During our search for new antiprotozoal (antimalarial and antitrypanosomal) agents, we have tested culture extracts of soil microorganisms from a variety of sources, including those isolated by the Kitasato Institute for Life Sciences and the Bioresource Laboratories, MicroBiopharm Japan Corporation. We have previously discovered a variety of microbial metabolites exhibiting antiprotozoal, 1,2 antimalarial 3,4 and antitrypanosomal properties. 5,6 Recently, we have isolated a new derivative of pactamycin, designated as jogyamycin (Figure 1), from a culture broth of Streptomyces sp. a-WM-JG-16.2. This compound has proved to have potent antiprotozoal activity (Table 2). Here, we report the fermentation, isolation, structure elucidation and biological activity of this novel aminocyclopentitol antibiotic.The producing organism, strain a-WM-JG-16.2 was isolated from a soil sample collected in Jogjakarta, Indonesia, using the sucrose density gradient centrifugation method. 7 Using the basic local alignment search tool (BLAST), we compared the 16S rRNA gene sequences available in the EzTaxon server to identify the species of strain a-WM-JG-16.2. Streptomyces sp. a-WM-JG-16.2 was classified as a species of the genus Streptomyces; the 16S rRNA gene sequence comparison showing a 100% similarity with S. griseoruber NBRC12873 (AB184209).The strain was cultured on a rotary shaker (220 r.p.m.) at 28 1C for 5 days in 500-ml Erlenmeyer flasks (20 flasks) containing 50 ml of a production medium containing 2% rice starch (Rose brand, Cikampek, Indonesia), 2% glucose (Univar, Sydney, NSW, Australia), 2% soybean meal (J-Oil Mills, Tokyo, Japan), 0.5% yeast extract
