Hymerhabdrin A (1), a diterpenoid possessing a novel 6/6/5 fused-ring skeleton, together with four known sterols were isolated from an intertidal marine sponge Hymerhabdia sp. Their structures were elucidated by extensive spectroscopic methods, and the relative and absolute configurations of 1 were determined by NOESY analysis and electronic circular dichrosim calculations, respectively. Hymerhabdrin A (1) exhibited significant antifouling activity against Balanus amphitrite larval with LC₅₀ (lethal concentration 50) value of 3.6 μg ml^-1.

中文翻译：

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Hymerhabdrin A，一种新型的二萜类化合物，具有潮间带海绵Hymerhabdia sp。的防污活性。

Hymerhabdrin A（1），一种具有新颖的6/6/5稠环骨架的二萜类化合物，与四种已知固醇一起从潮间带海洋海绵Hymerhabdia sp。分离。通过广泛的光谱学方法阐明了它们的结构，并分别通过NOESY分析和电子圆二色性计算确定了1的相对和绝对构型。Hymerhabdrin A（1）表现出显著防污活性对纹藤壶幼虫与LC ₅₀（致死浓度50）3.6微克毫升值^-1。