Intra-population variability in terpene metabolism of the Antarctic opisthobranch mollusc Austrodoris kerguelenensis

Austrodoris kerguelenensis is an Antarctic marine mollusc possessing a wide array of deterrent terpene glycerides. The occurrence of these compounds has been studied in individuals of a sample of 21 specimens from two different geographical sites. NMR spectroscopy and liquid chromatography (LC)-MS/MS analysis revealed seven glycerides (1-7) based on four diterpene skeletons in these animals. Among the new compounds 4-7, the glyceride 7 shows a rare 9-epi-labdane skeleton. The interindividual variability of these compounds indicates several chemotypes in the same population and suggests the presence of terpene synthase variants involved in the biosynthesis of these defensive molecules.