Ion chromatographic determination of the decomposition products of tecnazene solution irradiated by ultraviolet light: inorganic and organic anions.

Ion chromatographic (IC) methods using sodium hydroxide and methanol gradients were used for the determination of small inorganic and organic anions as decomposition products of a tecnazene solution in water irradiated by UV light. After 60 min of UV irradiation, >99% of the tecnazene was decomposed, and 11 organic and 3 inorganic anions were identified and quantified. A fourth inorganic anion, carbonate, was not quantified due to likely losses as carbon dioxide. The final content of chloride, total nitrogen, and total carbon released from the saturated tecnazene solution after 60 min of UV irradiation were 108, 85, and 38%, respectively. These results suggest that other products rich in carbon and/or nitrogen (such as phenolic compounds and nitrobenzenes) were formed during the UV irradiation of the tecnazene solution. The results obtained indicate several decomposition pathways of tecnazene in water solutions, for example, ring opening reactions, dechlorination, and replacement of the ring nitro group. The determination of nonionic decomposition products from the latter two possibilities is the subject of further study.

A method to detect polysialic acid in polymers of 10 or more sialyl residues synthesized in vivo and in vitro.

An immunoaffinity column has been used to detect polysialic acid containing 10 or more sialyl residues. Antibodies specific for colominic acid were purified from horse serum by immobilized colominic acid and were bound to CH-Sepharose-4B. The immunoaffinity column was used to assay the activity of CMP-NeuNAc: poly alpha 2-->8-sialosylsialyltransferase by detecting the products which were synthesized in vitro by an extract from rat brain and CMP-[14C]NeuNAc. In addition, polysialic acid was demonstrated in a fraction of glycoproteins from human neuroblastoma cells, labeled metabolically with [3H]GlcN. The column was further characterized by binding of 3H-colominic acid and by treatment of the bound polymers with endoneuraminidase, specific for the degradation of polysialic acid. The method can be used for rapid detection of polysialic acid synthesized in vivo and in vitro.

Heat and microbial treatments for nutritional upgrading of wheat straw.

The ligninolytic activities of four cellulolytic organisms were compared using straw. Only Aspergillus japonicus and Polyporous versicolor appreciably degraded lignin with A. japonicus yielding the most protein. In solid culture, most protein was produced by P. versicolor, closely followed by A. japonicus. Pretreatment of the straw by hot water facilitated biodegradation and protein production. The nutritional value of the residual straw was also increased by some fungal cultures. The greatest amount of degradable polysaccharide in the straw was made available by A. japonicus in liquid media and Pleurotus ostreatus in solid media.

Effects of aromatic compounds on hemicellulose-degrading enzymes in Aspergillus japonicus.

Aspergillus japonicus was grown in the presence of various aromatic compounds at 0.1 and 1 mg/mL, and extracellular xylanase and arabanase activities were measured. Some of the aromatic compounds tested, especially at the higher concentration, suppressed the appearance of hemicellulase activities, expressed as xylanase or arabanase. Vanillin at 1 mg/mL in the presence of either xylan or araban completely suppressed growth, and guaiacol and p-coumaric acid markedly inhibited the growth of A. japonicus. The effects of the aromatic compounds on the activity of crude enzyme preparations were also ascertained. In vitro arabanase activity was affected more than xylanase activity.

Cord-factor analogs: synthesis of 6,6'-di-O-mycoloyl- and -corynomycoloyl-(alpha-D-galactopyranosyl alpha-D-galactopyranoside).

Appropriate solvolysis of 2,3,2',3'-tetra-O-benzyl-4,6,4', 6'-tetra-O-mesyl-alpha,alpha-trehalose gave 2,3,2',3' -tetra-O-benzyl-(alpha-D-galactopyranosyl alpha-D-galactopyranoside) (2). Selective tosylation or mesylation of 2 respectively gave the 6, 6'-ditosylate (3) and 6,6'-dimesylate (4), the structures of which were confirmed by the 1H-n.m.r. spectra of the corresponding 4,4'-di-O-acetyl derivatives. Treatment of 3 with potassium mycolate in toluene, and subsequent hydrogenolysis, gave the 6'-mycolate 6-tosylate derivative. Treatment of 3 with potassium mycolate or potassium corynomycolate in hexamethylphosphoric triamide, followed by catalytic hydrogenolysis, yielded the respective cord-factor analogs 6,6'-di-O-mycoloyl-(alpha-D-galactopyranosyl alpha-D-galactopyranoside) and 6,6'-di-O-corynomycoloyl-(alpha-D-galactopyranosyl alpha-D-galactopyranoside). The same 6,6'-diesters were obtained from the 6,6'-dimesylate 4. Putative 4,6-anhydro-6'-monomycolates are also described.

Fungal biodegradation and biotransformation of soluble lignocarbohydrate complexes from straw.

Aspergillus japonicus is an efficient degrader of phenolics and carbohydrates present in a mixture of soluble lignocarbohydrate complexes extracted from wheat straw. Trichoderma sp. attacked part of the carbohydrate but hardly affected the aromatic portion of this solution. Polyporus versicolor had a complex effect; polymerization of low-molecular-size phenolics accompanied the degradation of aromatic and carbohydrate polymers. The addition of xylose to the medium facilitated depolymerization of lignin by the fungi tested and prevented the polymerization of low-molecular-size fractions of lignocarbohydrate complexes by P. versicolor. P. versicolor, in contrast to A. japonicus and Trichoderma sp., also excreted into the medium considerable amounts of laccase, but only in the absence of endogenous or exogenous carbohydrates. Apparently, laccase is involved in polymerization rather than degradation of lignin in this organism. A number of extracellular glycanases were also secreted by these fungi.

Blood-group ABH-specific macroglycolipids of human erythrocytes: isolation in high yield from a crude membrane glycoprotein fraction.

Highly glycosylated, water-soluble ABH-specific sphingolipids, designated macroglycolipids, were isolated in high yield, up to 5 mg per unit of blood, from the crude human-erythrocyte-membrane glycoprotein fraction which is obtained by extraction of the membranes with chloroform/methanol/water. Both serological tests and radioactive labelling experiments indicated that these substances, rather than the glycoproteins, are the principal ABH-components in this fraction. The activities of A-specific, B-specific and H-specific macroglycolipids were very high, approximately 0.1 microgram inhibiting four hemagglutinating doses of the respective agglutinating reagents, and were thus comparable to those of secreted blood-group ABH-specific glycoproteins. The substances were stable to mild alkaline conditions. They contained fucose, galactose, glucosamine, glucose, sialic acid, sphingosine and fatty acids; blood-group-A-specific substances contained, in addition, galactosamine. No amino acids were detected. Assuming one glycosyl residue per molecule, the average number of sugars in A and B macroglycolipids was 31, and their molecular weights approximately 6100. The presence of beta-D-galactosidase-labile and sialic acid residues indicated that these substances contain nonreducing termini additional to the ABH immunodeterminants. In the B macroglycolipid, the ratio between nonreducing terminal alpha-D-galactopyranosyl and beta-D-galactopyranosyl residues was 1.7:1.0. The macroglycolipids formed clear aqueous solutions at concentrations as high as 30 mg/ml, were insoluble in 60--70% aqueous ethanol, and did not migrate on thin-layer chromatography unless they were acetylated. Polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate showed the macroglycolipids to be a heterogeneous mixture migrating throughout most of the region in which the periodic acid/Schiff-positive membrane glycoproteins are found. On the basis of the evidence presented, it is concluded that macroglycolipids are the predominant ABH-specific component in human erythrocyte membranes, and that they most likely account for previous observations of ABH activity in membrane glycoprotein fractions.

alpha-D-galactosidase from soybeans destroying blood-group B antigens. Purification by affinity chromatography and properties.

alpha-D-Galactosidase was isolated from untoasted soybean meal and purified to homogeneity by affinity chromatography on N-epsilon-aminoacaproyl alpha-D-galactopyranosylamine-Sepharose. The purified enzyme destroyed the B-specificity of human ovarian cyst B-glycoprotein with an accompanying increase in H-specificity, and converted human type-B erythrocytes to type O. The enzyme consists primarily of a tetramer, molecular weight 150 000 +/- 5 000 at pH 4.0 and of a monomer, molecular weight 40 000 +/- 3 000 at pH 8.0. Polyacrylamide gel electrophoresis in dodecyl sulfate at pH 7.2 distinguished between two types of monomeric unit of similar molecular weight. N-terminal alanine was identified as the sole N-terminal amino acid residue. The enzyme was shown to be devoid of carbohydrate.