Abstract: In order to study the chemical constituents of Aquilaria crassna,nine 2-(2-phenylethyl）chromones were isolated by various column chromatographic techniques from the agarwood of Aquilaria crassna,and their structures were identified on the basis of spectroscopic data analysis as 6-methoxy-2-［2-(3′-hydroxy-4′-methoxyphenyl)ethyl］chromone (1),5-hydroxy-6-methoxy-2-［2-(3′-hydroxy-4′-methoxyphenyl)ethyl］chromone (2),tetrahydrochromone F (3),6-methoxy-2-［2-(3′-methoxy-4′-hydroxyphenyl)ethyl］chromone (4),6-methoxy-7-hydroxy-2-［2-(4′-methoxyphenyl)ethyl］chromone (5),6,7-dimethoxy-2-［2-(3′-hydroxy-4′-methoxyphenyl)ethyl］chromone (6),6,7-dimethoxy-2-［2-(4′-methoxyphenyl)ethyl］chromone (7),6-hydroxy-2-［2-(4′-hydroxyphenyl)ethyl］chromone (8),5-hydroxy-2-［2-(2′-hydroxyphenyl)ethyl］chromone (9).Compounds 2,3 and 5-9 were isolated from the agarwood of Aquilaria crassna for the first time.These compounds were tested for cytotoxicity by MTT method.Among them,compounds 1,2 and 4 showed weak cytotoxic activity.

Key words: Aquilaria crassna, chemical constituents, 2-(2-phenylethyl)chromone, cytotoxicity