Antifouling activity of the sponge metabolite agelasine D and synthesised analogs onBalanus improvisus

Abstract

This study reports a screening study for antifouling (AF) activity of the natural compound agelasine D isolated from marine sponges of the genus Agelas and 20 synthesised analogs of agelasines and agelasimines. Agelasine D, together with two of the analogs, ie AV1003A and AKB695, displayed a strong inhibitory effect on settlement of Balanus improvisus cypris larvae. Agelasine D had an EC50 value of 0.11 microM while the two analogs AV1033A and AKB695 had EC50 values of 0.23 and 0.3 microM, respectively. None of these three compounds affected larval mortality as was the case with several of the analogs tested. Moreover, the effect of AV1033A and AKB695 was reversible. When cyprids after 24 h exposure to the compounds were transferred to fresh seawater, the settlement frequency compared with the controls was completely recovered. The properties of the agelasine D analogs AV1003A and AKB695 make them highly attractive candidates as AF agents in future marine coatings.

Natural compounds with P2X7 receptor-modulating properties

“…These compounds have gained attention because of their biological activity to confer cytotoxicity towards cancer cell lines (minimal inhibitory concentrations of ca. 1 μM; for review see [45]), as well as their anti-bacterial, anti-fungal and anti-protozoal properties [46][47][48][49]. New analogues have been synthesized with activities against Mycobacterium tuberculosis , protozoa such as Plasmodium falciparum and Leishmania infantum as well as against drug-resistant cancer cell lines [50].…”

Terpenyl-Purines from the Sea

“…When after 24 h exposure to the compounds the cyprids were transferred to fresh seawater, the settlement frequency was completely recovered in comparison with the controls. These properties make agelasine D and analogs highly attractive candidates as antifouling agents in future marine coatings [43]. The antifouling activity of epi -agelasine C against Ulva spores is not as high as that of CuSO 4 (positive control); however, epi -agelasine C shows lethal activity against Ulva fronds at 50 ppm.…”

“…Such compounds have attracted the attention of researchers because of their potent biological activities, which have been reported to include antimicrobial [34,35], antiproliferative [36], antileukemic [37], cytotoxic [34,38], antiprotozoal [39,40] and antituberculosis properties [41] and inhibitory effects on the enzymatic reactions of Na + ,K + -ATPase [42]. Another reason that led to the evaluation of genera of sponges is that a significant number of sponge metabolites show promising activities in antifouling assays [43]. …”

The First Synthesis of (–)‐Agelasine F; an Antimycobacterial Natural Product Found in Marine Sponges in the Agelas Genus

“…Some steps in the synthesis of the desired enantiomer of the key‐intermediate 5 are shown in Scheme . As a continuance of our work directed to synthesis of agelasines and analogs, and evaluation of their biological activities, we herein present the first total synthesis of the naturally occurring (–)‐agelasine F.…”