Antitumor potential of natural products from Mediterranean ascidians

Abstract

Ascidians, invertebrates belonging to the subphylum Urochordata (Tunicata), are renowned for their great chemical diversity, and during the last 25 years, they have been shown to produce an array of cytotoxic molecules. Among the first six marinederived compounds that have reached clinical trials as antitumor agents, three are derived from ascidians, as evidence of the high potential of these organisms as a new source of antitumor compounds. Reported in this communication are some recent results on the chemistry of Mediterranean ascidians; a number of new molecules with different structural features but all endowed with antiproliferative or cytotoxic activity are discussed. These results strongly evidence the highly significant role that Mediterranean ascidians natural products could play in anticancer drug discovery and development process.

Crucigasterins A–E, antimicrobial amino alcohols from the Mediterranean colonial ascidian Pseudodistoma crucigaster

“…In the 13 C NMR spectrum, carbon signals at d 18.5 (q, C-1), 46.7 (d, C-2) and 75.9 (d, C-3) confirmed this assignment. The expected signals due to two acetyl residues esterifying both amino and hydroxyl groups were observed in the carbon and proton spectra [d C 20.9 (q, OeCOCH 3 ), 23 Table 2). The relative configuration of the chiral centres C-2 and C-3 was deduced by analysing a series of NOE difference experiments recorded on the corresponding oxazolidinone derivative 8, which was obtained by the reaction of 2 with 1,1 0 -carbonyldiimidazole, according to the procedure applied for related molecules.…”

“…22 These molecules are closely related to sphingolipids and show interesting bioactivities as antibiotics, 4,5,14,21 antimycotics 4,18,20a,b,21 and as antitumour agents. 4,15,19,23 In this paper, we describe the structural elucidation of five novel unsaturated amino alcohols, crucigasterins AeE (2e6), isolated along with related known compound 7, previously reported from South African Pseudodistoma sp. 5 These molecules, which exhibit different carbon chain length and oxidation degree and are all characterised by the threo-configuration of the amino alcohol moiety, in contrast with the erythro-stereochemistry of previously reported crucigasterins, 4 have been characterised as diacetyl derivatives 2ae6a.…”

Bioprospection of Cytotoxic Compounds in Fungal Strains Recovered from Sediments of the Brazilian Coast

“…Cytotoxicity is the most expressive biological activity of the extracts from marine sources, and the number of compounds under clinical investigation confirms the potential of the marine natural products for anticancer chemotherapy [5].…”

Cytotoxic compounds from the marine-derived fungusAspergillussp. recovered from the sediments of the Brazilian coast

“…When compared with that of terrestrial sources, the bioprospection of marine sources in search of novel and bioactive compounds is still incipient, as only 14% of all known natural products are of marine origin (Menna 2009;Blunt et al 2011). Cytotoxicity in the extracts of organisms from marine environments is one of the most expressive biological activities, and surpasses those of terrestrial origin.…”

“…Cytotoxicity in the extracts of organisms from marine environments is one of the most expressive biological activities, and surpasses those of terrestrial origin. When considering the list of the natural compounds under clinical investigation, anticancer chemotherapy is suggested as the stronghold of marine natural products (Menna 2009). On the course of our ongoing research program regarding the identification of new antitumour compounds from the Brazilian marine biodiversity (Montenegro et al 2012), we report, herein, the bioprospection of cytotoxic compounds from the marine-derived fungus Aspergillus sp.…”