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SUMMARY: Okinawan coasts are a rich source of biodiversity, including of filamentous cyanobacteria, owing to their habitat diversity created by coral reefs. Along the coastlines of Okinawa, several undescribed species, including those from Neolyngbya, remain unexplored. In this study, two undescribed cyanobacterial species with morphological resemblance to Neolyngbya were identified using a polyphasic approach. Both taxa had morphological features similar to known species of Neolyngbya; however, the cell size and thallus shape were different. Phylogenetic analyses of the 16S rRNA gene and the 16S‐23S rRNA internal transcribed spacer (ITS) region showed that the two new species formed a highly supported independent subclade within Neolyngbya. Accordingly, three informative domains of the ITS region (D1‐D1′, Box B and V3) also presented distinct secondary structures compared to previously described species of Neolyngbya, both in structure form and configuration. Overall, analyses of morphology and phylogeny of the 16S rRNA gene and the 16S‐23S rRNA ITS region, as well as the secondary structures of ITS region, supported the proposal of two new species within Neolyngbya. Herein, we propose N. intertidalis sp. nov. and N. latusa sp. nov. as new members of Neolyngbya under the provisions of the International Code of Nomenclature for Algae, Fungi and Plants (ICN). [ABSTRACT FROM AUTHOR]

Metabolomics can be used to study complex mixtures of natural products, or secondary metabolites, for many different purposes. One productive application of metabolomics that has emerged in recent years is the guiding direction for isolating molecules with structural novelty through analysis of untargeted LC-MS/MS data. The metabolomics-driven investigation and bioassay-guided fractionation of a biomass assemblage from the South China Sea dominated by a marine filamentous cyanobacteria, cf. Neolyngbya sp., has led to the discovery of a natural product in this study, wenchangamide A (1). Wenchangamide A was found to concentration-dependently cause fast-onset apoptosis in HCT116 human colon cancer cells in vitro (24 h IC50 = 38 μM). Untargeted metabolomics, by way of MS/MS molecular networking, was used further to generate a structural proposal for a new natural product analogue of 1, here coined wenchangamide B, which was present in the organic extract and bioactive sub-fractions of the biomass examined. The wenchangamides are of interest for anticancer drug discovery, and the characterization of these molecules will facilitate the future discovery of related natural products and development of synthetic analogues.

Abstract Marine filamentous cyanobacteria are sources of biologically active secondary metabolites with potential biotechnological application. Despite the extension and environmental variety of the Brazilian coast, floristic surveys of filamentous cyanobacteria are scarce. Studies on their biotechnological potential are even more limited. In this work, we sampled Neolyngbya (Oscillatoriaceae) populations along the Brazilian coast and evaluated the antimicrobial, antioxidant, and cytotoxic activities of their organic extracts. We also assessed the strains' genetic potential for production of cyanotoxins. The strains were cultivated in SWBG-11 medium. Extraction of biomass was carried out with methanol, ethanol, and acetic acid. Antimicrobial (against seven bacterial strains and the yeast Candida albicans), antioxidant (DPPH and ABTS radicals), and cytotoxic (brine shrimp) potential were evaluated. PCR reactions were performed to analyze the genetic potential for the production of microcystin, saxitoxin, and cylindrospermopsin. Brazilian marine filamentous cyanobacteria presented relevant antimicrobial capacity. Seven extracts from four Neolyngbya strains inhibited growth of almost all bacteria, while nine extracts from four strains inhibited C. albicans , with a minimum inhibitory concentration (MIC) range from 2.5 to 10.0 mg·mL−1. Methanolic extracts presented the greatest antioxidant potential for both DPPH and ABTS radicals, ranging from 50.0 to 98.3% at a concentration of 10 mg·mL−1. Cytotoxicity assays showed a LC 50 ranging from 0.8 to 6.6 mg·mL−1. We detected toxic genotypes in eight of the analyzed strains, in which the most frequent gene clusters were mcyG (microcystin) and cyrJ (cylindrospermopsin). All Neolyngbya strains screened in this study have potential for biotechnological application, which highlights the economical and pharmacological importance of studying this underestimated biodiversity in tropical areas. Highlights • Neolyngbya species from the Brazilian coast present biotechnological application. • Brazilian cyanobacteria show high antioxidant potential and antimicrobial activity. • Marine genus Neolyngbya exhibited low cytotoxicity of secondary metabolites. • Toxic genotypes efficiently recognized by detecting cyanotoxin genes. • Strains of Neolyngbya can be used for bioprospection of new metabolites. [ABSTRACT FROM AUTHOR]

Metabolomics can be used to study complex mixtures of natural products, or secondary metabolites, for many different purposes. One productive application of metabolomics that has emerged in recent years is the guiding direction for isolating molecules with structural novelty through analysis of untargeted LC-MS/MS data. The metabolomics-driven investigation and bioassay-guided fractionation of a biomass assemblage from the South China Sea dominated by a marine filamentous cyanobacteria, cf. Neolyngbya sp., has led to the discovery of a natural product in this study, wenchangamide A (1). Wenchangamide A was found to concentration-dependently cause fast-onset apoptosis in HCT116 human colon cancer cells in vitro (24 h IC50 = 38 μM). Untargeted metabolomics, by way of MS/MS molecular networking, was used further to generate a structural proposal for a new natural product analogue of 1, here coined wenchangamide B, which was present in the organic extract and bioactive sub-fractions of the biomass examined. The wenchangamides are of interest for anticancer drug discovery, and the characterization of these molecules will facilitate the future discovery of related natural products and development of synthetic analogues. [ABSTRACT FROM AUTHOR]