Orthoscuticellines A–E, β-Carboline Alkaloids from the Bryozoan Orthoscuticella ventricosa Collected in Australia

Abstract

Antiplasmodial high-throughput screening of extracts derived from marine invertebrates collected from northern NSW, Australia, resulted in the methanol extract of the bryozoan Orthoscuticella ventricosa being identified as inhibitory toward the 3D7 strain of Plasmodium falciparum. Purification of this extract resulted in two new bis-β-carbolines that possess a cyclobutane moiety, orthoscuticellines A and B (1 and 2), three new β-carboline alkaloids, orthoscuticellines C−E (3−5), and six known compounds, 1-ethyl-4methylsulfone-β-carboline ( 6), 1-ethyl-β-carboline ( 7), 1-acetyl-β-carboline (8) 1-(1′-hydroxyethyl)-β-carboline ( 9), 1-methoxycarbonyl-β-carboline (10), and 1-vinyl-β-carboline (11). The structures of all compounds were determined from analysis of MS and 1D and 2D NMR data. The compounds showed modest antiplasmodial activity against P. falciparum in the range of 12−21 μM.

Natural products dereplication by diffusion ordered NMR spectroscopy (DOSY)

“…Resonances associated with acidic protons such as those present in carboxylic acids or phenols can undergo chemical exchange with residual H 2 O, resulting in signal broadening up to a point where these resonances cannot be seen in a 1 H NMR spectrum. Second, several compounds in our dataset (doxycycline hyclate (45) 53 and rutin (48)) displayed resonances for intramolecular H-bonded phenols below the eff d H limit of 14.00 ppm (d H 11.48, 12.44 and 12.60 ppm respectively). These intramolecular Hbonded phenolic resonances are identiable as they are sharper than other phenols in their spectra that can undergo chemical exchange with H 2 O.…”

“…We have recently published the structures of several new brominated alkaloids isolated from the bryozoan Amathia lamourouxi. 48 To further test the application of this dereplication methodology, we acquired DOSY data for both the free bases and TFA salts of (70 and 71) and K (72 and 73) and the free base of volutamine F (74). Their D pre vs. D exp were all within 5.5% error.…”

Potentials of marine natural products against malaria, leishmaniasis, and trypanosomiasis parasites: a review of recent articles

“…The two bis-β-carbolines (orthoscuticellines A and B) has a cyclobutane moiety. The compounds showed moderate activity against the same parasite (12-21 μmol/L) while some had cytotoxicity effects on human embryonic kidney cells (40 µmol/L) [27].…”

Tedaniophorbasins A and B—Novel Fluorescent Pteridine Alkaloids Incorporating a Thiomorpholine from the Sponge Tedaniophorbas ceratosis

“…Due to the paucity of chemical data reported for species from this region, we have initiated a project to investigate the chemical diversity in relation to the sessile marine invertebrate biodiversity of the region. To date, we have collected over 500 sponges, ascidian, and bryozoan specimens from reefs from this region, and a systematic analysis of the chemistry they contain has been initiated [7][8][9][10][11][12]. Herein, we report on the isolation, structure determination, and biological activity of two new alkaloids, tedaniophorbasins A (1) and B (2), possessing a novel skeleton (Figure 1) that we have isolated from Tedaniophorbas ceratosis collected from oceanic waters adjacent to Cook Island in far northern New South Wales, Australia.…”

“…of the region. To date, we have collected over 500 mens from reefs from this region, and a systemat has been initiated [7][8][9][10][11][12]. Herein, we report on th biological activity of two new alkaloids, tedaniop novel skeleton ( Figure 1) that we have isolated fro oceanic waters adjacent to Cook Island in far nor is the first report on the chemistry of sponges fro…”