NMR- and MS-guided fractionation of an extract of an Okeania sp. marine cyanobacterium, collected from the Red Sea, led to the isolation of four new metabolites, including serinolamides C (1) and D (2) and lyngbyabellins O (3) and P (4), together with the three known substances lyngbyabellins F (5) and G (6) and dolastatin 16 (7). The planar structures of the new compounds were determined using NMR and MS analyses. The absolute configurations of 1 and 2 were determined by Marfey’s analysis of their hydrolysates. The absolute configuration of 3 was ascertained by chiral-phase chromatography of degradation products, while that of 4 was determined by comparison to 3 and 5. The cytotoxic and antifouling activities of these compounds were evaluated using MCF7 breast cancer cells and Amphibalanus amphitrite larvae, respectively. Compounds 3, 4, and 7 exhibited strong antifouling activity, and 3 and 7 were not cytotoxic. A structure–activity relationship was observed for the cytotoxicity of the lyngbyabellins with the presence of a side chain (4 is more active than 3) leading to greater activity. For the antifouling activity, the acyclic form without a side chain (3) was the most active.

中文翻译：

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来自Okeania sp。的Serinolamides和Lyngbyabellins 。从红海收集的蓝细菌

NMR-和MS-引导的提取物的分馏Okeania藻。从红海收集的海洋蓝细菌导致分离出四种新的代谢产物，包括丝脂酰胺化合物C（1）和D（2）和lyngbyabellins O（3）和P（4），以及三种已知的lyngbyabellins F（5）和G（6）和dolastatin 16（7）。使用NMR和MS分析确定了新化合物的平面结构。1和2的绝对构型由Marfey对它们的水解产物的分析确定。绝对配置3由降解产物的手性相色谱法确定，而的4通过比较来确定到3和5。分别使用MCF7乳腺癌细胞和Amphibalanus amphitrite幼虫评估了这些化合物的细胞毒性和抗污垢活性。化合物3，4和7表现出强的防污活性，和3和7不细胞毒性的。存在侧链的情况下，观察到的lyngbyabellins的细胞毒性具有结构-活性关系（4比3更活泼）导致更多的活动。对于防污活性，无侧链的无环形式（3）最为活跃。