On the Diterpenoids of Andrographis paniculata: X-Ray Crystallographic Analysis of Andrographolide and Structure Determination of New Minor Diterpenoids

Abstract

The crystal structure of andrographolide (8) was determined and the absolute configuration at C-14, which was previously undecided, was established as R. Reexamination of the constituents of Andrographis paniculata Nees Resulted in the isolation of three new diterpenoids of ent-labdane type, andrographanin, andropanoside, and 14-deoxy-12-methoxy-andrographolide, together with three known compounds, 14-deoxyandrographolide (4), neoandrographolide (5) and andrographolide (8). The structures of the new diterpenoids were determined to be 1, 2, and 3 on the basis of spectral and chemical evidence. © 1984, The Pharmaceutical Society of Japan. All rights reserved.