DUCLAUXIN ETHYL-ACETATE SOLVATE, 2C(29)H(22)O(11)CENTER-DOT-C4H8O2

Duclauxin, [8R-(8 alpha,8a beta,15a beta,15b 3,4,5-d'e']bis[2]benzopyr an-3,7,12,15(8H)-tetrone, cocrystallized with ethyl acetate solvent (2 :1). Duclauxin, an antitumor agent, when isolated from Penicillium her quei displays an unusually low melting point (469-471 K) compared with duclauxin from P. duclauxii or P. stipitatum (503 and 508-509 K, resp ectively), even though all spectral characterizations of duclauxin fro m these three sources indicate identical substances. The X-ray structu ral analysis of duclauxin from P. herquei reveals the presence of an e thyl acetate molecule, which is a likely explanation for the abnormal melting point. The duclauxin molecular structure consists of two large ly planar halves which are held by the remaining atoms into an approxi mate open clam-shell configuration. Significant intramolecular hydroge n bonding is observed between the phenolic hydroxyl groups and lactoni c carbonyl O atoms; the only significant intermolecular hydrogen bondi ng is between the ketonic O(3) atom of one duclauxin molecule to the p henolic O(6) atom in the other. There are no especially close intermol ecular contacts between ethyl acetate and either of the duclauxin mole cules.