An anti-mycobacterial bisfunctionalized sphingolipid and new bromopyrrole alkaloid from the Indonesian marine sponge Agelas sp

Abstract

In the course of our studies on anti-mycobacterial substances from marine organisms, the known dimeric sphingolipid, leucettamol A (1), was isolated as an active component, together with the new bromopyrrole alkaloid, 5-bromophakelline (2), and twelve known congeners from the Indonesian marine sponge Agelas sp. The structure of 2 was elucidated based on its spectroscopic data. Compound 1 and its bis TFA salt showed inhibition zones of 12 and 7 mm against Mycobacterium smegmatis at 50 μg/disk, respectively, while the N,N'-diacetyl derivative (1a) was not active at 50 μg/disk. Therefore, free amino groups are important for anti-mycobacterial activity. This is the first study to show the anti-mycobacterial activity of a bisfunctionalized sphingolipid. Compound 13 exhibited weak PTP1B inhibitory activity (29% inhibition at 35 μM).

Keywords: Bromopyrrole alkaloid; Leucettamol A; Marine sponge Agelas sp.; Mycobacterium smegmatis; Protein tyrosine phosphatase 1B.