Three labdane-type diterpenes; 3-oxo-marrubiin and a mixture of two re
lated C-15 epimeric diterpenes based on 9 alpha,13 alpha,15,16-bisepox
y-15-hydroxy-3-oxo-labdan-6 beta,19-olide, in addition to the acylated
flavone apigenin 7-O-[6 ''-O-(p-hydroxy-trans-cinnamoyl)glucoside] we
re isolated and identified from the aerial parts of Leucas neufliseana
. Their structures were established through physical and chemical meth
ods in addition to standard spectroscopic techniques. This is the firs
t report of the isolation of the two epimeric diterpenes from a natura
l source.