Mikanin-3-O-sulfate (1), in the form of its potassium salt, together with m
ikanin (2) and alpinetin (3) were isolated from Mikania micrantha. The crys
tal structures of K(1). CH3OH, 2 and 3 .H2O were established by Xray crysta
llography. The potassium ions in K(1). CH3OH are bridged by O5, O7 and O8 t
o form a chain of face-sharing KO8 coordination polyhedra, from which the a
glycon units are outstretched to form a polymeric molecular column. Adjacen
t molecular columns are linked by pi-pi stacking between parallel, intercal
ating aglycon units to form layers matching the (10 (1) over bar) family of
planes, which are further interconnected into a three-dimensional supramol
ecular assembly. Sulfation at 3-OH induced better co-planarity and conjugat
ion of the rings.