Castelo-Branco Raquel, Pereira João P, Freitas Sara, Preto Marco, Vieira Ana R, Morais João, Leão Pedro N
Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Avenida General Norton de Matos, s/n4450-208Matosinhos, Portugal.
J Nat Prod. 2025 Jan 24;88(1):86-93. doi: 10.1021/acs.jnatprod.4c01063. Epub 2024 Dec 24.
Genome mining has emerged as an important tool for the discovery of natural products and is particularly effective for the swift identification of ribosomally synthesized and post-translationally modified peptides (RiPPs). Among RiPPs, cyanobactins have gained attention due to their diverse structures and bioactive properties. Here, we explored the Microcoleaceae cyanobacterium LEGE 16532 strain and identified the biosynthetic gene cluster (BGC), which was predicted to encode cyanobactin-like molecules. This led to the detection of 11 macrocyclic cyanobactins, the monchicamides, some of which feature mono- or diprenylation. One of the compounds was isolated, monchicamides I (), and its planar structure was established by LC-HRESIMS/MS data as well as 1D and 2D NMR spectroscopy, confirming forward O-prenylation in Tyr. In addition, the absolute configuration of compound was determined by Marfey's method and chiral-phase HPLC. The structures of the additional cyanobactins were proposed from MS/MS data analysis. The bioactivity profile of the isolated compound was also evaluated, but no cytotoxic, antimicrobial, or antiamoebic activity was observed.
基因组挖掘已成为发现天然产物的重要工具，对于快速鉴定核糖体合成及翻译后修饰肽（RiPPs）尤为有效。在RiPPs中，蓝细菌素因其多样的结构和生物活性特性而受到关注。在此，我们对微鞘藻科蓝细菌LEGE 16532菌株进行了探索，并鉴定出生物合成基因簇（BGC），该基因簇预计编码类似蓝细菌素的分子。这导致检测到11种大环蓝细菌素，即蒙奇卡胺，其中一些具有单异戊烯基化或双异戊烯基化特征。分离出其中一种化合物，即蒙奇卡胺I（），其平面结构通过液相色谱 - 高分辨电喷雾电离质谱/质谱数据以及一维和二维核磁共振光谱确定，证实了酪氨酸上的正向O - 异戊烯基化。此外，化合物的绝对构型通过马尔菲方法和手性相高效液相色谱法确定。通过串联质谱数据分析推测了其他蓝细菌素的结构。还评估了分离出的化合物的生物活性谱，但未观察到细胞毒性、抗菌或抗阿米巴活性。
