3-epi-Dammarenediol II 1.075 hydrate: A dammarane triterpene from the bark of Aglaia eximia

Abstract

The title dammarane tritepene, 3α,20(S)-dihydroxydammar-24-ene, which crystallized out in a hydrated form, C30H52O 2.1.075H2O, was isolated from the Aglaia eximia bark. The three cyclohexane rings adopt chair conformations. The cyclopentane has an envelope conformation with the quaternary C at position 14 as the flap atom with the maximum deviation of 0.288(2)Å. The methylheptene side chain is disordered over two positions with 0.505(1):0.495(1) site occupancies and is axially attached with an (+)-syn-clinal conformation. The hydroxyl group at position 3 of dammarane is in a different conformation to the corresponding hydroxyl in Dammarenediol II. In the crystal, the dammarane and water molecules are linked by ODammarane-H⋯Owater and Owater-H⋯ODammarane hydrogen bonds into a three-dimensional network.