The crystal and molecular structure of a grayanotoxin derivative, iso-graya
notoxin II, is presented. The crystal is orthorhombic, space group P2(1)2(1
)2(1,) With a = 12.357(1) Angstrom, b = 23.354(1) Angstrom, c = 6.284(2) An
gstrom, V = 1813.3(6) Angstrom(3), Z = 4. The molecule is based on a tetrac
yclic structure consisting of two five-membered, one six-membered, and one
seven-membered rings with various conformations.