Isolation, Crystal Structure, and Anti-inflammatory Activity of Sakuranetin from Populus tomentosa

The title compound of sakuranetin, a main active flavanone component, was first isolated from Populus tornentosa Can. and characterized by X-ray single-crystal diffraction analysis. It crystallizes in the monoclinic lattice, space group P2(1)/c with a = 12.8531(12), b = 5.7141(3), c = 18.0355(12) angstrom, beta = 97.333(8)degrees, V = 1313.77(16) angstrom(3), Z = 4, M-r = 286.27, C16H14O5, mu(MoK alpha) = 0.108 mm(-1), D-c = 1.447 g/cm(3), F(000) = 600, the final R = 0.0350 and wR = 0.0859 for 2571 independent reflections (R-int = 0.0246) which were used in all calculations. The molecular crystal structure of sakuranetin shows relative stereochemistry of 5,4'-dihydroxy-7-methoxyflavanone. Intermolecular hydrogen bonds together with the continuous pi-pi interactions construct the three-dimensional architecture of the title compound. The preliminary bioassay reveals that the title compound exhibits moderate anti-inflammatory activity in vitro against the nitric oxide release.