Physical and biological properties of cyclopolymers related to DIVEMA ("pyran copolymer").

A series of copolymers related in structure to the 1:2 alternating cyclocopolymer of divinyl ether and maleic anhydride (DIVEMA) have been shown to possess antitumor properties. The synthesis and structures of these copolymers are discussed, and their effectiveness as antitumor agents is presented. Certain of the copolymers have been prepared in controlled molecular weight ranges using chain transfer agents, and the resultant copolymers finally fractionated via use of solvent-nonsolvent systems. These samples of narrow molecular weight distribution have been evaluated for their antitumor properties and have been found to be quite effective.