Marine sponges are important members of reef ecosystems, as they play ecological roles that are essential for the health of the reef. From a chemical perspective, sponges have been widely studied,... Show moreMarine sponges are important members of reef ecosystems, as they play ecological roles that are essential for the health of the reef. From a chemical perspective, sponges have been widely studied, showing great chemical diversity with biological activity, although this chemical diversity can often not be linked to for instance variation in environmental conditions experienced by sponges. Metabolomics, with its holistic overview of the metabolites present in samples, has provided new tools to gain insight into the function of metabolites in the intricate relationship between sponges and their environment. Among sponges, giant barrel sponges have stood out for their predominance in many reefs, their longevity and the fact that they are widely spread across oceans. this thesis showed how environmental, genetic and biological factors individually or as a result of their interaction can influence the metabolome of giant barrel sponges. This is only the first step towards a better understanding of the role that chemical compounds play in interactions between sponges and the surrounding environment. The advances in this field will rely, among others, on the development of technologies that would allow real time measurement of the metabolome and the study of the interaction between the metabolome and other omics. Show less
Natural deep eutectic solvents (NADES) made mainly with abundant primary metabolites are being increasingly applied in green chemistry. The advantages of NADES as green solvents have led to their... Show moreNatural deep eutectic solvents (NADES) made mainly with abundant primary metabolites are being increasingly applied in green chemistry. The advantages of NADES as green solvents have led to their use in novel green products for the food, cosmetics and pharma markets. However, one of the main difficulties encountered in the development of novel products and their quality control arises from their low vapour pressure and high viscosity. These features create the need for the development of new analytical methods suited to this type of sample. In this study, such a method was developed and applied to analyse the efficiency of a diverse set of NADES for the extraction of compounds of interest from two model plants, Ginkgo biloba and Panax ginseng. The method uses high-performance thin-layer chromatography (HPTLC) coupled with multivariate data analysis (MVDA). It was successfully applied to the comparative quali- and quantitative analysis of very chemically diverse metabolites (e.g., phenolics, terpenoids, phenolic acids and saponins) that are present in the extracts obtained from the plants using six different NADES. The composition of each NADES was a combination of two or three compounds mixed in defined molar ratios; malic acid-choline chloride (1:1), malic acid-glucose (1:1), choline chloride-glucose (5:2), malic acid-proline (1:1), glucose-fructose-sucrose (1:1:1) and glycerol-proline-sucrose (9:4:1). Of these mixtures, malic acid-choline chloride (1:1) and glycerol-proline-sucrose (1:1:1) for G. biloba leaves, and malic acid-choline chloride (1:1) and malic acid-glucose (1:1) for P. ginseng leaves and stems showed the highest yields of the target compounds. Interestingly, none of the NADES extracted ginkgolic acids as much as the conventional organic solvents. As these compounds are considered to be toxic, the fact that these NADES produce virtually ginkgolic acid-free extracts is extremely useful. The effect of adding different volumes of water to the most efficient NADES was also evaluated and the results revealed that there is a great influence exerted by the water content, with maximum yields of ginkgolides, phenolics and ginsenosides being obtained with approximately 20% water (w/w). Show less
