Assessment of efficacy of biocides in different soil types for use in sorption studies of low molecular weight organic compounds

Soil Research ◽  
2018 ◽  
Vol 56 (5) ◽  
pp. 451 ◽  
Author(s):  
Sheridan Martin ◽  
Rai S. Kookana ◽  
Lynne M. Macdonald ◽  
Mark Farrell
Keyword(s):  
Molecular Weight ◽  
Biological Activity ◽  
Microbial Activity ◽  
Organic Compounds ◽  
Chemical Properties ◽  
Low Molecular Weight ◽  
Physico Chemical ◽  
Important Regulator ◽  
Selection For ◽  
Different Soils

The abiotic protection of low molecular weight organic compounds (LMWOC) in soils may be an important regulator of C cycling. The study of the protection of LMWOC through sorption typically employs soils shaken in solution, which may be compromised by biological activity. We used 14C-labelled glucose as a LMWOC in batch assays of four different soils with contrasting physico-chemical properties (Arenosol, Luvisol, Ferralsol and Andisol). The commonly used biocides NaN3 and HgCl2 were employed alone or in concert across a range of concentrations to assess their efficacy in inhibiting microbial degradation. For short (<1 day) sorption experiments, low NaN3 concentrations (50 µM) were sufficient to inhibit microbial activity, whereas for longer (2 week) equilibrium assays, only high HgCl2 concentrations (10 mM) were effective in all soils tested. All combinations of biocide were most effective in inhibiting microbial activity in the Arenosol and least effective in the Andisol. Thus, in some soils, particular care is required with biocide selection for complete inhibition of biological activity. The findings presented here are of relevance for the design of studies investigating sorption of labile organic compounds in soils.

Hygroscopicity of organic compounds as a function of organic functionality, water solubility, molecular weight and organic oxidation level

2021 ◽  
Author(s):  
shuang han ◽  
Juan Hong ◽  
Qingwei Luo ◽  
Hanbing Xu ◽  
Haobo Tan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Functional Groups ◽  
Organic Compounds ◽  
Water Solubility ◽  
Chemical Properties ◽  
Hygroscopic Properties ◽  
Physico Chemical ◽  
Model Predictions ◽  
Hygroscopic Behavior ◽  
Molecular Compounds

&lt;p&gt;Hygroscopic properties of 23 organic compounds with different physico-chemical properties including carboxylic acids, amino acids, sugars and sugar alcohols were measured using a Hygroscopicity Tandem Differential Mobility Analyzer (HTDMA). We converted our experimental GF data of organics at 90% RH to &amp;#954; to facilitate the comparison and we find that organic compounds with different molecular functionality present quite different hygroscopicity. Compounds with extra functional groups usually show higher hygroscopicity compared to their parental molecular compounds. Moreover, some compounds share the same molecular structure or functionality but vary differently in hygroscopicity. In general, the hygroscopicity of organics increase with functional groups in the following order: (-CH3/-NH2) &lt; (-OH) &lt; (-COOH/C=C/C=O). For highly soluble organics, the hygroscopicity decreases with molecular weight; while for slightly soluble organics which are not fully dissolved in aerosol droplets, their hygroscopicity can be divided into two categories. One is non-hygroscopic compounds, which may not fully deliquesce in the aerosol droplets. The other is moderate hygroscopic compounds, of which the hygroscopicity is mainly limited by their water solubility. Moreover, the hygroscopicity of organic compounds generally increased linearly with O:C ratios, although some of them have the same O:C ratio of but with different hygroscopicity. The experimental determined hygroscopicity are also compared with model predictions using the Extended Aerosol Inorganics Model (E-AIM) and the UManSysProp at 10-90% RH. Both models poorly represent the hygroscopic behavior of some organics, which may due to that the phase transition and intermolecular interactions are not considered in the simulations.&lt;/p&gt;

Some Physico-Chemical Properties of Low Molecular Weight Chitosans and their Relationship to Conformation in Aqueous Solution

2010 ◽  
Vol 39 (4) ◽  
pp. 575-588 ◽  
Author(s):  
Rana Obaidat ◽  
Nawzat Al-Jbour ◽  
Khaldoun Al-Sou’d ◽  
Kamal Sweidan ◽  
Mayyas Al-Remawi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Chemical Properties ◽  
Low Molecular Weight ◽  
Physico Chemical

Terpenes, Phenylpropanoids, Sulfur and Other Essential Oil Constituents as Inhibitors of Cholinesterases

2020 ◽  
Vol 27 (26) ◽  
pp. 4297-4343 ◽  
Author(s):  
Franko Burčul ◽  
Ivica Blažević ◽  
Mila Radan ◽  
Olivera Politeo
Keyword(s):  
Molecular Weight ◽  
Biological Activity ◽  
Essential Oils ◽  
Functional Groups ◽  
Organic Compounds ◽  
Chemical Structure ◽  
Low Molecular Weight ◽  
Active Compounds ◽  
Oxygenated Compounds ◽  
Nitrogen Containing Compounds

: Essential oils constituents are a diverse family of low molecular weight organic compounds with comprehensive biological activity. According to their chemical structure, these active compounds can be divided into four major groups: terpenes, terpenoids, phenylpropenes, and "others". In addition, they may contain diverse functional groups according to which they can be classified as hydrocarbons (monoterpenes, sesquiterpenes, and aliphatic hydrocarbons); oxygenated compounds (monoterpene and sesquiterpene alcohols, aldehydes, ketones, esters, and other oxygenated compounds); and sulfur and/or nitrogen containing compounds (thioesters, sulfides, isothiocyanates, nitriles, and others). : Compounds that act as cholinesterase inhibitors still represent the only pharmacological treatment of Alzheimer´s disease. Numerous in vitro studies showed that some compounds, found in essential oils, have a promising cholinesterase inhibitory activity, such as α-pinene, δ-3-carene, 1,8-cineole, carvacrol, thymohydroquinone, α- and β-asarone, anethole, etc. : Essential oils constituents are a diverse family of low molecular weight organic compounds with comprehensive biological activity. According to their chemical structure, these active compounds can be divided into four major groups: terpenes, terpenoids, phenylpropenes, and "others". In addition, they may contain diverse functional groups according to which they can be classified as hydrocarbons (monoterpenes, sesquiterpenes, and aliphatic hydrocarbons); oxygenated compounds (monoterpene and sesquiterpene alcohols, aldehydes, ketones, esters, and other oxygenated compounds); and sulfur and/or nitrogen containing compounds (thioesters, sulfides, isothiocyanates, nitriles, and others).

scholarly journals Hygroscopicity of organic compounds as a function of organic functionality, water solubility, molecular weight and oxidation level

2021 ◽  
Author(s):  
Shuang Han ◽  
Juan Hong ◽  
Qingwei Luo ◽  
Hanbing Xu ◽  
Haobo Tan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Functional Groups ◽  
Organic Compounds ◽  
Water Solubility ◽  
Chemical Properties ◽  
Molecular Formula ◽  
Differential Mobility Analyzer ◽  
Differential Mobility ◽  
Hygroscopic Properties ◽  
Physico Chemical

Abstract. Hygroscopic properties of 23 organics including carboxylic acids, amino acids, sugars and alcohols were characterized using a Hygroscopicity Tandem Differential Mobility Analyzer (HTDMA). We show that hygroscopicity of organics varies widely with different functional groups and organics with additional functional groups are more hygroscopic. However, some compounds sharing the same molecular formula or functionality show quite different hygroscopicity, demonstrating that other physico-chemical properties may contribute to their hygroscopicity as well. If the organics are fully dissolved in water (solubility > 7× 10−1 g/ml), we found that their hygroscopicity is mainly controlled by their molecular weight. For the organics that are not fully dissolved in water (slightly soluble: 5 × 10−4 g/ml < solubility < 7 × 10−1 g/ml), we observed that some of them show no obvious water uptake, which probably due to that they may not deliquesce under our studied conditions up to 90 % RH. The other type of slightly soluble organics is moderate hygroscopic and the larger their solubility the higher their hygroscopicity. Moreover, the hygroscopicity of organics generally increased with O : C ratios, although this relationship is not linear. Hygroscopicity of organic compounds were also predicted by two thermodynamic models using the Extended Aerosol Inorganics Model (E-AIM) and UManSysProp. Both models do not consider phase transition and intermolecular interactions in the simulations and show poor representation of the hygroscopicity for most of the organics.

Physico-Chemical Properties of Recombinant Desulphatohirudin

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Alpha Helix ◽  
Apparent Molecular Weight ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Recombinant Hirudin ◽  
Physico Chemical ◽  
Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

Phase-partitioning and chemical reactions of low molecular weight organic compounds in fog

Tellus B ◽  
1992 ◽  
Vol 44 (5) ◽  
pp. 533-544 ◽  
Author(s):  
M. C. Facchini ◽  
S. Fuzzi ◽  
J. A. Lind ◽  
H. Fierlinger-Oberlinninger ◽  
M. Kalina ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Compounds ◽  
Chemical Reactions ◽  
Low Molecular Weight ◽  
Phase Partitioning

scholarly journals Silver Nanoparticles Stabilized with Phosphorus-Containing Heterocyclic Surfactants: Synthesis, Physico-Chemical Properties, and Biological Activity Determination

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1883
Author(s):  
Martin Pisárčik ◽  
Miloš Lukáč ◽  
Josef Jampílek ◽  
František Bilka ◽  
Andrea Bilková ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Biological Activity ◽  
Zeta Potential ◽  
Chain Length ◽  
Alkyl Chain ◽  
Chemical Properties ◽  
Alkyl Chain Length ◽  
Microbial Pathogens ◽  
Physico Chemical ◽  
Phosphorus Containing

Phosphorus-containing heterocyclic cationic surfactants alkyldimethylphenylphospholium bromides with the alkyl chain length 14 to 18 carbon atoms were used for the stabilization of silver nanodispersions. Zeta potential of silver nanodispersions ranges from +35 to +70 mV, which indicates the formation of stable silver nanoparticles (AgNPs). Long-chain heptadecyl and octadecyl homologs of the surfactants series provided the most intensive stabilizing effect to AgNPs, resulting in high positive zeta potential values and smaller diameter of AgNPs in the range 50–60 nm. A comparison with non-heterocyclic alkyltrimethylphosphonium surfactants of the same alkyl chain length showed better stability and more positive zeta potential values for silver nanodispersions stabilized with heterocyclic phospholium surfactants. Investigations of biological activity of phospholium-capped AgNPs are represented by the studies of antimicrobial activity and cytotoxicity. While cytotoxicity results revealed an increased level of HepG2 cell growth inhibition as compared with the cytotoxicity level of silver-free surfactant solutions, no enhanced antimicrobial action of phospholium-capped AgNPs against microbial pathogens was observed. The comparison of cytotoxicity of AgNPs stabilized with various non-heterocyclic ammonium and phosphonium surfactants shows that AgNPs capped with heterocyclic alkyldimethylphenylphospholium and non-heterocyclic triphenyl-substituted phosphonium surfactants have the highest cytotoxicity among silver nanodispersions stabilized by the series of ammonium and phosphonium surfactants.

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