ABSTRACT
New antibiotics, phthoxazolins B, C and D were isolated from the fermentation broth of Streptomyces sp. KO-7888. They are geometrical isomers of 10-hydroxyphthoxazolin A. They showed selective antifungal activity against Phytophthora parasitica in vitro and modest herbicidal activity in a laboratory test, but the potencies were different among isomers.
Subject(s)
Antifungal Agents/isolation & purification , Fatty Alcohols/isolation & purification , Herbicides/isolation & purification , Oxazoles/isolation & purification , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Fatty Alcohols/chemistry , Fatty Alcohols/pharmacology , Fermentation , Herbicides/chemistry , Herbicides/pharmacology , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Oxazoles/chemistry , Oxazoles/pharmacology , Streptomyces , Structure-Activity RelationshipABSTRACT
A new screening method for inhibitors of cellulose biosynthesis is described. This method utilized three microbial strains; a cellulose-containing fungus Phytophthora, and a cellulose non-containing fungus Candida, and a bacterial strain of Acetobacter, a cellulose-producing acetic acid bacterium. The primary screen examined microbial cultures for selective growth inhibition against Phytophthora with no inhibition against Candida. The secondary screen tested for herbicidal activity. Thirdly, the active cultures were examined for their inhibition of cellulose biosynthesis by an Acetobacter strain. A screening trial with this new method led to the discovery of two microbial metabolites named phthoxazolin A and phthoramycin as new inhibitors of cellulose biosynthesis with herbicidal activity.
Subject(s)
Anti-Bacterial Agents/pharmacology , Cellulose/biosynthesis , Fatty Alcohols/pharmacology , Herbicides/pharmacology , Macrolides , Oxazoles/pharmacology , Acetobacter/drug effects , Candida albicans/drug effects , Microbial Sensitivity Tests , Phytophthora/drug effects , Phytophthora/growth & development , Polyunsaturated Alkamides , Structure-Activity RelationshipABSTRACT
To evaluate the diagnostic significance of the Sudan III staining for the fecal fat, the quantitative relationship between the number of fecal fat droplets examined microscopically and the amount of the fecal fat determined chemically was examined. In 43 out of 60 cases, the results of the chemical determination and the microscopic examination were in agreement and the accuracy was 72 percent. On the other hand, the false positive cases totaled 9 out of the 24 cases (37 percent) and 8 out of 9 false positive cases were diagnosed as showing a slight increase. In contrast, the false negative cases were only 2 out of 36 cases (6 percent). In addition, the comparative study of the various procedures of the Sudan III staining indicated the importance of the processing with acid and heating even in cases of steatorrhea caused by pancreatic insufficiency.
