A study of the urinary excretion of digitoxin in man was first attempted by Friedman and coworkers (1) by the use of the embryonic duck heart method of biological assay. These workers estimated that the amount of cardioactive substances (calculated as digitoxin) excreted in the urine of young adults over a period of 12 to 24 days after an oral dose was equivalent to approximately 40 per cent of...

The MeOH extract from dried aerial parts of Oxypetalum caeruleum (Apocynaceae) plants yielded seventeen compounds, including four new tetracyclic triterpenoids, one pregnane glycoside, two lignane glycosides, and ten known compounds. structures the compounds were established using NMR, MS spectroscopic analysis chemical evidence.

Endoxylanases are a group of enzymes that hydrolyze the beta-1, 4-linked xylose backbone of xylans. They are predominantly found in two discrete sequence families known as glycoside hydrolase families 10 and 11. The Streptomyces lividans xylanase Xyl10A is a family 10 enzyme, the native structure of which has previously been determined by x-ray crystallography at a 2.6 A resolution (Derewenda, ...

Bacterial biofilms present a significant medical challenge because they are recalcitrant to current therapeutic regimes. A key component of biofilm formation in the opportunistic human pathogen Pseudomonas aeruginosa is the biosynthesis of the exopolysaccharides Pel and Psl, which are involved in the formation and maintenance of the structural biofilm scaffold and protection against antimicrobi...

This study characterised three aspects of cyanogenesis in the late successional tropical rainforest species Prunus turneriana (F.M.Bailey) Kalkman. First, all tissues were found to be highly cyanogenic, containing combinations of the cyanogenic glycosides ( R )-prunasin, ( S )-sambunigrin, and amygdalin. Second, the progeny of a single parent tree varied markedly and continuously in their cyano...

The possibility that endogenous inhibitors of the sodium pump exist and bind to the cardiac glycoside binding site on Na+,K+-adenosine triphosphatase (ATPase) has been a source of much controversy. Although numerous hormones and inorganic ions that modulate Na+,K+-ATPase activity have been described, most of these affect the sodium pump indirectly by varying the intracellular sodium concentrati...

Galactosaminogalactan and Pel are cationic heteropolysaccharides produced by the opportunistic pathogens Aspergillus fumigatus and Pseudomonas aeruginosa, respectively. These exopolysaccharides both contain 1,4-linked N-acetyl-d-galactosamine and play an important role in biofilm formation by these organisms. Proteins containing glycoside hydrolase domains have recently been identified within t...

1. Nitrogen enrichment is an important driver of environmental change. In the present study, plant-mediated effects of increased nitrogen on a specialist herbivore, Calophasia lunula Hufnagel, which sequesters antirrhinoside, an iridoid glycoside produced by its host plants, were examined. 2. Caterpillars were reared on Linaria dalmatica plants grown under low or high N treatments, and C. lunul...

Ouabain binding by the human erythrocyte membrane is reversible, exhibits a high degree of chemical specificity, and can be detected at ouabain concentrations as low as 1 x 10(-10)M. The relation between ouabain binding and ouabain concentration can be described by a rectangular hyperbola permitting determination of the maximal binding (B(max)) and the ouabain concentration at which ouabain bin...