Study On The Chemical Constituents And Their Bioactivities From Aquilaria Sinensis And Agarwood Induced By Artificial Holing

Aquilaria sinensis (Lour.) Gilg belongs to the genus Aquilaria of the family Thymelaeaceae. It is reported that A.sinensis contains chemical constituents such as flavonoids, terpenoids, lignans, steroids, etc. has shown several pharmacological activities such as anti-tumor, anti-bacterial, anti-inflammatory analgesic, laxative effect and a-glucosidase inhibitory, etc. Agarwood can be formed gradually when healthy A. sinensis is hurt by natural or artificial effect. The main constituents of agarwood were sesquiterpenes and2-(2-phenylethyl) chromone derivatives as reported. As a traditional Chinese medicine, agarwood can be used for chest pain, bloating, nausea, vomiting, hiccups, etc.Compounds1-16were isolated from the n-butanol extract of A. sinensis using column chromatography. On the basis of spectroscopic (UV, IR, MS, ID and2D NMR) analysis and physiochemical properties, the structures of compounds1-16were identified respectively as threo-buddlenol C (1), thero-ficusesquilignan A (2), erythro-buddlenol C (3),(±)-buddlenol D (4),(-) medioresinol (5),(-) pinoresinol (6),5’-methoxy lariciresinol (7), erythro-guaiacylglycerol-β-coniferyl ether (8),threo-guaiacylglycerol-β-coniferyl ether (9), herpetin (10),(+) syringaresinol (11), curuilignan (12), ciwujiatone (13), coniferyl alcohol (14),3,4,5-trimethoxyphenol (15), cucurbitacin (16). Compounds1-13were lignans, and compounds1-4were sesquilignans, which have been isolated from family Thymelaeaceae for the first time.Compounds17-54were obtained from the agarwood induced by artificial holing using column chromatography. Their structures were identified based on spectroscopic (UV, IR, MS, ID and2D NMR) analysis and physiochemical properties as follows:8a,12-dihydroxy-selina-4,11-dien-14-al (17),9β-hydroxy-selina-4,11-dien-14-al (18),9β-hydroxy-selina-3,11-dien-14-al (19),9β-hydroxy-selina-3,11-dien-12-al (20),9β-hydroxy-eudesma-3,11(13)-dien-12-methyl ester (21),1,5;8,12-diepoxy-guaia-12-one (22),4-epi-15-hydroxyacorenone (23),7aH-9(10)-ene-11,12-epoxy-8-oxoeremophilane (24),12,15-dioxo-a-selinen (25),(4αβ,7β,8αβ)-3,4,4a,5,6,7,8,8a-octahydro-7-[1-(hydroxylmenthyl)ethenyl]-4a-methylnaphthalene-1-carboxaldehyde (26), eudesmane-1β,5a,11-triol (27),(-)-7βH-eudesmane-4a,11-diol (28), ent-4(15)-eudesmen-11-ol-l-one (29), valerianol (30),11-hydroxy-valenc-1(10)-en-2-one (31), neopetasane (32),(1β,4αβ,7β,8αβ)-octahydro-7-[1-(hydroxymenthyl)ethenyl]-1,8a-dimethylnaphthalen-4a (2H)-ol (33),1,5,9-trimethyl-1,5,9-cyclododecatriene (34),5-hydroxy-6-methoxy-2-[2-(3-hydroxyl-4-methoxyphenyl)ethyl] chromone (35),6-methoxy-2-[2-(3-hydroxy-4-methoxy phenyl)ethyl]chromone (36),5,6-epoxy-7β-hydroxy-8β-methoxy-2-(2-phenylethyl) chromone (37),6-methoxy-2-[2-(3-methoxy-4-hydroxyphenyl)ethyl]chromone (38),5-hydroxy-6-methoxy-2-[2-(4-methoxyphenyl)ethyl]-4H-1-benzopyran-4-one (39),6-methoxy-2-[2-(4-methoxyphenyl)ethyl]chromone (40),6-methoxy-2-[2-(3-methoxy phenyl)ethyl]chromone (41),6,7-dimethoxy-2-(2-phenylethyl)chromone (42),6,8-dihydroxy-2-(2-phenylethyl)chromone (43),4’-hydroxy-6-methoxy-2-(2-phenylethyl) chromone (44), oxidoagarochromone A (45), oxidoagarochromone B (46),5-hydroxyl-7,4’-dimethoxyflavone (47),3-hydroxy-4-methoxy-methyl ester (48), zingerone (49), p-methoxy phenylpropionic acid (50), n-dotriacontanol (51),(20R)-24-ethylcholest-4-en-3-one (52), ergosta-4,6,8(14),22-tetraene-3-one (53), stigmasterol (54). Compounds17-34were sesquiterpenes and compounds35-46were2-(2-phenylethyl) chromone derivatives, among which there were ten new compounds.The antibacterial activites against Staphylococcus aureus and Ralstonia solanacearum of compounds1-54were measured by the method of using paper disco diffusion. The results showed that compounds1,4,20-21,23-26,32,45-46,49had a certain inhibitory activity towards both of the two kinds of bacteria, while compounds8,13,17,36,39showed some inhibitory activity against S. aureus only as well as compound3,32,53to R. solanacearum. The acetylcholinesterase inhibitory activities were tested in vitro using the spectrophotometric method developed by Ellman with slightly modification. The results showed that compounds20,22-26,28,32,35-37,40,42,44-46exhibited weak AChE inhibitory activities.Thirteen lignans have been obtained from this study, and combined with previous studies on A. sinensis, it can be known that the main chemical constituents from the stems of A. sinensis were lignans and flavonoids. The study of agarwood induced by artificial holing found sesquiterpenes and2-(2-phenylethyl) chromone derivatives were the main constituents, which was consistent with literatures reported on agarwood. Therefore, the chemical constituents of A. sinensis and agarwood exists obvious differences. The differences not only can be used to distinguish agarwood from A. sinensis but also can evaluate the quality of agarwood better and reveal the mechanism of agarwood production. And it can also provide scientific basis for better development and utilization of A. sinensis and agarwood resources.