Simple sugars, oligosaccharides, polysaccharides, and their derivatives, including the methyl ethers with free or potentially free reducing groups, give an orangeyellow color w-hen treated with phenol and concentrated sulfuric acid. The reaction is sensitive and the color is stable. By use of this phenol-sulfuric acid reaction, a method has been developed to determine submicro amounts of sugars and related substances. In conjunction with paper partition chromatography the method is useful for the determination of the composition of polysaccharides and their methyl derivatives.

Colorimetric Method for Determination of Sugars and Related Substances

Use of Dinitrosalicylic Acid Reagent for Determination of Reducing Sugar

A statistical mechanical treatment of high polymer solutions has been carried out on the basis of an idealized model, originally proposed by Meyer, which is analogous to the one ordinarily assumed in the derivation of the ``ideal'' solution laws for molecules of equal size. There is obtained for the entropy of mixing of n solvent and N linear polymer molecules (originally disoriented), ΔS=−k[(n/β) ln v1+N ln v2] where v1 and v2 are volume fractions and β is the number of solvent molecules replaceable by a freely orienting segment of the polymer chain. This expression is similar in form to the classical expression for equal‐sized molecules, mole fractions having been replaced by volume fractions. When the disparity between the sizes of the two components is great, this expression gives entropies differing widely from the classical values, which accounts for the large deviations of high polymer solutions from ``ideal'' behavior. The entropy of disorientation of a perfectly arranged linear polymer is found t...

Thermodynamics of High Polymer Solutions

[17] Amylases, α and β

Publisher Summary The vibrational spectrum of a molecule is determined by its three-dimensional structure and its vibrational force field. An analysis of this (usually infrared (IR) and Raman) spectrum can therefore provide information on the structure and on intramolecular and intermolecular interactions. The more probing the analysis, the more detailed is the information that can be obtained. Detailed analyses of the vibrational spectra of macromolecules, however, have provided a deeper understanding of structure and interactions in these systems. An important advance in this direction for proteins came with the determination of the normal modes of vibration of the peptide group in N-methylacetamide, and the characterization of several specific amide vibrations in polypeptide systems. Extensive use has been made of spectra-structure correlations based on some of these amide modes, including attempts to determine secondary structure composition in proteins. Polypeptide molecules exhibit many more vibrational frequencies than the amide modes. Over the years, some normal-mode calculations have provided greater insight into the spectra of particular molecules. However, these have often been based on approximate structures or have employed limited force fields. These force fields can now serve as a basis for detailed analyses of spectral and structural questions in other polypeptide molecules. The aim of this chapter is to present these recent developments in the vibrational spectroscopy of peptides, polypeptides, and proteins.

Vibrational spectroscopy and conformation of peptides, polypeptides, and proteins.

Vor 23 Jahren begannen H. MARK und der Verfasser ~mit der VerSffentlichung einer Reihe von Arbeiten fiber Konstitution und Feinbau von Hochpolymeren sowie fiber die Formen und die Form~nderungen ihrerMolektile. In der 1930 erschienenen Monographie ~¢Der Aufbau der hochpolymeren organischen Naturstoffe auf Grund molekular-morphologischer Betrachtungen~) 8 wurde von uns eine Obersicht fiber die bis dahin erhaltenen Resultate gegeben, unter denen hier aufgeffihrt seien: die Aufstellung eines Kristallmodelles ffir Zellulose 2, der heute allgemein angenommenen Cis-Polyprenformel ftir Kautschuk 4 und der Trans-Formel ffir Gutta '~, der Konstitutionsformeln und der Raummodelle ffir Chitin 5, Pektins~.ure 3, SteinnuB-Mannan a und ftir die bis dahin vSllig r~tselhafte Graphits~iure s und den ebenfalls ratselhaften elastischen SchwefeF. Es wurde auBerdem festgestellt, daI3, ~hnlictl wie es vorher (1926) von SPONSLEt~ und Done s ftir die ZelIulosefaser gezeigt worden war, auch die Seidenfaser aus parallel gelagerten fadenf6rmigen Hauptvalenzketten besteht, und es wurden die Abmessungen der Aminos~urereste angegeben 9. Dadurch wurde den yon S V E D B E R G 10 untersuehten, kompakt gebauten Proteinen, die man heute als <<globul~re, Proteine bezeichnet, das Seidenfibroin als erstes ,fibrill~res)) Protein an die Seite gestellt (vgt. Abb. 4). Das Schlul3kapitel unserer Monographie ist betitelt : (<Der Feinbau der pflanzlichen und tierischen Gewebe~ und beginnt mit den Worten:

Über Feinbau, Festigkeit und Kontraktilität tierischer Gewebe

The fine structure of potato and maize starch granules has been studied. 

1
The action of heat on the swelling of the granules has been examined. Treatment at temperatures up to 150°C diminishes the swelling in water although there is an increase in dextrinisation. This phenomenon is attributed to a growth of small crystallites at the expense of the free molecular segments, on the presence of which the swelling depends. The granules become entirely soluble at 170°.

Sur la structure fine du grain d'amidon. Recherches sur l'amidon 53

Par la methode de degradation decrite recemment, l'amylopectine est degradee par la β-amylase a 59–62%. L'arrangement des monomeres dans l'amylopectine et sa formation enzymatique sont discutes.

Recherches sur l'amidon, 41. La dégradation de l'amylopectine par la β‐amylase

1. La theorie de la permeabilite ionique de couches liquides non aqueuses est exposee. La diffusion d'ions a travers les couches huileuses est determinee par la mobilite et la solubilite des ions. Il n'existe pas de selectivite.

Kurt H. Meyer

Papers

Über Feinbau, Festigkeit und Kontraktilität tierischer Gewebe

Sur la structure fine du grain d'amidon. Recherches sur l'amidon 53

Recherches sur l'amidon, 41. La dégradation de l'amylopectine par la β‐amylase

La perméabilité des membranes. III. La perméabilité ionique de couches liquides non‐aqueuses

Recherches sur l'amidon XIII. Contribution à l'étude de l'amidon de pommes de terre