Comprehensive Characterisation of n‐Alkylresorcinols and Other Lipid Constituents of Mercurialis tomentosa L. from Alicante,Spain |
| |
Authors: | Peter Lorenz Miriam Heinrich Jürgen Conrad Annerose Heller Florian C Stintzing Dietmar R Kammerer |
| |
Institution: | 1. Section 2. Phytochemical Research, Department of Analytical Development & Research, WALA Heilmittel GmbH, Bad Boll/Eckw?lden;3. Institute of Chemistry, Bioorganic Chemistry (130b), University of Hohenheim, Stuttgart;4. Institute of Botany (210), University of Hohenheim, Stuttgart |
| |
Abstract: | Mercurialis tomentosa L. has been used in Spanish ethnomedicine. In the present study the first phytochemical characterisation of a lipid fraction from M. tomentosa was performed. The CHCl3 extraction of aerial parts from M. tomentosa and GC/MS investigations revealed the occurrence of cuticular lipid and wax constituents, like long chain n‐alcohols and n‐aldehydes (C22 – C30), besides several aromatic constituents, i.e., phenylpropanoids and n‐alkylresorcinols. The latter were further purified by CC and analysed by LC/MSn. In contrast to other Mercurialis species, i.e., M. annua, M. perennis, which exclusively contain 5‐n‐alkylresorcinols ( 1a – j , Cn), mainly 5‐n‐alkyl‐2‐methylresorcinols ( 2a – j , Cn*) with side chain lengths of C15 – C25 were found in M. tomentosa, in addition to 1a – j . Thus, the latter compounds may be utilised for analytical characterisation and authentication of M. tomentosa based on fingerprinting methods. For structure elucidation a novel facile total synthesis of one representative 5‐n‐alkyl‐2‐methylresorcinol homologue ( 2d , C19*) was developed, starting with a Grignard reaction from a substituted benzoic acid chloride ( 19 ). The compound obtained by synthesis was identical to the natural product 2d in terms of its chromatographic and spectroscopic features. Futhermore, 2d exhibited satisfactory DPPH free radical scavenging activity (IC50 = 37.8 μm ) when compared to trolox (IC50 = 21.0 μm ), corroborating the antioxidant features of these amphipathic molecules. |
| |
Keywords: | Euphorbiaceae Lipids Chemotaxonomy n‐Alkylresorcinols Antioxidants |
|
|