Reinvestigation of the root of Rhinacanthus nasutus afforded, in addition to rhinacanthin-A to -D reported previously, two new dimethyldihydropyranonaphthoquinone esters (5, 6) and eight new 2-hydroxy- 1,4-naphthoquinone esters (7-14) were isolated. The stereochemistry of rhinacanthin-A was determined as the R configuration. Compounds rhinacanthin- G to -N, belong to a class of 2-hydroxy-3-(3-hydroxy-2,2-dimethylpropyl)- 1,4-naphthoquinone esters, and so far have been isolated only in this plant. Their biosynthesis is also discussed.
All Science Journal Classification (ASJC) codes
- Drug Discovery