A new antibiotic, which we named deoxydynemicin A (1, Fig. 1), was produced together with dynemicin A1} (2, Fig. 1) in the culture broth of a strain of actinomycetes, MG331-hF6, which was isolated from a soil sample collected on Mt. Minobu, Yamanashi Prefecture, Japan. The strain was classified as Micromonospora globosa MG331 hF6 by taxonomic studies and deposited in the Fermentation Research Institute of the Agency of Industrial Science and Technology, Japan, with the accession No. FERM P-10651. Antibiotic 1 inhibited the growth of bacteria very strongly. Here, we report the production, isolation, properties, structure, and biological activities of 1 and NMR studies of 2.