Some structural features of sargassan,a sulphated heteropolysaccharide from Sargassum linifolium

The acid-extractable, water-soluble, sulphated heteropolysaccharide, sargassan, contains residues of D-glucuronic acid, D-mannose, D-galactose, D-xylose, and L-fucose, and a protein moiety. Partial, acid hydrolysis of sargassan and auto-hydrolysis of the free-acid polysaccharide have been studied. Several acidic and neutral oligosaccharides were subsequently isolated. Evidence is advanced for the presence of ester sulphate on some galactose and fucose residues. It is concluded that the carbohydrate moiety of sargassan involves a backbone chain of D-glucuronic acid and D-mannose residues, and side chains involving residues of D-galactose, D-xylose, and L-fucose with sulphate attached to some galactose and fucose residues.     

Proton magnetic resonance studies of 9-(β-d-xylofuranosyl)adenine 3′,5′-cyclic monophosphate and 9-(β-d-arabinofuranosyl)adenine 2′,5′-cyclic monophosphate

A detailed ¹H 220-MHz n.m.r. study of 9-(β-d-xylofuranosyl)adenine 3′,5′-cyclic monophosphate (3′,5′-xylo-cAMP, 1) and 9-(?-d-arabinofuranosyl)adenine 2′,5′-cyclic monophosphate (2′,5′-ara-cAMP, 2) in D₂O solution is described. The sugar-ring conformations in 1 and 2 are shown to be ³E and ²E, respectively, and the phosphate rings are in a chair form. An unusual ⁴J_P,H coupling of 2.4 Hz is observed between H-4′ and phosphorus in 1 and a vicinal J_P,H of 30.8 Hz between H-5′ and phosphorus in 2. This latter coupling verifies a similar value found previously in the ara-cytidine analog of 2. A comparison of the conformational properties of cyclic nucleotides having fused phosphate and sugar rings has been made, together with an assessment of the use of the Karplus constants in such ring-systems.     

The fermentative production of acetone-butanol by Clostridium acetobutylicum.

Fourteen different media were used in the fermentative production of acetone-butanol. The highest total yields were achieved in medium I. Potato starch and soluble starch were suitable as carbon sources. The best concentrations of potato starch and soluble starch were 500.0 and 10.0 g/l, respectively. Peptone was the most favourable nitrogen source. The best concentration of peptone was 4.0 g/l. Calcium carbonate in 3.6 g/l acted as buffering agent in the fermentation process. The best initial pH value of the fermentation medium was 6.0. The optimum temperature was 32--33degreesC. The fermentation process required 120 h to obtain maximum yields of acetone-butanol.     

Characterization of Mycobacterium paratuberculosis p36 Antigen and Its Seroreactivities in Crohn's Disease

Recent data using improved cultural, molecular, and serological techniques have strengthened the association of Mycobacterium paratuberculosis with Crohn's disease, an inflammatory bowel disease (IBD) with unknown etiology. To provide more evidence of an etiological association, antibody reactivities of Crohn's disease patients were tested by immunoblotting against M. paratuberculosis–recombinant antigens. A clone containing a 1,402-bp insert and expressing a 36K-antigen (p36) was analyzed. No homology was found between the deduced amino acid sequence of p36 and any protein sequences compiled in the GenBank indicating that p36 is a novel mycobacterial protein. The reactivity of 199 serum samples was tested against the p36 by immunoblotting technique. Sera from 77 of 89 (86.5%) Crohn's disease patients and 16 of 18 (89%) sera from patients with tuberculosis and leprosy reacted with p36 compared to 5 of 42 (12%) ulcerative colitis and non-IBD control sera (p < 0.0001). In addition, p36 reacted to all sera from 10 normal controls that were Bacillus Calmette-Guerin (BCG)-immunized and only to 10% of 40 normal controls that were not BCG-immunized. The fact that sera from Crohn's disease patients reacted to p36 with the same high frequency as the sera from patients that were exposed to mycobacterial antigens further supports the hypothesis of the mycobacterial etiology in Crohn's disease. Received: 8 January 1998 / Accepted: 18 March 1999