Evaluation of Mannich bases of styryl ketones and related hydrazones for activity against P388 leukemia.

A Mannich base namely 4-dimethylaminomethyl-1-phenyl-1-penten-3-one hydrochloride was shown to have far greater activity than 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) towards P388 leukemia cells in vitro. However, the compound was inactive in an in vivo P388 murine screen, and the object of this study was to discern molecular features which conferred in vivo activity. Mannich bases containing electron-attracting substituents in the aryl ring had in vivo potency in contrast to the analogs which had electron-donating groups in the ring. A number of hydrazones of the Mannich bases were prepared as potential prodrugs and did not enhance bioactivity. This observation was probably due to a lack of facile hydrolysis of the hydrazones to the corresponding Mannich bases in vivo since high resolution 1H NMR spectroscopy revealed that representative hydrazones either did not regenerate the ketones or produced them only in minute quantities at pH values normally encountered in living tissues.

Klebsiella serotype K39: structure of an unusual capsular antigen deduced by use of a viral endoglucosidase.

Methylation analysis and graded acid hydrolysis showed that the capsular polysaccharide of Klebsiella K39 is of the "5 + 1" type and that the repeating unit contains two nonequivalent residues of D-glucopyranosyluronic acid, one of which constitutes the branch point. A decision between two possible structures, in favor of that shown below, was reached by examination of the hexasaccharide obtained by depolymerization using phage luminal diameter 39, which possessed an endo-beta-D-glucosidase. Anomeric configurations were assigned by analysis of 1H- and 13C-n.m.r. spectroscopic data for the polysaccharide and oligosaccharides derived therefrom. The following structure is proposed for the Klebsiella K39 antigen: -3(Glc beta 1-4)GlcA beta 1-2Man alpha 1-4GlcA beta 1-2Man alpha 1-3Glc beta 1- The polysaccharide is the first in the Klebsiella genus thus far reported to contain two uronic acid residues per repeating unit.

Preparation of oligosaccharides by the action of bacteriophage-borne enzymes on Klebsiella capsular polysaccharides.

Depolymerization of bacterial, capsular polysaccharides by viral enzymes provides a convenient method for preparing oligosaccharides that correspond to one or more repeating unit(s) of the polysaccharide. Previous methods used for purifying bacteriophage particles, and also the procedures employed in the isolation and purification of the oligomers generated by the bacteriophage action, have been so modified as to provide a more direct route to the degradation products. Improved techniques, both for the propagation of bacteriophage and for the isolation of the oligosaccharides formed, are reported. These simplified methods make possible the use of bacteriophages as convenient "reagents" for the preparation of oligosaccharides on a gram scale. The acid- and base-labile substituents present in certain of the polysaccharides examined were seemingly unaffected by the conditions used for depolymerization. The methods are illustrated by degradation of the capsular polysaccharides from Klebsiella serotypes K17, K36, K46, K60, K63, and K74