Solid Phase Behavior in the Chiral Systems of Various 2-Hydroxy-2-phenylacetic Acid (Mandelic Acid) Derivatives

2015 ◽  
Vol 60 (3) ◽  
pp. 721-728 ◽  
Author(s):  
Jan von Langermann ◽  
Erik Temmel ◽  
Andreas Seidel-Morgenstern ◽  
Heike Lorenz
Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 671 ◽  
Author(s):  
Shigesaburo Ogawa ◽  
Isao Takahashi

Although the anomalous low crystallinity of octyl β-D-glucoside (β-OGlu) was first proposed more than 30 years ago, many fundamental aspects of its crystal structure and of the crystalline phase behavior of the pure substance have remained uncertain. In this paper, we employ grazing-incidence wide-angle X-ray-diffraction measurements using a two-dimensional detector (2D-GI-WAXD) and perpendicularly aligned crystalline films to demonstrate that β-OGlu forms crystal structures consisting of an intermediate phase—like a ripple phase with two large crystal-lattice constants, a and c, comparable to the lengths of its bilayer structures. Furthermore, solid-to-solid phase transitions accompanied by latent heat confirm the existence of a solid-solution-like phase consisting of a crystalline and a liquid-crystal (LC) phase, which persists over a 20 °C temperature range, in a single-component system. In addition, the system forms a superlattice, accompanied by a change in packing of the component sugars in the partial-melting state; this shift is different from the gel-crystal transition observed for a typical lipid system. These facts indicate that even in the crystalline phase formed from a single component, each individual β-OGlu molecule in a single-component phase plays a versatile role in the crystallisation and melting processes. These findings must somewhat explain the specific co-assembling features with proteins of β-OGlu, which has long been used empirically in biochemistry.


1983 ◽  
Vol 14 (31) ◽  
Author(s):  
M. G. TAYLOR ◽  
E. C. KELUSKY ◽  
I. C. P. SMITH ◽  
H. L. CASAL ◽  
D. G. CAMERON

1961 ◽  
Vol 1 (03) ◽  
pp. 195-212 ◽  
Author(s):  
J.J. Taber ◽  
I.S.K. Kamath ◽  
Ronald L. Reed

Abstract Alcohol floods of consolidated sandstone cores have shown the process to be strongly dependent on the phase behavior of the particular alcohol-oil-water system used. This means that in many cases the mechanism does not conform to the idea of a piston-like displacement. Instead, it is found that by changing the alcohol it is possible to change the relative velocities of the oil and water and, in fact, the entire mechanism of the process. The effects of rate, viscosity, initial saturation, distance travelled and hysteresis of relative permeability on the alcohol flooding mechanism are discussed. Introduction Reasons for interest in the use of alcohol to miscibly displace oil and water from a porous medium appear in the existing literature. The mechanism of the displacement has been considered and the apparent implications formulated into a theory which presumably would enable one to predict the essential features of the process. Unfortunately, most of the reported experiments have been performed with unconsolidated or artificially consolidated sands. With these systems some of the noteworthy facets of the process are obscured and resulting data appear uncertain. It is the purpose of this paper to show how the use of consolidated sandstones has led to revision of the mechanism and, hence, the theory of alcohol flooding. The practical result is increased pessimism toward the possibilities of commercial application of the simplest form of the alcohol-slug process. However elucidation of the mechanism has made it possible to define the essential characteristics of a system of slugs which will behave in a nearly piston-like fashion and, thus, yield the best possible result. Equilibrium Phase Behavior Fig. 1 is a diagram of the ternary system isopropyl alcohol (IPA)-Soltrol-calcium chloride brine. Brine was used to prevent plugging of the core and calcium chloride was used because sodium chloride brine exhibits a solid phase with Soltrol and IPA. If alcohol is added in increments to the immiscible mixture of water and oil represented by Point A, the path followed by the successively equilibrated samples will be on the Line ABC and pass from the immiscible region to the miscible region by crossing the binodal curve at B. Consider the intersection D of this path with the tie Line EF. The quantity of oleic phase is proportional to the Segment ED and the quantity of the aqueous phase is proportional to DF. Compositions of the two phases are specified by Points E and F. It is clear that in the case shown the oleic phase is diminishing and entirely disappears when miscibility is achieved.


1959 ◽  
Vol 37 (5) ◽  
pp. 1085-1100 ◽  
Author(s):  
A. C. Neish

A number of C14-labelled compounds were fed to detached leafy twigs of Colorado spruce (Picea pungens Engelm.), and after a metabolic period of 24 hours the pungenin was isolated and the specified activities of the glucose moiety and the aglycone (3,4-dihydroxyacetophenone) were determined. In some instances the aglycone was degraded further to determine the C14 in the methyl and carbonyl carbons separately.Caffeic acid and L-phenylalanine were the best precursors of the aglycone; cinnamic acid, p-coumaric acid, phenyllactic acid, and shikimic acid were quite good. Sodium acetate was a poor precursor, and was converted to glucose more readily than to the aglycone. Compounds found to be very poor precursors include tyrosine, 3,4-dihydroxyphenylalanine, 3-hydroxytyramine, phenylacetic acid, mandelic acid, p-hydroxyphenylpyruvic acid, p-hydroxyphenyllactic acid, p-hydroxybenzoic acid, and protocatechuic acid. Cinnamic acid-α-C14 gave 3,4-dihydroxyacetophenone labelled chiefly in the methyl group, while cinnamic acid-β-C14, L-phenylalanine-β-C14, p-coumaric acid-β-C14, and caffeic acid-β-C14 formed 3,4-dihydroxyacetophenone labelled mainly in the carbonyl carbon. It appears that a phenylethanoid compound is formed by a process involving the loss of the terminal carbon of a phenylpropanoid compound.3,4-Dihydroxyacetophenone-carbonyl-C14 was fed to spruce twigs bearing new terminal growth; up to 20% was converted to pungenin but most of it formed unidentified compounds. It was a poor precursor of lignin, compared with cinnamic acid, and a poor precursor of glutamic acid, relative to acetate.


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