Mono-, Bi-, and Triphenanthrenes from the Tubers of <i>Cremastra </i><i>a</i><i>ppendiculata</i>

Six newphenanthrene derivatives, including three monophenanthrenes (<b>1</b>−<b>3</b>), two biphenanthrenes (<b>4</b> and <b>5</b>), and a triphenanthrene (<b>6</b>), have been isolated from an ethanolic extract of the tubers of <i>Cremastra </i><i>appendiculata</i>. Using spectroscopic methods, the structures of compounds <b>1</b>−<b>6</b> were determined as 1-hydroxy-4,7-dimethoxy-1-(2-oxopropyl)-1<i>H</i>-phenanthren-2-one (<b>1</b>), 1,7-dihydroxy-4-methoxy-1-(2-oxopropyl)-1<i>H</i>-phenanthren-2-one (<b>2</b>), 2-hydroxy-4,7-dimethoxyphenanthrene (<b>3</b>), 2,7,2‘-trihydroxy-4,4‘,7‘-trimethoxy-1,1‘-biphenanthrene (<b>4</b>), 2,2‘-dihydroxy-4,7,4‘,7‘-tetramethoxy-1,1‘-biphenanthrene (<b>5</b>), and 2,7,2‘,7‘,2‘ ‘-pentahydroxy-4,4‘,4‘ ‘,7‘ ‘-tetramethoxy-1,8,1‘,1‘ ‘-triphenanthrene (<b>6</b>), respectively. Compounds <b>1</b>−<b>6</b> and two known compounds, cirrhopetalanthin (<b>7</b>) and flavanthrinin (<b>8</b>), obtained previously from this plant, were evaluated against six human cancer cells and a normal cell line.