Osmanthus, a genus of about 30 species of flowering plants in the family Oleaceae, is native to eastern Asia1. Among these, Osmanthus fragrans, also known as sweet osmanthus, sweet olive, tea olive, and fragrant olive, is particularly renowned for its unique floral color and fragrance2.
The fragrance of Osmanthus fragrans is formed by a variety of endogenous metabolites that distinguish it from other flowers3. The golden-orange flowers are most used in perfumery as they’re said to produce the best scent from extraction. The higher concentration of carotenoids in their chemical make-up contributes to their more vivid orange color as well as to making their fragrance richer4.
The Chemistry Behind the Fragrance
The chemical constituents of Osmanthus fragrans have been studied extensively. More than 20 phytochemicals have been identified in osmanthus fragrans, such as acteoside, salidroside, and ligustroside, which have antioxidant effects5. A study on the branches of Osmanthus fragrans “Ziyingui” isolated eight compounds, including clemaphenol A, sylvatesmin, phillyrin, (+)-cycloolivil, 4-hydroxyphenylethanol, syringin, koaburaside, and 5-hydroxymethyl-2-furancarboxaldehyde6. These compounds were identified and confirmed by comparing the literature data with their 1H NMR, 13 C NMR, and HMBC6.
Biological Activities of Osmanthus Compounds
The isolated compounds from Osmanthus fragrans exhibit various biological activities. For instance, they showed inhibitory activities on α-glucosidase and α-amylase6. The antioxidant activity of these compounds was measured by DPPH and ABTS radical scavenging assays6. Compounds 4 and 7 displayed strong DPPH radical scavenging activities, while compounds 1, 4, and 5 exhibited potent ABTS radical scavenging activities6.
Osmanthus fragrans, the most fragrant plant in Asia, owes its unique scent to a complex mixture of chemical compounds. The understanding of these compounds not only unravels the mystery behind the fragrance of Osmanthus but also opens up potential applications in various fields such as perfumery, food industry, and therapeutics. The exploration of the chemistry of Osmanthus fragrans is a fascinating journey into the world of fragrances, demonstrating the intricate interplay between chemistry and nature.
