Caulerpenyne-Amine Reacting System as a Model for in vivo Interactions of Ecotoxicologically Relevant Sesquiterpenoids of the mediterranean-adapted tropical green seaweed caulerpa taxifolia
✍ Scribed by Antonio Guerriero; Daniela Depentori; Michele D'Ambrosio; Francesco Pietra
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- German
- Weight
- 525 KB
- Volume
- 78
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Abstract
Caulerpenyne (1), the most abundant of the ecotoxicologically relevant sesquiterpenoids of the Mediterranean‐adapted tropical green seaweed Caulerpa taxifolia, was found to react with Et~3~N or pyridine in MeOH by initial deprotection of C(1)HO to give oxytoxin 1 (2a), previously isolated from the sacoglossan mollusc Oxynoe olivacea. With BuNH~2~, without any precaution to exclude light, 1 gave the series of racemic 3 and 4, and achiral (4__E__,6__E__)‐5, (4__E__,6__Z__)‐5, (4__Z__,6__E__)‐5, and (4__Z__,6__Z__)‐5 pyrrole compounds, corresponding to formal C(4) substitution, 4,5‐β‐elimination, and (E/Z)‐isomerization at the C(4)C(5) and C(6)C(7) bonds. Changing to CDCl~3~ as solvent in the dark, 1 gave cleanly, via 2a as an intermediate, 3 and (4__E__,6__E__)‐5. The latter proved to be prone to (E/Z)‐photoisomerization. Under standard acetylation conditions, 3 gave (4__E__,6__E__)‐5 via acetamide 7 as an intermediate. Particular notice is warranted by selective deprotection of 1 at C(1), mimicking enzyme reactions, and unprecedented formation of pyrrole compounds from freely‐rotating, protected 1,4‐dialdehyde systems.