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

The title dammarane tritepene, 3α,20(S)-dihydroxydammar-24-ene, which crystallized out in a hydrated form, C30H52O2.1.075H2O, 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.

The title dammarane tritepene, 3,20(S)-dihydroxydammar-24-ene, which crystallized out in a hydrated form, C 30 H 52 O 2 .1.075H 2 O, 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 O Dammarane -HÁ Á ÁO water and O water -HÁ Á ÁO Dammarane hydrogen bonds into a three-dimensional network.
The crystal packing of (I) is consolidated by intermolecular O Dammarane -H···O water and O water -H···O Dammarane hydrogen bonds ( Table 1). The molecules of 3-epi-Dammarenediol II and water molecules are linked by O-H···O hydrogen bonds into a three dimensional network (Fig. 2).

Experimental
The dried and milled bark of A. eximia (3 kg) which was collected from Bogor Botanical Garden, West Java, Indonesia, was extracted successively by n-hexane, ethyl acetate and methanol at room temperature. The ethyl acetate extract (300 g) was subjected to vacuum chromatography on silica gel G 60 by using a step gradient of n-hexane-ethyl acetate methanol. The fraction eluted by n-hexane/ethyl acetate (3:2) was further separated by column chromatography on silica gel (chloroform: methanol; 9.5:0.5 v/v) to give a colorless solid (63 mg) of the title compound. Colorless needle-shaped single crystals of the title compound suitable for X-ray structure determination were recrystallized from ethyl acetate at supplementary materials room temperature after several days.

Refinement
One of the water molecules, O3W, was refined isotropically. H atoms were positioned geometrically and allowed to ride on their parent atoms, with d(O-H) = 0.83-0.84 Å, d(C-H) = 1.00 Å for cyclic CH, 0.95 for CH, 0.99 for CH 2 and 0.98 Å for CH 3 atoms. The U iso values were constrained to be 1.2U eq of the carrier atom for all H atoms. A rotating group model was used for the methyl groups. A total of 3923 Friedel pairs were merged before final refinement. The methylheptene side chain is disordered over two sites with refined site occupancies of 0.505 (1) and 0.495 (1). The same U ij parameters were used for atom pairs C23/C24, C26/C27 and C26A/C27A. A number of reflections were omitted from the final refinement owing to poor agreement.

Figure 1
The molecular structure of the title compound, showing 60% probability displacement ellipsoids and the atom-numbering scheme. One H atom each of the O1W and O2W water molecules was generated by a symmetry operation -x, -y, z. Open bonds show the minor component. The   (Cosier & Glazer, 1986) operating at 100.0 (1) K. Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Occ. (