This chemical is called Norcepharadione B, and its systematic name is 1,2-dimethoxy-4H-dibenzo[de,g]quinoline-4,5(6H)-dione. With the molecular formula of C₁₈H₁₃NO₄, its molecular weight is 307.30. The CAS registry number of this chemical is 57576-41-7. Additionally, it's isolated from houttynia cordata. 

Other characteristics of the Norcepharadione B can be summarised as followings: (1)ACD/LogP: 2.39; (2)# of Rule of 5 Violations: 0; (3)#H bond acceptors: 5; (4)#H bond donors: 1; (5)#Freely Rotating Bonds: 2; (6)Polar Surface Area: 55.84 Å²; (7)Index of Refraction: 1.699; (8)Molar Refractivity: 86.46 cm³; (9)Molar Volume: 223.7 cm³; (10)Polarizability: 34.27×10^-24cm³; (11)Surface Tension: 58.1 dyne/cm; (12)Density: 1.373 g/cm³.

You can still convert the following datas into molecular structure: 
1.SMILES: O=C4c1c3c(c(OC)c(OC)c1)c2ccccc2cc3NC4=O
2.InChI: InChI=1/C18H13NO4/c1-22-13-8-11-14-12(19-18(21)16(11)20)7-9-5-3-4-6-10(9)15(14)17(13)23-2/h3-8H,1-2H3,(H,19,21)
3.InChIKey: BAGGDUOPTSQTHD-UHFFFAOYAG