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.     

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.     

Selective delignification of wood by white-rot fungi

The white-rot fungi,Cerrena unicolor, Ganoderma applanatum, G. tsugae,Ischnoderma resinosum, andPerenniporia medullapanis, caused two distinct types of decay. Large areas of decayed wood were selectively delignified and a typical white-rot causing a simultaneous removal of all cell wall components was present. Preferential lignin degradation was intermittently dispersed throughout the decayed wood. Scanning and transmission electron microscopy were used to identify the micromorphological and ultrastructural changes that occurred in the cells during degradation. In delignified areas the compound middle lamella was extensively degraded without substantial alteration of the secondary wall. The S₂ layer of the secondary wall was least affected. The loss of middle lamellae resulted in extensive defibration of the cells. Sulfuric acid lignin determinations indicated that 95–98% of the lignin was removed. Wood sugar analyses using high pressure liquid chromatography demonstrated that hemicelluloses were removed in preference to cellulose when lignin was degraded. The results suggest that a highly diffusible ligninolytic system was responsible for the selective degradation of the wood. In simultaneously white-rotted wood, all cell wall layers were progressively removed from the cell lumen toward the middle lamella, causing erosion troughs or holes to form. Large voids filled with fungal mycelia resulted from a coalition of degraded areas. Chemical analyses of white-rotted wood indicated lignin, cellulose, and hemicellulose were removed in approximately the same amounts. Degradation was confined to areas around fungal hyphae.     

A study of the reaction kinetics of electrogenerated superoxide ion with benzylbromide

The reaction kinetics between O₂^? and C₆H₅CH₂Br has been investigated in N,N′-dimethylformamide by electroanalytical techniques. A mechanism is proposed in which two molecules of the primary electrode product regenerate, via a following chemical reaction, one molecule of the original electroactive species. Furthermore, evidence for a S_N2 reaction mechanism between O₂^? and C₆H₅CH₂Br has been obtained. Second order rate constants resulted to be 11000 M^?1s^?1 and 3000 M^?1s^?1at room temperature and 0°C, respectively. The main products of the reaction were found to be benzylalcohol, benzaldehyde, benzene and biphenyl.     

The phase diagram for the binary system K2CrO4CaCrO4

The phase diagram for the binary system K₂CrO₄CaCrO₄ has been determined for CaCrO₄ concentrations up to 60 mole%, using the techniques of differential thermal analysis, X-ray diffraction, and drop calorimetry. Essential features of the phase diagram are: the solid-solid phase transition for pure K₂CrO₄ at 670°C, β-K₂CrO₄ ? α-K₂CrO₄; a eutectoid reaction at 14 mole% CaCrO₄ and 548°C, β-K₂CrO₄ ? α-K₂CrO₄ + K₂CrO₄ · CaCrO₄; a peritectoid event at 50 mole% CaCrO₄ and 640°C, β-K₂CrO₄ + CaCrO₄ ? K₂CrO₄ · CaCrO₄; and a eutectic reaction at 51 mole% CaCrO₄ and 678°C, L ? β-K₂CrO₄ + CaCrO₄. X-ray diffraction studies lead to the determination of the unit cell dimensions for the K₂CrO₄ · CaCrO₄ double salt, a C-centered monoclinic form with a₀ = 7.615(6) Å, b₀ = 22.797(15) Å, c₀ = 9.777(9) Å, β = 115.45(5)°.     

An optically active vinyl sulfoxide copolymer and the configuration of sulfoxide adjacent to radical or anionic sites

Optically active vinyl p-tolyl sulfoxide was synthesized and copolymerized with styrene to produce an optically active copolymer. The question of the configuration of sulfur in a sulfoxide when adjacent to a radical site is discussed. The configuration of sulfur in a sulfoxide is proven to be nonplanar when adjacent to an anionic site.     

The pectin of ginseng. The structure of the poly-galacturonide

Conclusions The partial hydrolysis of the pectin ofPanax ginseng C. A. Mey gives a polygalacturonide which has a linear carbohydrate chain consisting of residues of D-galacturonic acid in the pyranose form linked by -(1 4)-bonds.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 201–203, 1969     

Synthesis and reactions of β-(5-halo-3-uracyl) propionic acids

The reaction of elementary bromine and iodine with -(3-uracyl)-propionic acid has given the corresponding -(5-bromo-3-uracyl) and -(5-iodo-3-uracyl)propionic acids. The methyl esters and amides of the acids have also been synthesized for the first time.     

Dissociation constants of phenols in methanol--water mixtures

A preferential solvation model that relates solute properties with solvent composition in binary mixtures has been applied to the dissociation pKa values of a set of 28 substituted phenols in methanol-water mixtures. The parameters of the model allow estimation of the pKa value of each phenol for any methanol-water composition. Moreover, it is demonstrated that the pKa values of the whole set of phenols at any methanol-water composition are linearly related to the pKa values of the phenols in water. Equations that relate the correlations' slope and intercept values with the solvent composition have been derived and tested with the set of phenols. The general parameters obtained for these equations allow an accurate calculation of the pKa value of any phenol, even of those not included in the original set, at any methanol-water composition solely from the pKa value of the phenol in water. These calculated pKa values can be used for quantitative structure-HPLC retention relationships. The method is tested by comparison of the calculated pKa values with the HPLC determined pKa values of 26 phenols in a polymeric column with a 50% methanol as mobile phase.