CRYSTAL AND MOLECULAR-STRUCTURE OF 6-O-ACETYLGRAYANOTOXIN-III

The crystal and molecular structure of a grayanotoxin III derivative, 6-O-acetylgrayanotoxin ill is presented. The crystal is orthorhombic, space group P2(1)2(1)2(1), With a = 15.582(3), b = 21.304(3), c = 6.33 9(3) Angstrom, V = 2104(1) Angstrom 3, Z = 4. The structure was solved by direct methods and refined by full matrix least-squares methods to a final R = 0.047 for 1763 independent reflections with F-o > 3 sigma (F-o). The molecule is based on a tetracyclic structure consisting of two five-membered, one six-membered, and one seven-membered ring with various conformations.