Aplysia kurodai metabolites

While little biosynthetic information is available, it has been suggested [38] that 25 and 26 may be formed from AA (24) and EPA (14) via a cyclization mechanism (Scheme 3) similar to that which forms trans-cyclopropyl-containing diol 28 upon treatment of linoleic acid with performic acid [40]. An alternative biogenetic mechanism (Scheme 4), based upon that proposed for the structurally related red algal metabolites constanolactone A and B [41], would involve the formation and opening of an allylic epoxide intermediate created as a result of a 15-/ -LPO acting on either AA or EPA. Related compounds have been isolated from the coral Plexaura homomalla and the mollusc Aplysia kurodai (see below). 

The brominated alkaloid neoaplaminone sulfate (196) was isolated from the sea hare Aplysia kurodai and its structure was determined by spectral and chemical methods [186]. A. kurodai obtains most, if not all of its metabolites from the red algae on which it feeds [10]. 

Here again, there has been little work on the metabolites of fungi associated with mollusks. Isolated from the sea hare, Aplysia kurodai, the fungus Periconia byssoides produces in culture two cytotoxic derivatives, pericosines A and H, and four trilactones, macrosphelides E-H, which are devoid of activity (Numata et al, 1997b). The cytotoxicity of pericosines A and B on P-388 is notable with... 

Ojika, M., Yoshida, Y., Nakayama, Y, and Yamada, K. (1990) Aplydilactone, a novel fatty acid metabolite from the marine mollusc Aplysia kurodai. Tetrahedron Lett., 31, 4907-1910. 

---