Arnica chemistry has a number of flavonoid glycosides identified in arnica, many these chemical compounds are extensive and in many cases unclear hour they interact with the healing process. Flavonoids (0.4% to 0.6%) include the following: betuletol, eupafolin, flavonol glucuronides, hispidulin, isorhamnetin, luteolin, patuletin, spinacetin, tricin, -trihydroxy -trimethoxyflavone, kaempferol, quercetin, kaempferol and quercetin derivative, jaceosidin, and pectolin-arigenin. Isomeric alcohols include arnidiol and foradiol. Terpenoids in arnica include the following: arnifolin, arnicolide, and the sesquiterpenes helenalin (and derivatives) and dihydrohelenalin. The pseudoguaianolide ester helenalin methacrylate has been isolated from the flowers. The quantity of sesquiterpene lactones varies widely among species and geographical location, making standardization of preparations difficult. The European Pharmacopoeia recommends a minimum sesquiterpene lactone content of 0.4% in Arnica montana preparations used as herbal medicines. Amines present in the plant are betaine, choline, and trimethylamine. Coumarins include scopoletin and umbelliferone. Carbohydrates, such as mucilage and polysaccharides (eg, inulin), are found in arnica. Two homogeneous polysaccharides include an acidic arabino-galactan-protein and a neutral fucogalactoxyloglucan. Further polysaccharide isolation has been performed on a group of water-soluble acidic heteroglycans.
Volatile oils (0.3% to 1%) may be obtained from rhizomes and roots or from flower parts and are used in perfume. Constituents in the oil include thymol, its derivatives, and fatty acids (eg, palmitic, linoleic, myristic, linolenic). The fatty acid content in arnica leaf essential oil has been evaluated as well. Other components found in arnica include bitter compound arnicin, caffeic acid, carotenoids (alpha- and beta-carotene, cryptoxanthin, lutein), phytosterols, resin, tannins, lignans, and anthoxanthine.