Micrandilactone A:  A Novel Triterpene from <i>Schisandra </i><i>m</i><i>icrantha</i>

[structure: see text] A novel nortriterpene, micrandilactone A, was isolated from the medicinal plant Schisandra micrantha. This is the first example of an unusual, natural, highly oxidized cycloartane skeleton with a biosynthetically modified eight-membered ring D isolated from the family Schisandraceae.