Complete 1H and 13C NMR assignments of two new trans‐clerodane diterpenoids from Otostegia limbata

Two new tricyclic trans-clerodane diterpenoids trivially named as ballotenic acid A (1) and ballodiolic acid A (2) have been isolated from ethyl acetate fraction of Otostegia limbata. The structure assignments are based on 1H and 13C NMR spectra, 2D NMR (HMQC, HMBC, COSY, NOESY and NOE) techniques and comparison with the literature data. Copyright © 2007 John Wiley & Sons, Ltd.