Identification and Characterization of Two New Derivatives of Chlorogenic Acids in Arnica (Arnica montana L) Flowers by High-Performance Liquid Chromatography/Tandem Mass Spectrometry

摘要

Arnica montana is a medicinally important plant due to its broad health effects, and-it is used in Ayurvedic, Homeopathic, Unani, and folk medicines. We have used LC-MS" (n = 2-5) to detect and characterize in Arnica flowers 11 quantitatively minor fumaric and mefhoxyoxalic acid-containing chlorogenic acids, nine of them not previously reported in nature. These comprise l,S-dicaffeoyl-3-mefhoxyoxaloylquinic acid, 1,3-dicaffeoyl-4-methoxyoxaloylquinic acid, 3,S-dicaffeoyl-4-methox-yoxaloylquinic acid, and l-methoxyoxaloyl-4,S-dicaffeoylquinic acid (M_r 602); 3-cafleoyl-4-feruloyl-5-methoxyoxaloylquinic acid and 3-feruloyl-4-methoxyoxaloyl-S-carfeoylquinic acid (M_r 616); 1,5-dicaffeoyl-4-fumaroyl and 1,5-dicaffeoyl-3,-fumaroylquinic acid (M_r 614); 3,5-dicaffeoyl-1,4-dimethoxyoxaloylquinic acid (M_r 688); and l-methoxyoxaloyl-3,4,5-tricaffeoylquinic acid and 1,3,4-tricaffeoyl-5-methoxyoxaloylquinic acid (M_r 764). All of the structures have been assigned on the basis of LC-MS" patterns of fragmentation, relative hydrophoblcity, and analogy of fragmentation patterns if compared to caffeoylquinic acids. This is the first time when fumaric acid-containing chlorogenic acids are reported in nature.