Abstract
Damavaricin C, a degradative derivative of streptovaricin C, has a new active hydroxyl group at the C-19 position of the naphthoquinone moiety where various groups can be substituted by ether linkage. The biological activities of these ethers were compared against animal cells, including normal, virus transformed, and human cancer cells in vitro. Some of derivatives showed preferential lethal activity on virus transformed cells in vitro.