Abstract
A rapid method for the simultaneous detection and identification of radical scavenging compounds in plant extracts was developed by combining an HPLC with on-line radical scavenging using DPPH as a model radical and an HPLC¿DAD¿SPE¿NMR system. Using this method a commercial rosemary extract was investigated. All major compounds present in the extract were collected on SPE cartridges after their separation. Advantages of on-line SPE peak trapping are the possibility to perform HPLC with non-deuterated solvents, a concentration effect and being able to record NMR spectra in pure 100% deuterated solvents. After comparing DAD and DPPH scavenging chromatograms, 1H NMR spectra of compounds having radical scavenging activities were recorded. Afterwards all compounds were collected and infused into an ESI-MS. The five main active compounds ¿ carnosol, carnosic acid carnosaldehyde, 12-methoxycarnosic acid and epiisorosmanol ¿ could be identified from the combined UV, NMR and mass spectral data without actually isolating them. It was possible to record on-line an HMBC spectrum of carnosic acid. Also one compound was tentatively identified as epirosmanol methyl ether
Original language | English |
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Pages (from-to) | 81-88 |
Journal | Journal of Chromatography. A, Including electrophoresis and other separation methods |
Volume | 1074 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - 2005 |
Keywords
- rosmarinus-officinalis l
- carnosic acid
- phenolic diterpenes
- salvia-officinalis
- rosemary extracts
- online detection
- sage extracts
- flow-probe
- constituents
- oil