Adjuvant and pH Effects on Sethoxydim and Clethodim Activity on Rhizome Johnsongrass (Sorghum halepense)

1989 ◽  
Vol 3 (4) ◽  
pp. 615-620 ◽  
Author(s):  
David C. Bridges

Rhizome johnsongrass control with sethoxydim and clethodim was evaluated with the addition of three adjuvants: Agrioil3, BAS8153, and Li7003. Johnsongrass control was similar with the three adjuvants when either sethoxydim or clethodim was applied alone, but when bentazon was added, johnsongrass control declined with both sethoxydim and clethodim. Control generally declined less with BAS815 than with Agrioil or Li700, but the addition of BAS815 did not completely reverse the effects of adding bentazon to sethoxydim or clethodim. Johnsongrass control was not affected by adjusting pH when sethoxydim or clethodim was applied with bentazon and Agrioil. Johnsongrass control over a pH range of 3.5 to 6.5 via the addition of glacial acetic acid and calcium hydroxide or ammonium hydroxide indicated a lack of pH dependence for these herbicides. The addition of ammonium hydroxide resulted in slight, but inconsistent increases in johnsongrass control.

1973 ◽  
Vol 56 (2) ◽  
pp. 338-340
Author(s):  
Ronald L Joiner ◽  
Karl P Baetcke

Abstract Twelve thin layer chromatographic systems were compared for the separation of photoalteration products of parathion. Rf values for each component in each system are presented. Infrared spectra confirmed the identity of separated components. The following 4 systems were designated superior and gave excellent separation of the components: petroleum ether-ethyl ether-glacial acetic acid (80+15+5 and 50+45+5), methanol-chloroform-ammonium hydroxide (24+75+3.5), and methanol-chloroform-petroleum ether (10+20+70).


Author(s):  
S. Y. Ma’aruf ◽  
M. O. Mohammed ◽  
O. G. Avwioro ◽  
A. T. Muhammad ◽  
R. I. Tsamiya ◽  
...  

Introduction: Hibiscus sabdariifa is a natural dye, generally called roselle. Most of Synthetic dye  have been established to cause toxicity. The aim of this research was to determine the staining effect of different concentration of Hibiscus sabdariffa extracts at various pH, duration on fungal staining. Methods: Standard Gomori’s metenaine silver stains as control and Hibiscus sabdariffa extracts (alcoholic and aqueous) were used to stain a fungal (Aspergillus spp) positive lung tissue, using various concentration (5% and 10%) of the extract, with change of pH achieved by treating the extracts with ammonium hydroxide and glacial acetic acid at various duration (30 seconds and 1 hour respectively), each was used for staining Aspergillus spp in tissue section as a primary stain replacing (4% Chromic acid, sodium metabisulphite, Hexamine working silver solution and Sodium thiosulphate). Results: All extracts after treatment were acidic, the fungi were  best demonstrated with Aqueous hibiscus stains (5% untreated, 10% untreated and 5% glacial acetic acid treated) at longer duration, staining the capsule, light to dark-brown in a light-green background when compared with the alcoholic hibiscus stain. Few of the alcoholic hibiscus stains show metachromatic property. The Hibiscus stains stained better at longer duration and the change of pH was indirectly proportional to the staining ability of the hibiscus stains. Conclusion: The results obtained indicate that hibiscus plant extract have the potential for use in the morphological identification of fungi in formalin-fixed paraffin-embedded tissue section.


2019 ◽  
Author(s):  
Adrian Roitberg ◽  
Pancham Lal Gupta

<div>Human Glycinamide ribonucleotide transformylase (GAR Tfase), a regulatory enzyme in the de novo purine biosynthesis pathway, has been established as an anti-cancer target. GAR Tfase catalyzes the formyl transfer reaction from the folate cofactor to the GAR ligand. In the present work, we study E. coli GAR Tfase, which has high sequence similarity with the human GAR Tfase with most functional residues conserved. E. coli GAR Tfase exhibits structural changes and the binding of ligands that varies with pH which leads to change the rate of the formyl transfer reaction in a pH-dependent manner. Thus, the inclusion of pH becomes essential for the study of its catalytic mechanism. Experimentally, the pH-dependence of the kinetic parameter kcat is measured to evaluate the pH-range of enzymatic activity. However, insufficient information about residues governing the pH-effects on the catalytic activity leads to ambiguous assignments of the general acid and base catalysts and consequently its catalytic mechanism. In the present work, we use pH-replica exchange molecular dynamics (pH-REMD) simulations to study the effects of pH on E. coli GAR Tfase enzyme. We identify the titratable residues governing the pH-dependent conformational changes in the system. Furthermore, we filter out the protonation states which are essential in maintaining the structural integrity, keeping the ligands bound and assisting the catalysis. We reproduce the experimental pH-activity curve by computing the population of key protonation states. Moreover, we provide a detailed description of residues governing the acidic and basic limbs of the pH-activity curve.</div>


2008 ◽  
Vol 59 (1) ◽  
pp. 41-44
Author(s):  
Maria-Daniela Sofei ◽  
Maria Ilici ◽  
Valentin Badea ◽  
Carol Csunderlik ◽  
Vasile-Nicolae Bercean

The synthesis of 1H-3-aryl-7-ethoxycarbonyl-6-methyl-pyrazolo[5,1-c][1,2,4]triazoles (2) was carried out by cyclization of 1H-5-arylidenehydrazino-4-ethoxycarbonyl-3-methyl-pyrazoles (1) in the presence of bromine using glacial acetic acid as solvent and sodium acetate as base. The new nine obtained compounds were characterized by IR and NMR spectroscopy and mass spectrometry.


1979 ◽  
Vol 44 (8) ◽  
pp. 2330-2337 ◽  
Author(s):  
Jindřiška Maternová ◽  
Anastas A. Andreev ◽  
Dimitrii M. Shopov ◽  
Karel Setínek

It was found spectroscopically that cobalt(II) acetate dissolved in glacial acetic acid forms the octahedral complex [Co(OAc)2(HOAc)4] which in the presence of bromide ions gives the octahedral [Co(OAc)Br(HOAc)4] and tetrahedral bromo(acetate)cobalt(II) complexes with the higher number of Br- ions. When attached to an organic polymer cobalt(II) ions are bonded in the form of octahedral [Co(H2O)6]2+ cations which form with acetic acid similar complexes as in homogeneous phase and are able to coordinate one bromide ion. Drying the copolymer possessing octahedral hexaaquocobalt(II) cations leads to tetrahedral aquocomplexes which are solvated by gaseous acetic acid and converted into the acetate complexes with the liquid acid. The latter contain the acid in the inner coordination sphere and have tetrahedral symmetry.


1989 ◽  
Vol 54 (1) ◽  
pp. 64-69 ◽  
Author(s):  
Roland Meier ◽  
Gerhard Werner ◽  
Matthias Otto

Electrochemical oxidation of [V(IV)O(nta)(H2O)]- (H3nta nitrilotriacetic acid) was studied in aqueous solution by means of cyclic voltammetry, differential pulse polarography, and current sampled DC polarography on mercury as electrode material. In the pH-range under study (5.5-9.0) the corresponding V(V) complex is produced by one-electron oxidation of the parent V(IV) species. The oxidation product is stable within the time scale of cyclic voltammetry. The evaluation of the pH-dependence of the half-wave potentials leads to a pKa value for [V(IV)O(nta)(H2O)]- which is in a good agreement with previous determinations. The measured value for E1/2 is very close to the formal potential E0 calculated via the Nernst equation on the basis of known literature values for log Kox and log Kred, the complex stability constants for the oxidized and reduced form, respectively.


Author(s):  
Prabal Boral ◽  
Atul K. Varma ◽  
Sudip Maity

AbstractFour coal samples from Jharia basin, India are treated with nitric acid in glacial acetic acid and aqueous media to find out the chemical, petrographic and spatial structure of the organic mass by X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) techniques. X-ray parameters of coal like interlayer spacing (d002), crystallite size (Lc), aroamticity (fa), average number of aromatic layers (Nc), and coal rank (I26/I20) have been determined using profile-fitting software. Considerable variation is observed in treated coals in comparison to the demineralized coals. The d002 values of treated coals have increased in both the media showing increase in disordering of organic moieties. A linear relationship has been observed between d002 values with the volatile matter of the coals. Similarly, the d002 values show linear relationship with Cdmf contents for demineralized as well as for the treated coals in both the media. The Lc and Nc values have decreased in treated coals corresponding to demineralized coals. The present study shows that nitration in both the media is capable of removing the aliphatic side chains from the coals and aromaticity (fa) increases with increase in rank and shows a linear relationship with the vitrinite reflectance. The corresponding I26/I20 values are least for treated coals in glacial acetic acid medium followed by raw and then to treated coals in aqueous medium. FTIR studies show that coal arenes of the raw coals are converted into nitro-arenes in structurally modified coals (SMCs) in both the media, the corresponding bands at 1550–1490 and 1355–1315 cm−1 respectively. FTIR study confirms that nitration is the predominant phenomenon, though, oxidation and nitration phenomena takes place simultaneously during treatment with nitric acid to form SMCs. In comparison to raw coals, the SMCs show higher aromaticity and may be easily converted to coal derived products like activated carbon and specialty carbon materials.


Author(s):  
Xue Yang ◽  
Yongling Liu ◽  
Tao Chen ◽  
Nana Wang ◽  
Hongmei Li ◽  
...  

Abstract Separation of natural compounds directly from the crude extract is a challenging work for traditional column chromatography. In the present study, an efficient method for separation of three main compounds from the crude extract of Dracocephalum tanguticum has been successfully established by high-speed counter-current chromatography (HSCCC). The crude extract was directly introduced into HSCCC by using dimethyl sulfoxide as cosolvent. Ethyl acetate/n-butyl alcohol/0.3% glacial acetic acid (4: 1: 5, v/v) system was used and three target compounds with purity higher than 80% were obtained. Preparative HPLC was used for further purification and three target compounds with purity higher than 98% were obtained. The compounds were identified as chlorogenic acid, pedaliin and pedaliin-6″-acetate.


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