A new tetranortriterpenoid from the roots of Atalantia buxifolia.

A new tetranortriterpenoid, named 6-deacetyl-severinolide (1), together with six known tetranortriterpenoids severinolide (2), acetyl-isoepiatalantin (3), 7-isovaleroylcycloepiatalantin (4), cycloepiatalantin (5), 7-isovaleroylcycloseverinolide (6), and atalantin (7), was isolated from the ethanol extract of the roots of Atalantia buxifolia collected in Hainan. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR (HMQC, 1H–1H COSY, HMBC, and NOESY). [ABSTRACT FROM AUTHOR]