were determined with the aid of Bruker FT-IR and Varian 300 MHz spectrometer using DMSO-d<sub>6</sub> as a solvent.<em> </em><em>In vitro </em>antimicrobial activity, evaluation was done for the synthesised compounds, by agar diffusion method and broth dilution test. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined. <em></em></p><p><strong>Results: </strong>The IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, DSC and elemental analysis were consistent with the assigned structures. Compound of 2-{[4-(4-methylpiperazin-1-yl)but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole (AZ1), 2-{[4-(2-methylpiperidin-1-yl)but-2-yn-1-yl]sulfanyl}-1,3-benzothiazole (AZ2), 2-{[4-(piperidin-1-yl) but-2-yn-1-yl]sulfanyl}-1, 3-benzothiazole (AZ6), S-1,3-benzothiazol-2-yl-O-ethyl carbonothioate (AZ7), and S-1,3-benzothiazol-2-yl-O-(2-methylpropyl) carbonothioate (AZ9) showed the highest antimicrobial activity against <em>Pseudomonas aeruginosa </em>(<em>P. aeruginosa</em>), AZ-9 demonstrated the highest antifungal activity against <em>Candida albicans </em>(<em>C. albicans</em>), with MIC of 31.25 µg/ml.</p><p><strong>Conclusion: </strong>These promising results promoted our interest to investigate other structural analogues for their antimicrobial activity further.</p>


2005 ◽  
Vol 60 (10) ◽  
pp. 1049-1053 ◽  
Author(s):  
Zeanab Talaei ◽  
Ali Morsali ◽  
Ali R. Mahjoub

Two new ZnII(phen)2 complexes with trichloroacetate and acetate anions, [Zn(phen)2(CCl3COO)- (H2O)](ClO4) and [Zn(phen)2(CH3COO)](ClO4), have been synthesized and characterized by elemental analysis, IR, 1H NMR, 13C NMR spectroscopy. The single crystal X-ray data of these compounds show the Zn atoms to have six-coordinate geometry. From IR spectra and X-ray crystallography it is established that the coordination of the COO− group is different for trichloroacetate and acetate. The former acts as a monodentate whereas the latter acts as a bidentate ligand.


2020 ◽  
Vol 49 (46) ◽  
pp. 16903-16915
Author(s):  
Mehmet Sevim ◽  
Serdar Batıkan Kavukcu ◽  
Armağan Kınal ◽  
Onur Şahin ◽  
Hayati Türkmen

A series of RuII (1), RhIII (2), IrIII (3, 4), IrI (5) and PdII (6–9) complexes of the ‘instant carbene’ nitron were prepared and characterized by 1H- and 13C-NMR, FT-IR and elemental analysis. They were used to form C–C coupling reactions.


2014 ◽  
Vol 69 (9-10) ◽  
pp. 969-981 ◽  
Author(s):  
Olcay Bekircan ◽  
Emre Mentese ◽  
Serdar Ulker

Abstract In the present investigation, the key intermediate acetohydrazide derivative 5 was synthesized starting from 3-(4-methoxybenzyl)-4-amino-4,5-dihydro-1,2,4-triazol-5-one (1) by a four-step reaction. Thiosemicarbazides 6a-f and arylidenehydrazide derivatives 8a-d were obtained from compound 5. The cyclization of compounds 6a-f in the presence of NaOH resulted in the formation of compounds 7a-f. The compounds were characterized by IR, 1H NMR, 13C NMR spectroscopy, elemental analysis and mass spectral studies. The compounds were tested for their anti-lipase, anti-α-glucosidase and anti-mycobacterial activities. Compounds 6b and 8c exhibited excellent anti-lipase activity, and compound 8d showed excellent anti-a-glucosidase activity. Compounds 3 and 4 exhibited good antituberculosis activity


2009 ◽  
Vol 64 (9) ◽  
pp. 1065-1069 ◽  
Author(s):  
Mehdi Rimaz ◽  
Jabbar Khalafy ◽  
Khadijeh Tavana ◽  
Katarzyna Ślepokura ◽  
Tadeusz Lis ◽  
...  

Diethyl 2,2´-thiocarbonyl-bis(azanediyl)dibenzoate was synthesized from the reaction of ethyl anthranilate with thiophosgene. Its treatment with sodium ethoxide in ethanol at room temperature gave ethyl 2-(4-oxo-2-thioxo-1,2-dihydroquinazolin-3(4H)-yl) benzoate, whereas in the presence of ethyl nitroacetate and under the same reaction conditions, the corresponding bis(quinazolin)disulfide was formed. Its structure was confirmed by IR, 1H and 13C NMR spectroscopy elemental analysis and single crystal X-ray structure determination.


2005 ◽  
Vol 2005 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Minati Baral ◽  
B.K. Kanungo ◽  
Peter Moore

Some novel organic compounds of the type: cis, cis-1,3,5-tris(X)cyclohexane, where X= –CONH(CH2)2NH2, –CONH(CH2)3NH2, –CONH(CH2)2NCH –C6H4OH, CONH(CH2)3NCHC6H4OH, which are expected to function as potential polydentate chelators have been synthesised from 1,3,5-benzenetricarboxylic acid through multi-steps reactions. 1,3,5-benzenetricarboxylic acid was reduced to cis, cis-1,3,5-tris(ethylcarboxylate)cyclohexane, which on reaction with excess of 1,2-diaminoethane and 1,2-diaminopropane afforded two new compounds. Condensation of the obtained derivatives with three equivalents of salicylaldehyde resulted the formation of two new Schiff base compounds. All the compounds were characterised by a combination of elemental analysis, mass, IR, UV-Vis, 1H NMR and 13C NMR spectroscopy.


1992 ◽  
Vol 70 (3) ◽  
pp. 809-816 ◽  
Author(s):  
Brigitte Duthu ◽  
Karim El Abed ◽  
Douraid Houalla ◽  
Robert Wolf ◽  
Joël Jaud

The sulfuration of the tricyclic organophosphorous dimer 2 leads easily to the dithiotricyclic derivative 3, which has been characterized by 31P, 1H, and 13C NMR, elemental analysis, and mass spectroscopy. Its crystal and molecular structure has been established by X-ray diffraction and compared to that of 2, which was previously determined. The comparative analysis of X-ray diffraction and NMR parameters gives accurate information about the molecular structure of both compounds. A numerical value of the anistropy cone of the P=S double bond is proposed. Keywords: phosphecine, NMR, X-ray, tricycle.


2008 ◽  
Vol 63 (3) ◽  
pp. 275-279 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Ezzat Khan ◽  
Rhett Kempe

Protodeborylation of triorganoboranes, usually carried out under mild reaction conditions using an excess of acetic acid, affords 1,5-dialkyl-3,7-dimethyl-4,8,9-trioxa-2,6-dioxonia-1,5-diboratabicyclo [3.3.1]nona-2,6-dienes OB(R)OC(Me)OB(R)OC(Me)O [1 (R = Et), 2 (R = cyclooctyl)]. Acetoxy(dialkyl) boranes and di(acetoxy)alkylboranes were not formed in an appreciable amount. Compounds 1 and 2 were characterized by NMR spectroscopy (1H, 11B, 13C NMR) in solution, the molecular structure of 2 was determined by X-ray analysis. The gas-phase geometry of 1 was optimized by calculations [B3LYP/6-311+G(d, p) level of theory], and its NMR parameters were also calculated at the same level of theory.


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