Search Results (2)

While tropical regions have traditionally been the focus of studies on natural bioactive products, works published within the last decade demonstrate that cyanobacteria from the Baltic Sea also possess significant biotechnological and pharmaceutical potential. The Baltic Pseudanabaena galeata CCNP1313 previously demonstrated activity against breast cancer cell lines (MCF7 and T47D) and several viruses. In the present study, the cytotoxicity of cellular extract and flash chromatography fractions from the strain were evaluated against a wider panel of cancer cells (A549, C-33A, CaSki, DoTC2, HeLa, PC3, SiHa, and T47D). To gain better insight into the compounds potentially responsible for the observed effects, high-resolution mass spectrometry was combined with bioactivity-based molecular networking. Both the extract and hydrophobic fractions showed strong cytotoxicity, particularly against breast cancer cells and selected cervical cancer cells. While HRMS analyses confirmed the production of previously characterised peptides by CCNP1313 (Pseudanabaena galeata peptides and galeapeptins), neither of them was found to be responsible for the activity. Instead, the molecular networking approach linked the cytotoxicity to specific lipid classes, including diacylglycerols (DAGs) and monogalactosyldiacylglycerols (MGDGs). This study highlights the necessity of integrating traditional methods with advanced bioinformatics for the successful discovery of bioactive natural products, especially when complex samples, such as extract or chromatographically separated fractions, are analysed. Full article

Even cyanobacteria from ecosystems of low biodiversity, such as the Baltic Sea, can constitute a rich source of bioactive metabolites. Potent toxins, enzyme inhibitors, and anticancer and antifungal agents were detected in both bloom-forming species and less commonly occurring cyanobacteria. In previous work on the Baltic Pseudanabaena galeata CCNP1313, the induction of apoptosis in the breast cancer cell line MCF-7 was documented. Here, the activity of the strain was further explored using human dermal fibroblasts, African green monkey kidney, cancer cell lines (T47D, HCT-8, and A549^ACE2/TMPRSS2) and viruses (SARS-CoV-2, HCoV-OC43, and WNV). In the tests, extracts, chromatographic fractions, and the main components of the P. galeata CCNP1313 fractions were used. The LC-MS/MS analyses of the tested samples led to the detection of forty-five peptides. For fourteen of the new peptides, putative structures were proposed based on MS/MS spectra. Although the complex samples (i.e., extracts and chromatographic fractions) showed potent cytotoxic and antiviral activities, the effects of the isolated compounds were minor. The study confirmed the significance of P. galeata CCNP1313 as a source of metabolites with potent activity. It also illustrated the difficulties in assigning the observed biological effects to specific metabolites, especially when they are produced in minute amounts. Full article