Potential of UHPLC for crude plant extract analysis: profiling, dereplication and metabolomics

Ultra High Pressure Liquid Chromatography (UHPLC) systems operating at very high pressures and using sub-2µm packing columns have allowed a remarkable decrease in analysis time and increase in peak capacity to HPLC [1]. UHPLC has rapidly been accepted and is gradually applied to various fields of plant analysis such as quality control, profiling and fingerprinting, dereplication and metabolomics. The shorter analysis time and the sharper peaks produced by UHPLC require detectors with sufficiently high acquisition rates. In this respect, UV/DAD, evaporative light scattering detector (ELSD) and time-of-flight mass analyzers (TOF-MS) are particularly well adapted [2]. Examples of fast fingerprinting (high throughput) and precise profiling of crude plant extracts (high resolution) will be presented, and compared with classical HPLC methods. Gradient transfer methods and applications of high temperature will be discussed as well. UHPLC coupled to MS represents a powerful platform for the rapid on-line identification of natural products. Through the high mass accuracy of the TOF-MS measurements, molecular formula provides a universal way to characterize natural products (NPs). However, for an efficient cross search in databases, an instrument-independent retention parameter is needed. In this respect, attempts to standardize the chromatographic dimension of the LC-MS datasets have been made. A protocol to extract online the log P parameter in specific profiling conditions [3] from the retention behavior of NPs, as standards or in extracts, will be presented.

References: 1. Guillarme, D. et al. (2007)J. Chromatogr. A. 2007, 1149, 20–29.

2. Wolfender, JL. et al. (2009) Planta Med. 75, 719–734.

3. Henchoz, Y. et al. (2008)J. Med. Chem., 51, 396–99.