Comparative analysis of the corps en cerise in several species of Laurencia (Ceramiales, Rhodophyta) from the Atlantic Ocean

Abstract

Different species of Laurencia have proven to be a rich source of natural products yielding interesting bioactive halogenated secondary metabolites, such as terpenoids and acetogenins. It is shown that such compounds are accumulated in the spherical, reniform to claviform refractive inclusions called corps en cerise (CC), which are intensively osmiophilic and located mainly in the cortical cells of the thalli and also in trichoblast cells. Up to now, it was believed that CC were present only in these two kinds of cells. Recently, however, a species of Laurencia, L. marilzae, with CC in all cells of the thallus, i.e., cortical, medullary, including the pericentral and axial cells, as well as in the trichoblasts, was described from the Canary Islands, and subsequently also reported to Brazil and Mexico. Within the Laurencia complex, only Laurencia species produce CC. Since the species of Laurencia are targets of interest for the prospection of bioactive substances due to their potential antibacterial, antifungal, anticholinesterasic, antileishmanial, cytotoxic, and antioxidant activities, the present paper carries out a comparative analysis of the corps en cerise in several species of Laurencia from the Atlantic Ocean to obtain basic information that can support natural product bioprospection projects. Our results show that the number and size of the CC are constant within a species, independent of the geographical distribution, corroborating their use for taxonomical purposes to differentiate groups of species that present a lower number from those that have a higher number. In this regard, there was a tendency for the number of CC to be higher in some species of Laurencia from the Canary Islands. The presence of CC can also be used to distinguish species in which these organelles are present in all cells of the thallus from those in which CC are restricted to the cortical cells. Among the species analyzed, L. viridis displayed the most varied secondary metabolites composition, such as sesquiterpenes, diterpenes, triterpenes, all of which showed potent antiviral, cytotoxic, and antitumoral activities, including protein phosphatase type 2A (PP2A) inhibitory effects.

The Laurencia Paradox: An Endless Source of Chemodiversity

“…In fresh material of some species, refringent intracellular "corps en cerise" with discoid to spheroid inclusions are present in the cortical and trichoblast cells [15]. The cortical cells contain photosynthetic pigments arranged in the thylakoids, while other internal cells are colorless [34].…”

“…These organelles occur as intracellular membrane-bound vesicles in trichoblasts and in the outermost cortical cells and have a spherical, reniform to claviform shape [34]. The cellular distribution of halogenated compounds has been demonstrated by fluorescence microscopy that showed them to be stored mainly in the "corps en cerise" and to a lesser degree in vesicles found along the cytoplasm and within the chloroplasts [59].…”

“…Furthermore, a significant number of Laurencia sesquiterpenes including (-)-(10R)-bromo-α-chamigrene (1) [81], laurecomin C (2) [84], 7 [84], laurokamin C (12) [79], 10-bromo-9-hydroxy-α-chamigrene (14) [81], dendroidiol (34) [146], laurecomin B (37) [84], 10-bromo-β-chamigren-8-ol (41) [152,275], 44 [62,155] 10-hydroxy-kahukuene B (633) [74], aplysiadiol (638) [187], and (E)-phytol (641) [342] have been evaluated for their antibacterial and antifungal properties.…”

Progress in the Chemistry of Organic Natural Products 102

“…In turn, skin contact induces within 2-3 h the formation of an erythema that can persist for well over 24 h, but which if the exposed area is limited, can be soothed by topical treatment with local anesthetics and ice blocks [34], or with a solution of a polyamphoteric detergent [35]. Accidental eye contact is characterized by massive lacrimation and acute pain, and may require hospital treatment to be managed correctly.…”

“…Accidental eye contact is characterized by massive lacrimation and acute pain, and may require hospital treatment to be managed correctly. Based on observations done with I3A, the inflammatory response to ingenoids is transient and resolves spontaneously without scarring within 2-4 weeks, during which topical treatment with corticosteroids may be recommended to control pain and inflammation [34]. Hospitalization might, however, be necessary in case of the accidental contamination of a large skin area [34].…”