Copolymers of the C9 hydrocarbon fraction of liquid pyrolysis products with maleic anhydride and their esterification products as additives to paper pulp

The influence exerted by copolymers of the C₉ fraction of liquid pyrolysis products of petroleum raw materials with maleic anhydride and by their esterification products, added to paper pulp, on the main paper properties was examined.     

MONOFUNCTIONAL3,4-and4',5'-PHOTOCYCLOADDUCTS BETWEEN 4,5'-DIMETHYLANGELICIN and THYMINE

By irradiating (365 nm) an aqueous liquid solution of 4,5'-dimethylangelicin. a monofunctional photosensitizing furocoumarin, in the presence of an excess of thymine, two new compounds, I and II, have been obtained; they do not show fluorescence when observed with Wood's light. The nuclear magnetic resonance data, the marked similarity of UV absorption and fluorescence spectra of these compounds with those of synthetic 3.4-dihydro-4,5'-dimethylangelicin and their capacity to undergo photodissociation (254 nm) yielding the starting thymine and 4,5'-dimethylangelicin in equimolecular amounts, are consistent with C₄-cycloadducts between the 3,4-double bond of the furocoumarin and 5,6-double bond of thymine. Nuclear magnetic resonance data indicate for I and II a head-to-head and a head-to-tail structure, respectively. When irradiation is carried out in the frozen state, two adducts. III and IV, fluorescent at Wood's light, have been obtained other than the two above-mentioned compounds I and II. Compounds III and IV have been identified as 4'.5'-fluorescent adducts between the 4',5'-double bond of the furocoumarin and the 5.6-double bond of thymine; one of them (III) is identical to that formed in the photoreaction between DNA and 4,5'-dimethylangelicin; for this last compound a cis head-to-head structure has been suggested.     

PHYCOBILIPROTEINS: COMPARISON OF SOLUTION AND SINGLE CRYSTAL FLUORESCENCE FOR C-PHYCOCYANIN AND B-PHYCOERYTHRIN*

Abstract— Trimeric and hexameric solution forms of C-phycocyanin (CPC) from the cyanophyte Agme-nellum quadruplicatum have been isolated and their spectral properties compared to those obtained from single crystals. Although the absorbance peak of a suspension of small C-phycocyanin crystals is red-shifted only 7 nm relative to the solution forms, the single crystal fluorescence is red-shifted 60 nm relative to the solution forms. The crystal fluorescence spectrum exhibits a single peak at LD_max= 708 nm when excited at 514.5 or 530.9 nm and two peaks (LD_max= 661 and 708 nm) when excitation occurs at 568.2 nm. Fluorescence depolarization measurements indicate that extensive energy transfer could occur for both solution and crystal forms with the latter being dependent upon the relative orientation of the crystal with respect to the excitation dipole. Similar results were obtained with B-phycoerythrin (BPE) from the red alga Porphyridium cruentum where the single crystal fluorescence is red-shifted =50nm relative to the solution spectra with two peaks (LD_max= 583 and 617 nm) observed whose relative intensities are dependent on the excitation wavelength (LD_max– 514.5 and 530.9 nm). Single crystal fluorescent lifetimes exhibited considerable shortening relative to that observed for the solution forms. The implications of these results are discussed with respect to the possible relationships of the crystalline structures to the assembly forms present within phycobilisomes.     

Tandem purification of mouse IgM monoclonal antibodies produced in vitro using anion-exchange and gel fast protein liquid chromatography

A tandem chromatographic procedure was used to isolate rapidly mouse IgM monoclonal antibodies produced by cultivation of hybridomas in vitro. Hybridoma culture supernatants containing mouse IgM monoclonal antibodies were first chromatographed on an anion-exchange Mono Q column connected to a fast protein liquid chromatography system. This anion-exchange step offers the advantage of obtaining IgM antibodies in a concentrated form. The IgM-rich fractions from the Mono Q column were then injected on a gel filtration Superose 6 column equilibrated with a low-ionic strength buffer and eluted with a high-ionic strength buffer. Assessment of the purity of isolated IgM monoclonal antibodies was performed by sodium dodecyl sulphate polyacrylamide gel electrophoresis together with a Coomassie Brillant Blue R 250 staining technique. Assessment of the immunoreactivity of isolated IgM monoclonal antibodies was performed by an enzyme linked immunosorbent assay using a solid phase adsorbed antigen against which IgM monoclonal antibodies were directed. The chromatographic procedures described allows the rapid isolation of mouse IgM monoclonal antibodies produced in vitro at a high degree of purity and in an immunoreactive state.     

Relations entre structure chimique et grandeurs de retention. VII. Composés de structure cyclopropanique

Résumé Les auteurs ont étudié le comportement chromatographique sur plusieurs phases stationnaires polaires et non polaires de composés cyclopropaniques stéréoisomêres: où R=H ou CH₃ et X=CH, COOCH₃ ou CH₂OH. Les résultats sont interprétés en fonction de la configuration de X par rapport à , de la nature électronique de X et de l'orientation du phényle par rapport au plan du cyclopropane.

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Relationship between chemical structure and retention. VII. Cyclopropane compounds

Summary The chromatographic behaviour, on several polar and non polar phases, of stereoisomeric cyclopropanes has been studied R=H or CH₃ and X=CN, COOCH₃, CH₂OH. The results are interpreted in terms of the X versus configuration, the electronic nature of X and the orientation of the phenyl ring in relation to plane of the cyclopropane ring.

     

Anwendung mikroanalytischer Methoden zur Lösung kunst- und kulturgeschichtlicher Probleme

Zusammenfassung Mit bekannten mikroanalytischen Arbeitsmethoden — Oberflächenreaktionen, Abstrichuntersuchungen mit dem Korundstäbchen, Schutzschichtreaktionen sowie dem Abdruckverfahren — lassen sich archaeometrische Probleme einer Lösung näherbringen. Die Art der Korrosion kupferhaltiger Oberflächen wurde diskutiert.

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Application of microanalytical methods to the solution of artistic- and cultural historical problems

Summary Archeometrical problems are brought closer to a solution by means of known microanalytical procedures-surface reactions, surface scraping studies with the corundum rod, protective layer reactions as well as the imprint method. A discussion of the corrosion of copper-bearing surfaces is included.

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Vortrag anläßlich der Tagung Chemische Analysen — Kunst- und Kulturwissenschaften im Reiß-Museum in Mannheim, 19.–21. September 1974.     

Electrochemical detection of tryptophan metabolites following high-performance liquid chromatography.

Electrochemical detection of tryptophan metabolites following separation on a reversed-phase high-performance liquid chromatography column was compared with other means of detection. Of 29 compounds studied, 26 could be detected at a sensitivity comparable to that of fluorescence derivatisation procedures. Response was linear over a wide range of concentrations and selectivity was shown to be superior to ultraviolet detection when analysing urine. Additionally, it was possible to control selectivity so that only those tryptophan metabolites from the tryptophan hydroxylase pathway were detected. This is of particular value in the study of distrubances of serotonin metabolism and is unique to this type of detector.     

NMR.-Investigation of the Formaldehyde Addition and Oligomerisation Equilibria in the System Formaldehyde/Water/Acetic Acid/Hydrochloric Acid

An NMR. investigation of the state of formaldehyde in acidic solutions has been carried out. Solutions of DCl/D₂O/CD₃COOD containing two sources of formaldehyde, i.e. paraformaldehyde (I) and trioxane (II), were used for this purpose. In systems I and II the effect of various D₂O/CD₃COOD ratios, at a constant DCl concentration, was studied, while for II the effect of changing DCl concentration was also investigated. The results show that in aqueous solution, formaldehyde exists primarily as the monomeric and linear oligomeric forms of methylene glycol. Reducing the amount of D₂O (at constant DCl concentration), while increasing the CD₃COOD content, results in an increase in the polymeric species and in trioxane. In addition, substitution of water by acetic acid results in systems that are catalytically more active than aqueous solutions of the same hydrochloric acid concentration. Along with the usual polymer-monomer equilibria which exist in such solutions, side reactions of methylene glycol with the hydrochloric acid present also occur to a small extent, e.g. acetylation, substitution of OH by Cl and the Cannizzaro reaction. It is suggested that these findings will result in a better understanding of the formaldehyde crosslinking reactions in cotton cellulose.     

Al(Cap)3 as initiator in the anionic polymerization of ε-caprolactam at high temperature

Mechanism for polymerization of ε-caprolactam in the presence of both sodium and aluminum caprolactamate was investigated at 171°C. The role of Al(Cap)₃ as an initiator was revealed. The apparent rate constant of propagation reaction decreased with the increase in the concentration of Al(Cap)₃, as the two different metal salts interact even at 171°C. The activation energy of the overall polymerization reaction with this catalyst system was estimated to be 41.18 kcal/mole.     

Ortho effects in organic molecules on electron impact: XI—the interesting ortho effect of the methoxy group in o-methoxy aromatic thioamides

It has been noticed that the major part of the loss of ?H from the molecular ion of most of the o-methoxythioamides results from an ortho effect of the methoxy group. Comparison of the MIKE spectra of the [M? SH]⁺ of 1-(2-methoxyphenylthioxomethyl)piperidine and 1-(2-methoxyphenylthioxomethyl)pyrrolidine with the MIKE spectra of [M? SH]⁺ of the corresponding unsubstituted compounds, reported earlier, indicated two parallel pathways for the formation of [M? SH]⁺ in the o-methoxy compounds. In the first pathway, as has been noticed in thioamides in general, the loss of ?H involves the migration of either the α-hydrogen in the amine moiety or the hydrogen attached to nitrogen. In the second pathway, the migration of a hydrogen from the o-methoxy group to the sulphur atom followed by ejection of SH from the molecular ion leads to a stable cyclized ion. Interesting secondary fragmentations as a consequence of this ortho effect have also been noticed.