Novel terpenoids from the Sea Hare <i>Aplysia punctata</i>

Abstract

The structures of 23 compounds isolated from the sea hare Aplysia punctata have been determined by spectroscopic means. These include four new diterpenes (1–4): 1, neopargueroldione, is a tricyclic diterpene featuring a novel octane-1,5-dione A ring; 2 is deacetylparguerol; 3, punctatene acetate, shares the same [2:2:1] bicyclic system as dactylomelol from A. dactylomela; and 4, punctatol, has the same skeleton as laurencianol of algal origin. Diastereomeric sesquiterpenes 5 and 6 are similar to some compounds of algal origin, as is 7, perforatol, which shares the same carbon framework as perforatone from Laurentia perforata. In addition we have isolated 16 known compounds comprising 12 sesquiterpenes: perforenone, laurene, α-bromocuparane, α-isobromocuparane, laurinterol, debromoallolaurinterol, laurenisol, isofiliformin, obtusenol, β-snyderol, a dibromochamigrane, a friedosnyderane, two diterpenes: isoconncindiol and parguerol, and two C-15 acetogenins: laurenyne and laurencenyne. These known compounds have been reported previously either from other Aplysia species or from Laurencia species.Key words: Aplysia punctata, terpenoids, Sea Hare constituents.