X-Ray structure determination of gardmultine. A bis-indole alkaloid isolated from Gardneria multiflora Makino

Abstract

The structure of gardmultine, C₄₅H₅₄N₄O₁₀, isolated from Gardneria multiflora Makino, has been determined by single crystal X-ray analysis. The orthorhombic crystals belong to the space group P2₁2₁2₁ with a= 8.625(1), b= 20.791 (2), c= 24.494(3)Å and Z= 4. The phase problem was solved by direct methods making use of the technique of negative quartet frequencies to determine the starting set of MULTAN, and refined to a final R value of 0.053 for 3 238 observed diffractometer data taken with Cu-K_α radiation. Gardmultine is a novel bis-indole alkaloid, comprising gardneramine and chitosenine linked by a spiro-five-membered ring.