Cytotoxic Compounds of Two Demosponges (Aplysina aerophoba and Spongia sp.) from the Aegean Sea

Abstract

The class of demosponges is the biggest and most diverse of all described sponge species and it is reported to produce a plethora of chemically different metabolites with interesting biological activities. The focus of the present study was to investigate the chemical composition of two Mediterranean demosponges, targeting their brominated compounds and prenylated hydroquinones, compounds with interesting cytotoxic and anti-microbial properties. In order to gain a deeper insight into the chemical diversity of their metabolites and their activities, 20 pure secondary metabolites including new natural products were isolated from two different species (Aplysina aerophoba and Spongia sp.) using various chromatographic techniques. Their structures were confirmed by NMR and HRMS, revealing molecules with various chemical scaffolds, mainly prenylated hydroquinones from Spongia sp. and halogenated compounds from Aplysina aerophoba, including 5 novel natural products. The isolated compounds were investigated for their cytotoxic properties using 9 different cell lines, and especially one compound, 2,6-dibromo-4-hydroxy-4-methoxycarbonylmethylcyclohexa-2,5-dien-1-one showed good activities in all tested models.

Application of Networking Approaches to Assess the Chemical Diversity, Biogeography, and Pharmaceutical Potential of Verongiida Natural Products

“…This represents a comprehensive list of all secondary metabolites isolated from Verongiida sponges within the period from 1960 to May 2020. It is important to note that since May 2020 to August 2021, a further 7 papers have been published concerning secondary metabolites from this order that were not included in this analysis [ 176 , 177 , 178 , 179 , 180 , 181 , 182 ]. A full reference list can be found in Supporting Information S1 .…”

Marine natural products

“…419 Originally an ascidian-derived compound, the structure of etzionin 981 has been revised following its re-isolation along with related diketopiperazines clioetzionins A 982 and B 983 from Cliona celata. 420 An unusual fused g-lactam 984 was reported from Aplysina aerophoba, 421 while new hydantoin-containing alkaloids 985-988 were obtained from Aaptos aaptos and Hemimycale sponges. 414,422 Thorectandrin A 989 is a brominated tryptophan-derived alkaloid isolated from Thorectandra choanoides, collected in the Great Australian Bight.…”

“…438,439 Bromotyrosine-derived alkaloids were reported from a Greek Aplysina 1025-1028, Vietnamese Ecionemia acervus 1029 and an Egyptian Pseudoceratina arabica 1030, respectively. 421,440,441 Bromotyrosines are also commonly encountered in Suberea sponges. A Solomon Islands Suberea clavata yielded eight new bromotyrosines, subereins 1-8 1032-1039 that predicated a structural revision of two known stularin alkaloids 1031 and 1040.…”

Spongia Sponges: Unabated Sources of Novel Secondary Metabolites

“…In the cytotoxic bioassay, none of these isolates exhibited potent cytotoxic activity against HL-60 cell lines [20]. Spongiains A-G (41)(42)(43)(44)(45)(46)(47) were yielded by the Chinese marine sponge Spongia sp. Intriguingly, compounds 41-43 were the first examples of spongian diterpenes bearing a pentacyclic skeleton composed of a fused 5/5/6/6/5 ring system derived from ring A rearrangement.…”