The 2-(2-Phenylethyl) Chromone Conjugates And Their Bioactivities From Agarwood Of Aquilaria Walla

Agarwood is the resinous heartwood from wounded tree of the Aquilaria and Gyrinops species.The main components of agarwood are sesquiterpenoids and2-（2-phenylethyl）chromones.In our previous study,several unreported 2-（2-phenethyl）chromone derivatives were dectected during LC-MS analysis of the ethyl acetate extraction of agarwood of Aquilaria walla.In this study,the ethyl acetate extract of A.walla was selected as the experimental material,and systematically discover the2-（2-phenethyl）chromone conjugates with novel structure and biological activity,and to establish foundation for the quality identification and scientific utilization of agarwood of A.walla.Twenty-four compounds were isolated from agarwood of A.walla.Their structures were identified by by spectral methods and compared with published data,as follows:aquisinenone S（1）,wallone A（2）,aquilasesquit F-X（3–21）,aquilarene K（22）,rel-（5R,6R,7S）-5,6,7-trihydroxyl-2-（2-phenylethyl）-5,6,7,8-tetrahydro-4H-chromen-4-one（23）,6-hydroxy-7-methoxy-2-[2-（4′-hydroxyphenyl）ethyl]chromone（24）,including one new dimeric 2-（2-phenylethyl）chromones（1）,one new flavonoid-2-（2-phenethyl）chromone（2）,nineteen sesquiterpenoids-4H-chromones（3–21）,one new sesquiterpene（22）and one new 2-（2-phenylethyl）chromone（23）.The cytotoxic acyivities of compounds 1–21,23 and 24 were tested in vitro by MTT method.The results displayed that 1–4,7–10,12,13,15–17,21 and 23 show inhibitory activities against five human tumor cell lines.Compound 2 has obviously cytotoxic activities against human liver cancer cells BEL-7402 and human gastric cells SGC-7901with IC₅₀ values of 9.75 and 14.31μM,compound 12 has significant inhibitory activity on human cervical cancer cells Hela with IC₅₀ values of 15.31μM,compound 13 has significant inhibitory activity on human chronic myelogenous leukemia cells K562 and human cervical cancer cell Hela with IC₅₀ values of 9.76 and 13.31μM.Compounds 5,6,11,14 and 18–20 has no cytotoxic activity on five human tumor cells.Based on the above results,it can be speculated that the conjugates of 2-（2-phenylethyl）chromone with flavones or sesquiterpenes may significantly improve its cytotoxic activity.