Four new diterpenoids alysine A, alysine B, 3-deacetylalysine B and al
ysine C with a novel rearranged neo-clerodane skeleton were isolated f
rom Teucrim alyssifolium. The relative structures were determined by X
-ray analysis and other spectroscopic methods including 1D and 2D NMR
experiments (APT, SINEPT, HETCOR and HMBC).