ABSTRACT
Three new 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromones and one new dimeric 2-(2-phenylethyl)chromone were isolated from the agarwood of Aquilaria crassna Pierre ex Lecomte in Laos. The structures of the isolates were elucidated by spectroscopic methods, and their configurations were determined via ROESY correlations, 3 J H-H coupling constants analyses, comparisons of chemical shifts and specific rotations with known compounds, and ECD calculation in the case of 1. Compounds 1-4 were evaluated for their cytotoxicity. Compounds 1 and 2 exhibited weak cytotoxicity toward HeLa cell line (IC50: 49.8 ± 1.2 µM) and K562 cell line (IC50: 42.66 ± 0.47 µM), respectively.
Subject(s)
Flavonoids/isolation & purification , Thymelaeaceae/chemistry , Wood/chemistry , Carbon-13 Magnetic Resonance Spectroscopy , Cell Line, Tumor , Flavonoids/chemistry , Humans , Laos , Proton Magnetic Resonance SpectroscopyABSTRACT
Objective: To study the chemical constituents of agarwood originating from Aquilaria crassna in Cambodia. Methods: The compounds were isolated and purified by silica gel column chromatography and semi-preparetive HPLC and so on. Their structures were identified by spectroscopic data. All compounds were tested for cytotoxic activities against two human cancer cell lines by MTT method. Results: Four compounds were isolated and elucidated as 6-methoxy-8-hydroxy-2-(2-phenylethyl) chromone (1), 6-methoxy-7-hydroxy-2-[2-(4-methoxyphenyl) ethyl] chromone (2), 7β,8β-epoxy-6α-hydroxy-5α-methoxy-5,6,7,8-tetrahydro-2-[2-(4- methoxyphenyl) ethyl] chromone (3), and rel-(1aR,2R,3R,7bS)-5,6-epoxy-7,8-dihydroxy-5,6,7,8-tetrahydro-2-[2-(4-methoxyphenyl) ethyl] chromone (4). Conclusion: Compound 1 is a new compound, while compounds 2-4 are isolated from this agarwood for the first time. Among them, compound 4 showed inhibitory activities against SGC-7901 and A549 cells.
ABSTRACT
Objective To study the chemical constituents of agarwood from Aquilaria crassna. Methods The compounds were isolated and purified by various column chromatographic techniques. Their structures were identified on the basis of spectral data and physicochemical properties. And the compounds were tested for α-glucosidase inhibitory activity by pNPG method. Results One new sesquiterpenoid along with two known chromones, which were determined as methyl crassicid (1), 8-chloro-6-hydroxy-2-(2- phenethyl) chromen-4-one (2), 8-chloro-6-hydroxy-2-[2-(4-methoxyphenyl) ethyl] chromen-4-one (3), were obtained from the ethyl acetate extract obtained from 95% ethanol extract of agarwood from A. crassna. Conclusion Compound 1 is a new sesquiterpenoid named sesquiterpenoid, which exhibited α-glucosidase inhibitory activity with IC50 value of 121.8 μg/mL.
ABSTRACT
Objective To study the chemical constituents of sesquiterpenoids of agarwood from Aquilaria crassna. Methods Seven squiterpenoids were isolated and purified by various column chromatographic techniques and HPLC method. The structures of the compounds were identified through the combined analysis of physicochemical properties and spectral data. The acetylcholinesterase and α-glucosidase inhibitory activity of compounds were evaluated by Ellman colorimetric method and pNPG method, respectively. Results Seven compounds were isolated from the ethyl acetate extract obtained from 95% aq. ethanol extract of agarwood from Aquilaria crassna and were identified as 2-[(2β,8β,8aα)-8,8a-dimethyl-1,2,3,4,6,7,8,8a-octahydro naphthalen-2-yl]-3- hydroxy-2-methoxpropanoic acid (1), 2-[(2β,8α,8aα)-8,8a-dimethyl-1,2,3,4,6,7,8,8a-octahydronaphthalen-2-yl] propane-1,2-diol (2), (1β,3α,4aβ,5β,8aα)-4,4a-dimethyl-6 (prop-1-en-2-yl) octahydronaphtha-lene-1,8a(1H)-diol (3), eremophila-9-en-8β,11-diol (4), eudesma-4-en-8,11-diol (5), eudesma-4-en-11,15-diol (6), and methyl-15-oxo-eudesmane-4,11 (13)-dien-12-oate (7). Moreover, compounds 1, 4 and 5 showed acetylcholinesterase inhibitory activity, and compound 5 exhibited α-glucosidase inhibitory activity.Conclusion Compound 1 is a new compound named as crasscid A, and compounds 1-3 and 7 are obtained from agarwood for the first time.
