Sea God- Sponges: Toxins and Secondary Metabolites

 Sponges produce a wide range of toxins and secondary metabolites. The deadly poisons of some of them contain the strongest toxins known in nature and complex mixtures of bioactive compounds with different chemical structures. One of the aims of this systematic review study is to study the toxinology of sea sponges as well as toxins and bioactive compounds and their functional mechanisms.

To find studies on the toxicology of sea sponges and their bioactive compounds, in April 2021, the keywords of "toxinology, toxin, secondary metabolite, alkaloid, peptide, terpene, aromatic, steroid and lactone" along with the word "sponge" or "Porifra" were searched through the Google Scholar and Pubmed databases, from 2017 to 2021. After initial reviews based on the purpose of the study, 184 out of 211 articles were selected. The search for “Porifra” and the abovementioned compounds did not yield any results. Since the limited number of studies on sponge toxins were found in the initial search, the keywords "sponge and toxin" were re-searched between 1980 and 2021 in the Pubmed database, Scifinder (database of chemical compounds) and the Marin Lit Database (marine natural compounds research), and after omitting the duplicate articles, a total of 27 other related articles were selected and reviewed along with other selected articles.

Some toxins and main compounds isolated from different sea sponges, including different chemical groups such as okadaic acid; terpene derivatives such as agelasine, oxofasciospongia, dysivillosins, and hipposponlachnins; peptides such as polytheonamides, soritesidines, and scleritodermins; many different alkaloid compounds include guanidine alkaloids such as monanchocidins, mycalins, crambescidins, unguiculins, netamines, zarzissine, hachijodines; Acridine alkaloids such as amphimedines; bromine and bromotyrosine alkaloids such as aplysinins; benzonaphthryidine derivatives such as aaptamines; imidazole derivatives such as nonamidines; indole derivatives such as fascaplysins, dragmacidins and topsentins; piperidine alkaloids such as saraines, madangamines, haliclonacyclamines, and arenosclerins; pyrimidine alkaloids such as lanesoic acid,  hyrtinadine, and variolins; pyridine alkaloids such as amphimedosides and pyrinadines; pyrrole and pyrroloiminoquinoline alkaloids such as makaluvamine, discorhabdins, tsitsikammamines and batzellines; pyrrole compounds such as hymenialdisines as well as quinoline alkaloids such as araguspongines, renieramycins, renierol and lihouidine; steroid compounds such as plakinamines; lactones such as thorectandrols, palauolol, koshikamides, petrosaspongias, latrunculins and other compounds with unique structure and biological effects.

There is a great variety of toxins and bioactive molecules in different species of sea sponges that offer a wide range of amazing pharmacological and biological activities.