The title compound, C15H10O5¡¤H 2O, also known as emodin monohydrate, was isolated from the roots of Polygonum cuspidatum Sieb, et Zucc. It is an anthraquinone derivative, and all of its non-H atoms are essentially coplanar. Intramolecular O-H⋯O hydrogen bonds and intermolecular O-H⋯O and C-H⋯O hydrogen bonds are observed in this crystal form. The crystal structure is further stabilized by weak ¦Ð-¦Ð interactions and hydrogen bonds to the water molecule. © 2007 International Union of Crystallography. All rights reserved.

Overexpression of HER2/neu, a transmembrane tyrosine kinase acting as a coreceptor for other EGFR family members, is well known to be associated with a poor prognosis in cancer. In the present study, we observed that emodin AMAD, a novel emodin azide methyl anthraquinone derivative, extracted from the nature giant knotweed rhizome of traditional Chinese herbs, potently decreased Her2/neu protein in dose- and time-dependent manners and also inhibited the downstream MAPK and PI3K-Akt signaling pathway.