**2. Marine biodiversity and chemodiversity**

More than 70% of the Earth's surface are oceans and seas. It is not surprising to affirm that the marine environment is characterized by an important biodiversity in comparison to terrestrial organisms. In 2010, 230,000 marine species were listed [12]. Consequently, with the increase of biological space (biodiversity), more novel metabolites (high chemodiversity), involved in ecological interactions, are produced in order to ensure easy adaptation of the species [13, 14]. Furthermore, the chemodiversity of the marine ecosystem has no equivalent in terrestrial environment. The large groups of the sea organisms, such as red algae and soft corals, are known to produce a great variety of quite unique secondary metabolites, such as highly halogenated terpenes, definitely due to the high halogen concentration of the sea water, and acetogenins from *Laurencia* (Rhodophyta) [15, 16], toxic polyketide from sponges [17], and prostaglandins from the gorgonian corals [18, 19].
