Intraspecific variation in the terpene profiles of Dodonaea viscosa

Natural products isolation studies were performed on Dodonaea viscosa plant individuals sampled across seven different populations, which revealed considerable intraspecific variation in the terpene profiles across D. viscosa. In total, 14 ent-labdane diterpenoids (seven of which are previously unreported), four ent-kauranes (one which is previously unreported), one rare norhopene, and two previously unreported monoterpenoid wax esters were isolated. Exceedingly few terpene wax esters have been reported in Nature and the isolation of these unusual secondary metabolites is particularly notable for this reason. In each case, the proposed structures were elucidated employing various standard one- and two-dimensional NMR (¹H, ¹³C, NOESY, COSY, HSQC, HMBC) spectroscopic techniques and complemented by IR spectroscopy, mass spectrometry, and polarimetry, where appropriate. Synthetic derivatization and X-ray crystallographic analysis were also employed to further support or secure structural assignments.