scholarly journals THE LIMITING MECHANISM IN TARSAL CHEMORECEPTION

1951 ◽  
Vol 35 (1) ◽  
pp. 55-65 ◽  
Author(s):  
V. G. Dethier
Keyword(s):  
Partition Coefficients ◽  
Physiological Effect ◽  
Threshold Concentration ◽  
Water Soluble ◽  
Phormia Regina ◽  
Phase System ◽  
Primary Alcohols ◽  
Two Phase ◽  
The Relationship ◽  
Gain Access

Rejection thresholds of eight primary alcohols applied to the tarsal chemoreceptors of the blowfly Phormia regina Meigen and the ovipositor of Gryllus assimilis Fab. have been determined. Three different solvents for the alcohols have been used: water, ethylene glycol, and mineral oil. The comparative stimulating effectiveness of the alcohols assumes a different aspect with each different solvent. In oil the range of thresholds from methanol to octanol extends over less than one log unit as compared with the corresponding thresholds in water which extend over four log units. In glycol the thresholds extend over two and one half log units only. When water is employed as a solvent, the line which describes the relationship between threshold concentration and chain length of the compound exhibits a sharp break at or near butanol. No such discontinuity is evident when glycol or oil is employed as solvent. This is offered as evidence supporting the hypothesis that the limiting mechanism in tarsal chemoreception involves a two phase system whereby highly water-soluble compounds gain access to the receptor through an aqueous phase and the larger lipoid-soluble molecules chiefly through a lipoid phase. Additional facts which support this idea are gained from data which show that the inflection in the curve occurs at different points with different species of insects and is conspicuously absent in the case of man. When thresholds in aqueous solutions are converted from molar concentrations to activities, it is clear that the relation of equal physiological effect at equal thermodynamic activities does not apply here. The lower members of the series stimulate at progressively increasing activities up to pentanol and then at progressively decreasing activities. Furthermore, the ratio of water threshold to oil threshold exhibits no obvious agreement with the water/oil partition coefficients determined experimentally. These results indicate either that the limiting process of chemoreception in these insects does not depend upon the establishment of an equilibrium or that some kinetic effect is obscuring an underlying relationship which does so depend.

Interphase distribution of 2-furylethylenes

1985 ◽  
Vol 50 (8) ◽  
pp. 1642-1647 ◽  
Author(s):  
Štefan Baláž ◽  
Anton Kuchár ◽  
Ernest Šturdík ◽  
Michal Rosenberg ◽  
Ladislav Štibrányi ◽  
...  
Keyword(s):  
Partition Coefficient ◽  
Partition Coefficients ◽  
Transport Rate ◽  
Phase System ◽  
Two Phase ◽  
Interphase Distribution ◽  
Distribution Kinetics ◽  
System 1 ◽  
Kinetics Of

The distribution kinetics of 35 2-furylethylene derivatives in two-phase system 1-octanol-water was investigated. The transport rate parameters in direction water-1-octanol (l1) and backwards (l2) are partition coefficient P = l1/l2 dependent according to equations l1 = logP - log(βP + 1) + const., l2 = -log(βP + 1) + const., const. = -5.600, β = 0.261. Importance of this finding for assesment of distribution of compounds under investigation in biosystems and also the suitability of the presented method for determination of partition coefficients are discussed.

scholarly journals Wasserlösliche Phosphane, III [1]. Wasserlösliche primäre Phosphane mit Ammoniumgruppierungen NR2R' in der Seitenkette -donorfunktionalisierte Amphiphile / Water-Soluble Phosphanes, III [1]. Water-Soluble Primary Phosphanes with Ammonium Groups NR2R' in the Side Chain -Donor-Functionalized Amphiphiles

1994 ◽  
Vol 49 (11) ◽  
pp. 1511-1524 ◽  
Author(s):  
David J. Brauer ◽  
Jörg Fischer ◽  
Stefan Kucken ◽  
Klaus P. Langhans ◽  
Othmar Stelzer ◽  
...  
Keyword(s):  
Water Solubility ◽  
Water Soluble ◽  
Side Chain ◽  
Phase System ◽  
Alkyl Side Chain ◽  
Two Phase ◽  
Trans Conformation ◽  
Phosphonous Acid ◽  
X Ray ◽  
Superbasic Medium

Primary and secondary aminoalkylphosphanes R2N-(CH2)m-PH2 (R2 = Me2, nBu2, C5H10, C4H8O, 2-(1-Methyl-2-pyrrolidinyl); m = 2, 3, 6, 10, 11; 1-6) or [R2N-(CH2)m]2PH (7, R2 = C5H10; m = 2) are accessible by aminoalkylation of PH3 with ω̃ -chloroalkylamines R2N-(CH2)m-Cl in the superbasic medium DMSO/KOH (DMSO = dimethylsulfoxide). By selective N-quaternization of 1, 2, 4-6 with R'I (R' = Me, CnH2n+1; n = 6-8, 12, 16, 18) in the two-phase system CH2Cl2/H2O novel primary phosphanes [R'R2N-(CH2)m-PH2]+I- (11-16f) with quaternary ammonium groups in the alkyl side chain are obtained. The water solubility of 11-16f decreases with increasing chain length (n) of R′ 11 (R = R' = Me; m = 2) shows a trans conformation at the C2H4 bridge according to an X-ray structural analysis. Protonation of 1, 2, 4, 5 with HCl affords the water-soluble hydrochlorides [HR2N-(CH2)m-PH2]+Cl- (19-22). The cationic primary phosphanes 11-16f are stable towards oxygen. By oxidation of 11 with one or two equivalents of H2O2 the primary phosphane oxide [Me3N-(CH2)2-P(O)H2]+I- (23) or the phosphonous acid [Me3N-(CH2)2- P(O)(OH)H]+I- (23a) are formed. Hofmann degradation of 11 or 16c with KOH yields phosphirane in good yields. Reaction of 1, 2, 4-6 (L) with Fe2(CO)9 at ambient temperature yields stable complexes (CO)4FeL (26-30). Under more rigorous conditions Fe3 clusters (31, 32) with free R2N groups are obtained.

scholarly journals The interphase distribution of light REE Ce(III) and La(III) in system based on PEG-1500 – NaNO3 – H2O with the quaternary ammonium base addition

2022 ◽  
Vol 1212 (1) ◽  
pp. 012023
Author(s):  
A V Levina ◽  
A Ya Fedorov ◽  
M I Fedorova
Keyword(s):  
Organic Solvents ◽  
Quaternary Ammonium ◽  
Water Solution ◽  
Distribution Coefficients ◽  
Water Soluble ◽  
Process Time ◽  
Phase System ◽  
Two Phase ◽  
Quaternary Ammonium Base ◽  
Promising Alternative

Abstract The problem of e-waste processing and recovery of valuable metals from such waste for the second use is attracting more and more scientists’ attention. Liquid extraction as one of hydrometallurgy steps is a traditional method for the metal recovery. However, application of solvent extraction is not meet the green chemistry principles due to organic solvents. Aqueous two-phase systems based on water-soluble polymers are promising alternative for hazardous organic solvents. In this work the dependencies of Ce(III) and La(III) distribution coefficients from process time and the initial quaternary ammonium base concentration have been achieved. Also, based on the Ce(III) and La(III) extraction isotherms it has been shown that the metals initial concentrations are highly affects the distribution coefficients of studied metals. The possibility of aqueous two-phase system application as a solvent for quaternary ammonium salt for light REE (Ce(III) and La(III)) extraction from water solution has been shown.

Study of Aqueous Two Phase System on Water Soluble Bio Oil

2011 ◽  
Vol 236-238 ◽  
pp. 49-53
Author(s):  
Shao Peng Liu ◽  
Zhi Min Zong ◽  
Shan Shan Zhang ◽  
Yue Xu ◽  
Gui Zhen Gong ◽  
...  
Keyword(s):  
Lower Layer ◽  
Water Soluble ◽  
Extraction Rate ◽  
Phase System ◽  
Two Phase ◽  
Element Analysis ◽  
Aqueous Two Phase System ◽  
Bio Oil ◽  
Infrared Spectrometer ◽  
Aqueous Two Phase Extraction

This paper was aimed to study the aqueous two phase extraction (ATPE) on water soluble bio oil(SBO), in which ethanol, K2HPO4, NaH2PO4and (NH4)2SO4were selected to form the water soluble bio oil(SBO) aqueous two phase system (ATPS). After phase separation, the extraction rates and the volume ratios of the upper to lower layer of the ATPSs were investigeted. Both the upper and lower layers of these SBO ATPSs were analyzed by elemental analyzer and Fourier transformation infrared spectrometer (FTIR). The different extraction rates indicates the influnces of different salt during the phase saperation, of which NaH2PO4has less effect to SBO than the other two; K2HPO4may neutralize some organic acid; the lowest extraction rate of ethanol/(NH4)2SO4system indicates the effects of (NH4)2SO4to SBO. Too much ethanol will fech in more water, hence the optimizational ratio of the SBO ATPS should be SBO:salt:ethanol=10:10:5. In element analysis, the diclining of oxygen in all the upper layers and the increasing of nitrogion in both layers of (NH4)2SO4system indicates the abbility of the less oxygen components concentration of the ATPS and the reaction between (NH4)2SO4and SBO. According to FTIR test, the lack of absorption at 1515cm-1of all the lower layers indicates the completely transforming of phenols into the upper layers. Because of the high extraction rate and less influence to SBO, ethanol/NaH2PO4system may be the most suitable ATPS for SBO extraction.

Partitioning Behavior of Lysozyme and α-lactalbumin in Aqueous Two-Phase System Formed by Ionic Liquids and Potassium Phosphate

2017 ◽  
Vol 13 (10) ◽  
Author(s):  
Vanessa S. Sampaio ◽  
Renata C. F. Bonomo ◽  
Cristiane M. Veloso ◽  
Rita C. S. Sousa ◽  
Evaldo C. S. Júnior ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Partition Coefficients ◽  
Potassium Phosphate ◽  
Inorganic Salts ◽  
Phase System ◽  
Two Phase ◽  
Separation Processes ◽  
Different Temperatures ◽  
Aqueous Two Phase Systems ◽  
Increasing Temperature

AbstractNowadays ionic liquids (ILs), because of their “green” characteristics, have been used for analytical and separation processes. Therefore the partitioning of lysozyme and α-lactalbumin using aqueous two-phase systems (ATPSs) composed of an ionic liquid (chloride 1-ethyl-3-methylimidazolium) and inorganic salts (K2HPO4, KH2PO4) was studied. Phase equilibrium diagrams were obtained to explore the effect of the different temperatures (293.15, 303.15, 313.15, and 323.15) K and pH (7.5, 8.0, and 8.5) used for the partitioning studies. For both proteins, partition coefficients decreased with increasing temperature. The pH influenced the partition coefficients of lysozyme and α-lactalbumin. The thermodynamic parameters (ΔH◦, ΔS◦, ΔG◦) indicate thermodynamic differences between the partitioning of lysozyme and α-lactalbumin in this system. The ΔH◦, ΔS◦, and ΔG◦values of the process studied showed that this process is spontaneous. This work demonstrates the possible use of ATPSs with ILs and inorganic salts as a methodology for the partitioning of lysozyme and α-lactalbumin.

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