title: Chemical profiling (HPLC-NMR & HPLC-MS), isolation, and identification of bioactive meroditerpenoids from the southern Australian marine brown alga Sargassum paradoxum.
abstract: A phytochemical investigation of a southern Australian marine brown alga, Sargassum paradoxum, resulted in the isolation and identification of four new (5, 9, 10, and 15) and nine previously reported (1, 2, 6-8, and 11-14) bioactive meroditerpenoids. HPLC-NMR and HPLC-MS were central to the identification of a new unstable compound, sargahydroquinal (9), and pivotal in the deconvolution of eight (1, 2, 5-7, and 10-12) other meroditerpenoids. In particular, the complete characterization and identification of the two main constituents (1 and 2) in the crude dichloromethane extract was achieved using stop-flow HPLC-NMR and HPLC-MS. This study resulted in the first acquisition of gHMBCAD NMR spectra in the stop-flow HPLC-NMR mode for a system solely equipped with a 60 μL HPLC-NMR flow cell without the use of a cold probe, microcoil, or any pre-concentration.
authors.affiliation: School of Applied Sciences (Discipline of Chemistry), Health Innovations Research Institute (HIRi) RMIT University, GPO Box 2476V Melbourne, Victoria 3001, Australia. robert.brkljaca@rmit.edu.au.
authors.forename: Robert
authors.initials: R
authors.lastname: Brkljača
authors.affiliation: School of Applied Sciences (Discipline of Chemistry), Health Innovations Research Institute (HIRi) RMIT University, GPO Box 2476V Melbourne, Victoria 3001, Australia. sylvia.urban@rmit.edu.au.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Urban
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D016227:Benzoquinones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006873:Hydroquinones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D044647:Sargassum / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D016227:Benzoquinones; D004224:Diterpenes; D006873:Hydroquinones