Griseofulvin

1,132,217. Griseofulvin. ARZNEIMITTELWERK DRESDEN. 24 May, 1966, No. 23175/66. Heading C2A. Two highly efficient griseofulvin-forming mutants of Penicillium urticµ Bainier, are obtained by culturing spores of a griseofulvinforming Penicillium urticµ Bainier on dehusked, swollen and sterilized millet for 14 days and subjecting the spores (a) to exposure, in a thin layer, to the irradiation of a mercury lowpressure burner with a wavelength of preferably 254 nm. at a distance of 10-50 cm. for 30 to 240 seconds, for the production of mutant M5/99 (CBS No. 235/67), (b) to suspension in 0À2-0À6 m. aqueous ethyl methane sulphonate solution for 30 to 240 minutes at 37‹ C., followed by washing with physiological saline solution, for the production of mutant M6/208 (CBS No. 236/67). A further mutant M14/260 (CBS No. 237/67) is obtained by subjecting mutant M5/99 (a) above to the mutation treatment (b) above.