Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616, Singapore.
Mar Drugs. 2021 Sep 28;19(10):548. doi: 10.3390/md19100548.
Three new cyanobactins, trikoramides B ()-D (), have been isolated from the marine cyanobacterium, , following a preliminary bioassay-guided isolation of the two most active polar fractions based on the brine shrimp toxicity assay. These new cyanobactins are new analogues of the previously reported cytotoxic trikoramide A () with differences mainly in the -prenylated cyclotryptophan unit. Their planar structures were elucidated from their 1D and 2D NMR spectral data in combination with the HRMS/MS data. Marfey's method, 2D NOESY NMR spectroscopic and ECD spectra analyses were used to determine the absolute stereochemistry of trikoramides B ()-D (). Trikoramides B () and D () exhibited cytotoxicity against MOLT-4 acute lymphoblastic leukemia cell line with IC values of 5.2 µM and 4.7 µM, respectively. Compounds and were also evaluated for their quorum-sensing inhibitory assay based on the PAO1 and bioreporter strains. Although trikoramide B () exhibited weak quorum-sensing inhibitory activity, the Br-containing trikoramide D () exhibited moderate to significant dose-dependent quorum-sensing inhibitory activities against PAO1 and bioreporter strains with IC values of 19.6 µM and 7.3 µM, respectively.
从海洋蓝藻中分离得到三种新的蓝藻毒素，即 trikoramides B()-D()，这是基于卤虫毒性测定对两种最活跃的极性部分进行初步生物测定指导分离的结果。这些新的蓝藻毒素是先前报道的细胞毒性 trikoramide A()的新类似物，主要区别在于 -prenylated cyclotryptophan 单元。它们的平面结构通过 1D 和 2D NMR 光谱数据与 HRMS/MS 数据相结合来阐明。Marfey 法、2D NOESY NMR 光谱和 ECD 光谱分析用于确定 trikoramides B()-D()的绝对立体化学。Trikoramides B()和 D()对 MOLT-4 急性淋巴细胞白血病细胞系表现出细胞毒性，IC 值分别为 5.2 μM 和 4.7 μM。和 还基于 PAO1 和生物报告菌株进行了群体感应抑制测定。尽管 trikoramide B()表现出微弱的群体感应抑制活性，但含 Br 的 trikoramide D()对 PAO1 和生物报告菌株表现出中等至显著的剂量依赖性群体感应抑制活性，IC 值分别为 19.6 μM 和 7.3 μM。
