Abstract

Rhododendron arboreum (Sm.) is one of the most frequently distributed an evergreen small tree species at 1500-3300 m in Nepal. The flowers of Rhododendron are a promising source of bioactive constituents and could be used as functional food and edible colorants. The purpose of this study was to reveal the components of R. arboreum flowers by LC-MS/MS. Twelve compounds were identified by LC-ESI-MS/MS from the different crude fractions prepared by liquid-liquid extraction process. The MS/MS fragmentation patterns of each compound were determined and proposed. The isolated compounds belong to flavo- noids, anthocyanins, triterpenoids and phosphatidylcholines. The major anthocyanin identified was cinnamtannin. The identified flavonoids are quercetin-3-O-glucoside, quercetin-3-O-pentoside, kaempferol-3-O-pentoside, quercetin and kaempferol. Ursolic acid represents triterpenoid derivative. 1-linoleoyl-sn-glycero-3-phosphoethanolamine, 1-linolenoyl-sn-glycero-3-phosphocho- line, 1-linoleoyl-sn-glycero-3-phosphocholine, 1-Palmitoyl-sn-glycero-3-phosphocholine and 1-oleoyl-sn-glycero-3-phospho- choline belong to phosphatidylcholines. These phosphatidylcholines have been first time reported from the genus Rhododendron.