Kurasoins A and B, new protein farnesyltransferase inhibitors produced by Paecilomyces sp. FO-3684. I. Producing strain, fermentation, isolation, and biological activities.

sample collected at Kurashiki City, OkayamaPrefecture, Japan. From the characteristics described below, the fungus was identified as a strain of Paecilomyces sp. For the identification of the fungus, potato-dextrose agar (PDA), yeast extract-soluble starch agar (YpSs), and corn meal agar (CMA) were used. Colonies on CMAgrew rather restrictedly, attaining a diameter of 20~25mmand was colored in pearl after incubation for 14days at 25°C. The reverse of colonies was pearl in color. No soluble pigment was produced. Morphological observation was carried out under a microscope (Olympus Vanox-S AH-2). When the strain FO-3684 was grown on CMAfor 14days at 25°C, the phialide was born directly from substrate hyphae and was hyaline with no branching as shown in Fig. 2. The phialide was swollen and tapered gradually toward the