Frances Rose Blase
Associate Professor of Chemistry
B.A., University of Pennsylvania
Ph.D., Bryn Mawr College
My research focuses on the enantioselective synthesis of organic molecules isolated from natural sources. In particular, we have been investigating the synthesis of secondary metabolites isolated from the myxobacterium Sorangium cellulosum. Two such metabolites are the ripostatins and the chivosazols. Myxobacteria live prefentially in soil, rotting plant material, dung and bark of living and dead trees. They have interesting motility features in that they move by gliding or creeping over the surface. Under starvation conditions, an even more unique behavior is observed in which the cells start to aggregate and pile up to produce fruiting bodies The Ripostatins, first isolated in 1996, have been reported to act as bacterial RNA polymerase inhibitors and do not show cross resistance to rifampicin, the antibiotic commonly used to treat tuberculosis. Chivosazols, also discovered in strains of Sorangium cellulosum have interesting architectural features from a synthetic standpoint, and show activity against yeasts and filamentous fungi. Progress toward the total synthesis of these two families of molecules is the major focus of our research efforts, as well as the synthesis of structural analogs for investigations into mechanism of action and structure-activity relationships.