Mycosporine-like amino acids, brominated and sulphated phenols: Suitable chemotaxonomic markers for the reassessment of classification of Bostrychia calliptera (Ceramiales, Rhodophyta)

Red algae (Rhodophyta) are primarily found in marine habitats around the world and they have been a prolific source of structurally diverse natural products. Among them the genus Bostrychia (Ceramiales, Rhodomelaceae) consists of approximately 40 taxonomically accepted species, and some, e. g., B. tenella, B. radicans, B. moritziana, B. simpliciuscula and B. intricate, include cryptic species. DNA sequence data show three genetic lineages within Bostrychia calliptera, another polyphyletic species requiring further taxonomic investigation. In an attempt to examine whether there are differences in the metabolite pattern that support the re-circumscription of the species and to uncover biogeographic patterns, phytochemical profiling of those samples used for DNA sequencing was conducted. This investigation revealed clearly three different chemotypes, corresponding to the lineages of the published molecular analysis results. The first lineage had a distinct and recognizably different phytochemical profile in contrast to the second and the third lineage which shared some similarities. Still, variations in the pattern of their phenolic compounds allowed a clear discrimination between the second and third lineage, too. The most important marker substances were isolated and their structures elucidated resulting in the characterization of four undescribed phenols. The isolated substances from B. calliptera are considered as suitable chemotaxonomic markers within this polyphyletic group.