RESUMO
The marine sponge Aka coralliphaga is a rich source of biologically active and structurally interesting meroterpenoids. Inspired by these natural products, we have used biosynthetic speculation to devise biomimetic syntheses of siphonodictyal B, liphagal and corallidictyals A-D from sclareolide. This work resulted in the development of new cascade reactions in the synthesis of liphagal, the reassignment of the structure of siphonodictyal B, and the realisation that corallidictyals A and B are possibly isolation artefacts.
Assuntos
Produtos Biológicos/química , Hidroquinonas/síntese química , Poríferos/química , Sesquiterpenos/síntese química , Terpenos/síntese química , Animais , Produtos Biológicos/síntese química , Biomimética , Ciclização , Diterpenos/química , Hidroquinonas/química , Oxirredução , Poríferos/metabolismo , Sesquiterpenos/química , Terpenos/químicaRESUMO
The naphterpins and marinones are naphthoquinone meroterpenoids with an unusual aromatic oxidation pattern that is biosynthesized from 1,3,6,8-tetrahydroxynaphthalene (THN). We propose that cryptic halogenation of THN derivatives by vanadium-dependent chloroperoxidase (VCPO) enzymes is key to this biosynthetic pathway, despite the absence of chlorine in these natural products. This speculation inspired a total synthesis to mimic the naphterpin/marinone biosynthetic pathway. In validation of this biogenetic hypothesis, two VCPOs were discovered that interconvert several of the proposed biosynthetic intermediates.