Trimeric Hemibastadin Congener from the Marine Sponge <i>Ianthella basta</i>

Abstract

The first naturally occurring trimeric hemibastadin congener, sesquibastadin 1 (<b>1</b>), and the previously reported bastadins 3, 6, 7, 11, and 16 (<b>2</b>–<b>6</b>) were isolated from the marine sponge <i>Ianthella basta</i>, collected in Indonesia. The structure of <b>1</b> was elucidated on the basis of 1D and 2D NMR measurements and by HRMS. Among all the isolated compounds, the linear sesquibastadin 1 (<b>1</b>) and bastadin 3 (<b>2</b>) showed the strongest inhibition rates for at least 22 protein kinases (IC₅₀ = 0.1–6.5 μM), while the macrocyclic bastadins (<b>3</b>–<b>6</b>) demonstrated a strong cytotoxic potential against the murine lymphoma cell line L5178Y (IC₅₀ = 1.5–5.3 μM)