Dimerization chromone alkaloid compound as well as preparation method and application thereof

The invention discloses a dimerization chromone alkaloid compound as well as a preparation method and application thereof. The dimerization chromone alkaloid compound is separated from the dry bark of the leguminosae cassia medicinal plant, cassia fistula, the molecular formula is C26H21NO6, and the compound is named as faistulain A with the structural formula as follows (referring to the description). The preparation method comprises the following steps: adopting the dry bark of the leguminosae cassia medicinal plant, cassia fistula, as the raw material; carrying out extractum extraction, organic solvent extraction, MCI decoloration, silica column chromatography and high pressure liquid chromatography separation, so as to obtain the compound. The compound is the first novel skeleton type dimer chromone alkaloid which is connected through C-14-N and is discovered from medicinal plants, has relatively good biological activity, can be used as a lead compound of anti-cancer drugs and anti-tobacco mosaic virus drugs, and has a relatively good application prospect.