Discorhabdins from the Korean Marine Sponge Sceptrella sp.

Abstract

Two new pyrroloiminoquinone alkaloids of the discorhabdin class, along with 12 compounds including one previously described synthetic derivative of the same and related skeletal classes, were isolated from the sponge Sceptrella sp., collected from Gageodo, Korea. The structures of these new compounds, designated as (-)-3-dihydrodiscorhabdin D (11) and (-)-discorhabdin Z (12), were determined by combined spectroscopic analyses. Compound 12 possesses an unusual hemiaminal group among the discorhabdin alkaloids. These compounds exhibited moderate to significant cytotoxicity, antibacterial activity, and inhibitory activity against sortase A.

Sortase A: An ideal target for anti-virulence drug development

“…An additional class of marine compounds displaying antibacterial and SrtA inhibitory activity are the pyrroloiminoquinone alkaloids found in the sponge Sceptrella sp.. In particular, (À)-discorhabdin Z, one of the two new alkaloids characterized by an unusual hemiaminal group, inhibited S. aureus SrtA with an IC 50 of 2.19 mg/ml and without deffects on microbial viability (MIC > 100 mg/ml) [62]. Moreover, a new SrtA inhibitor with an IC 50 of 21.34 mg/ml was found among the sesterterpenes and related pentaprenyl hydroquinones (halisulfates and suvanine) isolated from the sponge Coscinoderma sp.…”

An Antibacterial 9,11-Secosterol from a Marine Sponge Ircinia sp.

“…2 A number of antibacterial compounds have also been reported from the marine spongederived metabolites including discorhabdin Z, 3 agelasine D, 4 7,20-diisocyanoadociane, 5 motualevic acid F. 6 In this regard, we have been investigating the anti-bacterial compounds from extracts of Korean marine sponges. An extract of a marine sponge in the genus of Ircinia showed antibacterial activities and its bioactive constituents have been investigated.…”

Antimicrobial lead compounds from marine plants

“…Two pyrroloiminoquinone alkaloids of class discorhabdin from sponge Sceptrella sp. from Gageodo, Korea [33] showed antibacterial potency, especially against enzyme sortase A, with a key role in anchoring of cell wall protein responsible for S. aureus virulence. 19-oxofasciospongine A and fasciospongine C (sulfated sesterterpene alkaloids) and 25-hydroxyhalisulfate 9 (sesterterpene sulfate), found recently and known sesterterpenes sulfates halisulphates 7 and 9, have been extracted from marine sponge Fasciospongia sp.…”