ChemInform Abstract: Netamines O—S, Five New Tricyclic Guanidine Alkaloids from the Madagascar Sponge Biemna laboutei, and Their Antimalarial Activities.

Abstract

In our continuing program to isolate newcompounds from the Madagascar sponge Biemna laboutei, five new tricyclic guanidine alkaloids,netamines O-S(1 -5,resp.), havebeen identifiedtogether with the known compounds netamine E( 6)a nd mirabilin J( 7). Thes tructures of all new netamines were assigned on the basis of spectroscopic analyses.Their relative configurationswere established by analysis of ROESY data and comparison with literatured ata. Netamines O, P, and Q, which werei solated in sufficient quantities, were tested for their cytotoxic activities against KB cells and their activities against the malaria parasite Plasmodium falciparum.Netamines Oand Qwere foundtobemoderately cytotoxic. Netamines O, P, and Qe xhibited antiplasmodialactivities with IC 50 values of 16.99 AE 4.12, 32.62 AE 3.44, and 8.37 AE 1.35 mm,respectively.Introduction. -T ricyclic guanidinec ompounds,b earingatricyclic 2-amino-1,3-diazaoctahydroacenaphtylene skeleton, like ptilocaulins,mirabilins, and netamines,are restricted to marine sponges of the order Poecilosclerida [1 -11] and can be grouped on the basis of their degree of oxidation and C¼Cb ond position with pyrimidine, D

Metabolites from Marine Sponges and Their Potential to Treat Malarial Protozoan Parasites Infection: A Systematic Review

“…Alkaloids from marine sponges have shown potential against infectious diseases, particularly against malaria. The natural alkaloids identified are grouped as pyrrole-imidazole [23,27], indole-imidazole [33], indole [21], manzamine [45,57], ingamine alkaloids [39], bromotyrosine [43], guanidine [28,30,32] phloeodictynes [51], pentacyclic quinones [50], pyrroloiminoquinone [38], thiazine alkaloids [34], and diterpene alkaloids [48,58] .…”

“…Guanidine alkaloids are representative antimalarial NPs [28,30,32,60], including netamines G-S from Madagascar sponge Biemna laboutei (Biemnidae family, Poecilosclerida) (27)(28)(29)(30)(31)(32)(33)(34) [28,30,32] and phloeodictynes mixtures (35)(36)(37)(38)(39)(40)(41)(42) from Oceanapia fistulosa [51] (Table 1). Compounds containing guanidine moiety with pentacyclic skeleton (29)(30)(31)(32)(33)(34) were demonstrated to be more potent, particularly ptilomycalin F (30) and fromiamycalin (34) (IC 50 of 0.23 and 0.24 µM, respectively) [28].…”

Recent Advances on Marine Alkaloids from Sponges

“…[40] Compounds 50-54 were obtained from a Madagascar sponge Biemna laboutei and characterized as tricyclic (5/6/6) guanidine alkaloids, which were similar to compound 41. [41] Seven new compounds 55-61, four bicyclic and three pentacyclic guanidine alkaloids, were isolated form a French Polynesian Monanchora n. sp. sponge.…”