Effect of purine derivatives, papaverine hydrochloride, and imidazole on enterotoxin formation by Clostridium perfringens type A

The percentage sporulation and enterotoxin specific activity were improved for all of five Clostridium perfringens strains, and numbers of heat-resistant spores were improved for four of five strains by replacing proteose peptone with peptone in Duncan-Strong (DS) medium. When raffinose replaced starch in DS, peptone was superior to proteose peptone in increasing percentage sporulation, numbers of heat-resistant spores, and enterotoxin formation for four of five strains. Enterotoxin levels for a strain varied when different lots of the same peptone were used. Additional experiments were conducted with three C. perfringens strains grown in DS medium with peptone. Enterotoxin specific activity was increased for three strains by adding papaverine (hydrochloride crystalline), for two strains by adding each of caffeine and 3-isobutyl-l-methylxanthine, for one strain by adding each of theophylline, 6-mercaptopurine, and 2-amino-6-mercaptopurine, and for none of the strains by adding imidazole. When enterotoxin formation was improved for a strain by one of the compounds, percentage sporulation increased, but growth decreased. Effective compounds also increased numbers of heat-resistant spores for strains H6 and R42, but slightly or not at all for strain E13. The action of these compounds was concentration dependent, with the optimal concentration differing between compounds and between strains grown in the presence of the same compound.     

Rapid quantitative analysis of a gibberellin-sterol inhibitor using high-performance liquid chromatographic cartridge columns

A rapid, sensitive, and economical chemical analysis of the triazole, gibberellin-inhibitor, paclobutrazol (PP333, [(2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4 triazol-1-yl) pentan-3-ol]) was sought, featuring high-performance liquid chromatography (HPLC) as the final quantitation step. Three C₁₈-reverse phase columns (conventional, 250×4.6 mm; cartridge type, 125×4.6 mm; and minicolumn, 33×4.6 mm) were evaluated for their performance in HPLC separation and quantitation of PP333 applied to soil and plant foliage. The 125-mm Whatman Partisil 5 ODS-3 cartridge column was superior to the standard 250-mm DuPont Zorbax ODS unit, and provided enhanced resolution and reduced solvent consumption, analysis time, and cost. A Perkin-Elmer Pecosphere 3×3C-C₁₈ cartridge system was also superior to the 125-mm column with respect to these parameters. Although this minicolumn necessitated an additional purification step prior to HPLC analysis, its exceptionally fast analysis time and recovery period coupled with a high degree of sensitivity rendered it the most superior unit. This HPLC technology provided an efficient means of assaying for PP333 in large-scale experiments dealing with the chemical's absorption, translocation, and physiological response.