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The present report describes a new and simple method for the detection and quantitative determination of pentoses and hexuronic acids either separately or in a mixture. The method involves treatment of the sample with sulfuric acid followed by the addition of harmine and then cysteine. Hexuronic acids produce a pink color with harmine, while pentoses react only after the addition of cysteine. Hexosamines, methylpentoses, and moderate amounts of hexoses do not interfere with these determinations. The method is simple, accurate, and allows the determination of small amounts of pentoses in the presence of larger amounts of hexuronic acids and other sugars.

An arabino 4- O -methyl glucurono xylan has been isolated as the dominant form of the hemicellulosic material of the youngest internodes of Arundo donax . The polysaccharide contained d -glucose, d -xylose and l -arabinose in the molar ratios of 0·1:9·2:0·66, respectively, with a uronic acid content of 4·5%. Methylation and periodate-oxidation showed that the xylan has a β-1 → 4-linked xylose backbone and a degree of polymerization ca. 63. The xylan is very similar to that found in the mature tissues.

A simple method for the measurement of the behavioral responses of Drosophila melanogaster to the various sugars and a method for recording nerve responses from a single chemosensory hair were described and the results were analyzed. The fly showed preference for maltose, sucrose, glucose, fructose, xylose, lactose, mannose and galactose, especially for the former four sugars, in the preference-aversion test between sugar and water. Electrophysiological responses from a labellar hair by stimulation of those sugars showed that the labellar hair examined was sensitive to maltose, sucrose, glucose and fructose, giving a series of spikes different from those initiated by NaCl and water. The magnitude of nerve responses to these four sugars was arranged in the order of the maximal number of impulses from high to low as follows: maltose, sucrose, glucose and fructose. The labellar hair examined was insensitive to xylose, lactose, mannose and galactose.

A glycopeptide was isolated from a peptic digest of ficin by successive chromatography on cationic and anionic exchange resins followed by gel filtration. The polypeptide portion of this glycopeptide consisted of 9 amino acids to which was attached a carbohydrate moiety comprised of glucosamine, mannose, galactose, fucose and xylose in molar ratios of 5:2:1:1:1, respectively. This glycopeptide appears to resemble in many respects a similar glycopeptide isolated from bromelain (Kito, K. and Murachi, T. (1969) J. Chromatogr. 44, 205–207; Scocca, J. and Lee, Y.C. (1969) J. Biol. Chem. 244, 4852–4863).

A study was made of eight dogs which had malabsorption associated with disease of the small intestine. Functional studies revealed a range of abnormalities including reduced absorption of fat and xylose, lowered disaccharidase levels in the mucosa of the small intestine, hypoalbuminemia, and protein-losing enteropathy. The morphologic abnormalities included enteritis, lymphangiectasia, and lymphosarcoma. Villous atrophy was sometimes the sole abnormality and sometimes occurred in combination with other intestinal lesions.

Previous studies have shown that D-xylose partially overcomes the puromycin inhibition of chondroitin sulfate synthesis in cultured chick embryo chondrocytes. Likewise, D-xylose stimulates chondroitin sulfate synthesis by limb bud mesenchyme cells previously treated with BrdU or limb bud cartilage cells treated with puromycin. The studies reported here show that p -nitrophenyl-β-D-xylopyranoside and 4-methyl-umbelliferyl-β-D-xylopyranoside cause a much greater stimulation than does D-xylose and are active at much lower concentrations. In contrast to D-xylose, the xylosides strikingly stimulate chondroitin sulfate synthesis in predifferentiated mesenchyme cells. The xylosides stimulate synthesis of chondroitin sulfate by rat glial cell tumor cells (RC-6), a mouse neuroblastoma (C1300, NB41A), and two strains of cultured rat hepatoma cells (HTC, H 4 ). These results indicate that certain types of nonconnective tissue cells contain the enzymic machinery for synthesis of chondroitin sulfate which is normally not utilized because of limited synthesis of core protein and/or xylosyltransferase. The β-xylosides may be used as a probe of the capacity of various cell types to synthesize sulfated glycosaminoglycans.

The benzene- and butane-boronates of arabinose and xylose have been prepared in high yield and shown to be the 1,2:3,4- and 1,2:3,5-diboronic esters, respectively. P.m.r. data indicated conformations similar to those of related acetal derivatives. The mass-spectral data are consistent with the proposed structures.

It has been shown by the methylation method that pelvecyan and sargassan are polysaccharides of similar structures with a high degree of branching of the carbohydrate chains. Fucose, xylose, and galactose are located at the nonreducing ends of their molecules, and mannose and galactose form points of branching of the carbohydrate chains of these polysaccharides.

The presence of disaccharidase-associated transport different from the Na + -dependent monosaccharide transport system in the hamster small intestine is confirmed. The transport of glucose from sucrose is substantially independent of Na + . In the absence of Na + , glucose released from sucrose does not mix with a pool of added free glucose but is directly transferred. Maltose, isomaltose and trehalose acf similarly to sucrose. Both moieties released from sucrose, glucose and fructose, are transferred. The extent of uptake is not related to total sucrase activity. The possibility is considered that the brush border disaccharidases may subserve a translocating “carrier” function for a part of the products of their enzymic action.

This paper continues the description of transketolase mutants of Escherichia coli ; they are absolutely unable to grow on pentoses, but slightly “leaky” with respect to their aromatic requirement (B. L. Josephson and D. G. Fraenkel, 1969). Several experiments have explored the degree of leakiness and shown it to be low. There is little conversion of radioactive xylose to carbon dioxide. The labeling of ribose in cells grown on [1- 14 C]glucose and [2- 14 C]glucose accords with its origin being chiefly by the oxidative pathway. A mutant lacking both transketolase and gluconate-6-phosphate dehydrogenase has been constructed; it requires supplementation with pentose. Pentoses are inhibitory to growth of transketolase mutants, but high levels of pentose phosphates do not accumulate in this situation. Several experimental results are suggestive of regulation of metabolic flow in the oxidative branch of the hexose monophosphate shunt.

Polysaccharides have been isolated from the fruit bodies of Tremella fuciformis BERK, which grows in Japan and China. Some chemical and physical properties of these polysaccharides (AC and BC : from Chinese fungus ; AJI and BJ : from Japanese fungus) were examined. The polysaccharides were homogeneous as judged by gelfiltration (Sepharose 4B), electrophoresis (Zone and Tiselius), and ultracentrifugal analysis. These polysaccharides are acidic heteroglycans composed mainly of xylose, glucuronic acid and mannose, and contain acetyl groups in their molecules (the molar ratios of them are given in Table II). The chemical properties of BC were closely similar to those of BJ in the numerical values of elemental analyses, component sugar content and acetyl content. However, significant differences were observed between BC and BJ in the physical properties, such as intrinsic viscosity, sedimentation coefficient and molecular weight.

Gastrointestinal protein loss was studied using �1 Cr-albumin in 11 patients having mild hookworm and/or roundworm infection. Of these, 7 had pure hookworm infection and 4 had combined hookworm and roundworm infection. Protein loss was normal in all patients except one in whom it was slightly increased. It is concluded that at the low levels of infectionprevalent in a community mild hookworm and mild roundworm infections at the stage of infection examined do not produce excessive gastrointestinal protein loss. Further studies in areas with heavy roundworm infection are suggested. Am. .1. Clin. Nutr. 27: 1386-1389, 1974.

The steady-level distribution coefficients (r values) between the cell water and the incubation solution are measured for a variety of small, hydrophilic, nonmetabolized nonelectrolytes in a red muscle preparation, the mouse diaphragm. Four distinct groups of solutes are discerned: large surgars, with r = 0.08; many monosaccharides, with r = 0.36; some sugars in the presence of insulin at 20 °C, and d-ribose, with r = 0.80; and all compounds tested with four carbons or less, and some sugars in the presence of insulin at 34 °C, with r = 1.00. The results can be interpreted in terms of a four-compartment model of the muscle fiber. The model requires that 64% of the cell volume be noncytoplasmic. The results are considered difficult to interpret in terms of the association-induction hypothesis of Ling. Special conditions are found under which d-xylose moves out of the muscle fiber against its concentration gradient. This observation requires either that insulin-sensitive xylose be adsorbed in the cytoplasm or that an active extrusion mechanism for sugars exists in the muscle.