ABSTRACT
Objective: To study the chemical constituents from the stem barks of Engelhardtia roxburghiana. Methods: The compounds were isolated and purified by various chromatographic techniques and their structures were elucidated by spectral analysis. Results: Ten compounds were obtained and identified as eudesm-4(15)-ene-1β, 6α-diol (1), (4S)-4-hydroxy-1-tetralone (2), (-)- regiolone (3), p-hydroxybenzoic acid (4), kaempferol (5), isolicoflavonol (6), broussoflavonol F (7), broussonol E (8), kaempferol-3-O- α-L-rhamnoside (9), and quercetin-3-O-α-L-rhamnoside (10). Conclusion: Compounds 1, 4, and 6-8 are isolated from the plants of Engelhardtia Leschen. et Bl. for the first time, and the prenylated flavonoids are firstly reported in this genus.
ABSTRACT
OBJECTIVE: To investigate the chemical constituents of the leaves of Engelhardtia roxburghiana. METHODS: After the plant materials were extracted and fractionated with solvents, column chromatography was used to isolate and purify the compounds. The structures were elucidated on the basis of 1H-NMR, 13C-NMR, MS analysis and comparison with the literature data. RESULTS: Thirteen compounds were identified as following; taxilfolin (1), 5,7,4'-trihydroxy flavanone(2), kaempferol (3), dihydrokaempferol (4), quercetin(5), isoengeletin(6), engeletin (7), astilbin(8), isoastilbin(9), kaempferol-3-O-α-L-rhamnoside(10), eucryphin (11), 5-hydroxy-3,7,3',4'-tetramethoxyflavone(12), quercetin-3-O-α-L-rhamnoside (13). CONCLUSION: Compounds 2, 4, 9, 11 and 12 were identified from the title plant for the first time.