# Brown Algae from San Andres Island, Southwest Caribbean: A Nuclear Magnetic Resonance Spectroscopy–Metabolomic Study

## TL;DR

This study uses NMR spectroscopy to analyze the metabolites of brown algae from San Andrés Island, revealing species-specific metabolic patterns and environmental influences.

## Contribution

The study provides new insights into the metabolic diversity of brown algae in the SW Caribbean using NMR-based metabolomics.

## Key findings

- S. zonale and C. crispatus were distinguished by their unique metabolite profiles, including meroditerpenes and diterpenes.
- Metabolic differences in S. zonale were linked to growth substrates, such as rocky bottoms versus dead coral.
- Temporal lipid variations were observed in P. gymnospora, and juvenile Dictyota spp. showed simpler metabolic signatures.

## Abstract

Background: Brown algae from the order Dictyotales are known to produce specialized metabolites with a wide array of biological activities. Studying these compounds is important for understanding their ecological roles, exploring biomedical potential and developing biotechnological applications. Methods: To evaluate the metabolic diversity of brown algae from the shallow habitats of the northern region of San Andrés Island (Colombia, SW Caribbean), a metabolic profiling approach was employed, based on 1H-NMR spectra taken from organic extracts. Four sampling expeditions were conducted to collect the most abundant species, taking into account the taxonomic identity, growth substrate and collection date. Results: Five species were found and identified as Canistrocarpus crispatus, Stypopodium zonale, Dictyopteris delicatula, Padina gymnospora and Dictyota spp. Multivariate analyses applied to these spectra revealed that S. zonale and C. crispatus differentiated from the other samples mainly due to the signals for meroditerpenes and diterpenes, respectively. S. zonale had differential metabolic production observed when comparing algae collected in rocky bottoms with thalli growing on dead coral. This difference was attributed to changes in concentrations of the meroditerpene atomaric acid (1). Meanwhile, the major metabolite found in C. crispatus samples was dictyol B acetate (2). Conclusions: NMR metabolomics of San Andrés brown algae differentiated species based on lipid content and metabolic complexity. Notably, prenylated-guaiane diterpenes characterized C. crispatus, and meroditerpenoid concentrations varied in S. zonale. Temporal lipid variations were observed in P. gymnospora, while juvenile Dictyota spp. presented a less complex metabolic signature.