Analysis of Volatile Constituents in Tectona grandis L.F. Before and After Irradiation by HS-SPME-GC-MS
2017, 37 (1):
Headspace solid-phase micro-extraction(HS-SPME) combined with gas chromatography-mass spectrometry(GC-MS) technology was used to analyze the volatile constituents in original and irradiated Tectona grandis L.F.. The results showed that 80 kinds of volatile constituents were identified. There were 57 volatile constituents in T. grandis without irradiation and 53 volatile constituents in T. grandis after irradiation. They included hydrocarbons, alcohols, phenols, esters, aldehydes, ketone, anthraquinone and amine. After irradiation, the ketone in the volatile constituents disappeared, the content of alcohols decreased to 7.498% from 12.586% and the species decreased to 3 from 6, and the aldehydes increased to 3.653% from 0.404% with the species of 5 from 3. The major volatile constituents before irradiation were 2-methyl-anthracenedione(18.443%), 2-N-methyl-naphthalenamine(14.781%), phthalic acid-isobutyl octyl ester(9.567%), 1,2,3-trimethyl-4-propenyl-(E)-naphthalene(7.513%), τ-cadinol(4.684%), α-cadinol(3.583%), cedrol(3.576%) and 1,2-benzenedicarboxylic acid-butyl 2-methylpropyl ester(3.213%), respectively. After irradiation, the α-cadinol and 1,2-benzenedicarboxylic acid-butyl 2-methylpropyl ester disappeared, the 1,2-benzenedicarboxylic acid-butyl cyclohexyl ester appeared with the content of 3.070%, the content of phthalic acid-isobutyl octyl ester increased by 2.22 percentage points, and the contents of others changed little. The alcohol volatile components might be oxidized to the aldehydes volatile components by irradiation. The aldehydes contains the chromophoric group of -CHO, and the alcohols contains the auxochrome group of -OH, and the significant increase of the constituents after irradiation contains the chromophoric group of -COO-. The hydroxyl, aldehyde group and ester group might play an important role in the T.grandis photo-discoloration, but to well understand the the mechanism of photo-discoloration, further studies were needed.
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