Abstract:In order to explore the chemical constituents of essential oils in Jasminum sambac ‘Unifoliatum’ during different flower development stages, the changes in chemical composition and contents of ‘Unifoliatum’ were analyzed by using head solid-phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) methods. The results showed that the constituents and contents of essential oils in ‘Unifoliatum’ flowers were significantly different among different flower development stages. There were 7, 25, 27, 23 and 16 compounds, identified at early bud, mature bud, slight open, bloom and late bloom stages, respectively. Terpens were the major constituents at early bud stage. The contents of alcohols, esters and terpenes were high, which were the main constituents at mature bud stage, as well as at slight open and bloom stages, nevertheless the specific compounds and their contents were distinctly different at these stages. Terpens and heterocycle were the major constituents at late bloom stage. The main constituents or precursors of essential oils had basically formed at mature bud stage, and most of them reached maximum content at slight open stage. Therefore, the fresh flowers at slight open stage should be plucked for extracting jasmine essential oils or scenting tea. However, if extracting jasmine essential oils or scenting tea could not be timely, the best harvest time might be throughout the mature bud stage.
