Further studies on the constituents of the seeds of Alpinia zerumbet a
fforded two new labdane-type diterpenes, zerumin A and zerumin B, toge
ther with two known compounds, (E)-15,16-bisnorlabda-8(17), 11-diene-1
3-one and coronarin E. Their structures were elucidated by spectroscop
ic techniques.