Absolute configuration assignment of marine natural products in Brazil

Brazil is one of the most biodiverse countries in the world, with a coastline that stretches over 7,000 km including various marine ecosystems, such as coral reefs, mangroves, and seagrass beds, among other habitats. These diverse environments provide a rich source of compounds, derived from primary or secondary metabolism, which may have countless biological activities. Research on marine natural products (MNP) in Brazil has been ongoing for several decades and led to the discovery of numerous bioactive compounds with potential applications in medicine, agriculture, and cosmetics. These MNP are structurally complex, both from an architectural and stereochemical point of view. However, even with all the well-established techniques for the absolute configuration (AC) assignment, this stage of structural characterization of natural products is still under-explored and remains a challenge. This review presents an overview of natural product chemistry in Brazil, focusing on the stereochemical assignment of marine chiral compounds. The main goals are to describe the techniques employed in the assignments as well as to highlight the importance of choosing the appropriate methods for chiral natural products AC determinations.