Using Accelerated Solvent Extraction (ASE) followed by parallel chromatography to rapidly pinpoint new chemistry and scale-up the isolation of bioactive marine natural products for in vivo evaluation

We have recently transitioned away from using our venerable modified Kupchan extraction scheme in favor of a more time sensitive and highly efficient pressurized solvent extraction system commonly referred to as Accelerated Solvent Extraction or ASE. To ensure this new methodology was indeed more effective than our previous protocol, we conducted a series of separation experiments comparing the overall yields, solvent consumption and chemical stability of Kupchan extracts to those of ASE. Five marine sponges containing the following structurally distinct bioactive marine natural products: Auletta cf. constricta, milnamide C (1), jasplakinolide (2); Cacospongia mycofijiensis, latrunculin A (3), fijianolide B (4), mycothiazole (5); Fascaplysinopsis reticulata, fascaplysin (6); Jaspis coriacea, bengamide E (7) and Zyzzia fuliginosa, makaluvamine C (8), were selected for processing. The extracts from either method were evaluated for their total overall yields and assessed for any chemical degradation using comparative LC/MS with standard chromatograms. Total extract yields involving ASE were comparable or greater to those of the Kupchan method, however, required substantially less solvent and time to process while maintaining the structural integrity of the host chemistry. Extract yields using ASE allowed for clonogenic analysis to be performed on compounds 1-4 and 8. In addition, 15 distinct samples of C. mycofijiensis were extracted using ASE and profiled using Parallel HPLC Chromatography (PHC), which lead to the discovery of a series of novel sesquiterpenes. These results demonstrate that ASE followed by PHC, are effective high throughput methodologies for rapidly generating stable marine extracts for scale-up isolation as well for disclosing novel marine natural products.

milnamide C (1)

jasplakinolide (2)

latrunculin A (3)

mycothiazole (4)

fijianolide B (5)

fascaplysin (6)

bengamide E (7)

makaluvamine C (8)