Evodiamide

The title compound, C19H21N3O, was isolated from the fruits of Evodia rutaecarpa. The indole and benzene rings are both essentially planar with mean derivations of 0.0094 (4) Å and 0.0077 (3) Å, respectively. The dihedral angle between these two planes is 78.24 (9)°. The amide carbonyl plane is roughly parallel to the indole ring with a dihedral angle of 7.0 (2)°, but makes a dihedral angle of 82.9 (3)° with the benzene ring. Intermolecular N—H⋯O hydrogen-bonding interactions involving the amino and carbonyl groups give rise to a three-dimensional network.

The title compound, C 19 H 21 N 3 O, was isolated from the fruits of Evodia rutaecarpa. The indole and benzene rings are both essentially planar with mean derivations of 0.0094 (4) Å and 0.0077 (3) Å , respectively. The dihedral angle between these two planes is 78.24 (9) . The amide carbonyl plane is roughly parallel to the indole ring with a dihedral angle of 7.0 (2) , but makes a dihedral angle of 82.9 (3) with the benzene ring. Intermolecular N-HÁ Á ÁO hydrogen-bonding interactions involving the amino and carbonyl groups give rise to a three-dimensional network.

Comment
The title compound was isolated from Evodia rutaecarpa which was purchased in Japan three decades ago and its structure was determined by chemical and spectral means (Shoji et al., 1988). Since then, it was also isolated from the same herb collected in different locations of China (Tang et al., 1997;Zuo et al., 2003). Rapid detection of evodiamide and related alkaloids by LC-MS was reported (Zhou et al., 2006). It was considered a precursor of evodiamine whose crystal structure was reported (Fujii et al., 2000); however, the crystal structure of the title compound was not reported yet.
During the course of investigation of the bioactive compounds from Traditional Chinese Medicine, the title compound was isolated from Evodia rutaecarpa collected in Guangdong province of China. The colorless prisms of crystals were obtained from a methanol solution. It contains an indole ring, an amide functional group and a benzene ring ( Fig. 1). Both the indole and benzene rings are planar with a mean derivation of 0.0094 (4) Å and 0.0077 (3) Å, respectively. The dihedral angle between these two planes is 78.24 (9)°. The amide carbonyl plane is roughly parallel to the indole ring with a dihedral angle of 7.0 (2)°, but makes a dihedral angle of 82.9 (3)° with the benzene ring C13-C18. Intermolecular N-H···O hydrogen-bonding interactions (Table 1) involving the amine and carbonyl groups give a three-dimensional network (Fig. 2).

Experimental
Dried fruits (2.3 kg) of Evodia rutaecarpa (A. juss.) Benth. were milled and extracted with alcohol under reflux condition for 3 h. The alcohol extracts were filtered and concentrated to a syrup, which was suspended with water and sequentially partitioned with petroleum ether and ethyl acetate. The ethyl acetate extract (206 g) was chromatographied on silica gel with gradient elution dichloromethane-methanol to give 30 fractions. Fraction 8 eluted by dichloromethane-methanol (19:1) was further chromatographied on silica gel with chloroform-acetone (4:1) as the mobile phase to give title compound (15 mg).
Colorless crystals were obtained by recrystallization from a methanol solution.