Isoxazoline alkaloids, brominated

Scheme 21 Wound-activated bioconversion of brominated isoxazoline alkaloids by the sponge Aplysina aerophoba...

Thompson et al. have investigated the ecological role of the brominated isoxazoline alkaloids, aerothionin (Structure 2.84) and homoaerothionin (Structure 2.89), in Californian specimens of A. fistularis.134 139 The alkaloids caused behavioral modification in marine invertebrates, were toxic to dorid nudibranchs other than one specialized feeder, inhibited the settlement and/or metamorphosis of invertebrate larvae, and were strongly antimicrobial and cytotoxic. Sponges exuded significantly more of these two alkaloids when wounded,155 and, consistent with their defensive role, the metabolites were found to be localized in spherulous cells close to the aquiferous exhalant canals.156... 

Scheme 1 Wound-induced conversion of brominated isoxazoline alkaloids in Aplysina aerophoba.99,102...

---