New Lupanes from Alstonia scholaris Reducing Uric Acid Level.

Twelve lupanes including three new compounds named alstoscholarilups A−C (1 – 3) were isolated from the leaves of Alstonia scholaris. Their structures were elucidated by spectroscopic analysis and ECD calculation. Structurally, compound 1 with a rare A ring-seco skeleton formed lactone and degraded C-3, while 2 with a 28- nor and 3 with a 29- nor -lupane skeleton supported the phytochemical diversity and novelty of the plant. Pharmacologically, compounds 4, 7 , and 10 reduced the serum uric acid (UA) levels of mice significantly. [ABSTRACT FROM AUTHOR]