HPLC-DAD-ESI-MS-Guided Study On 2-(2-Phenylethyl)Chromone Derivatives Of Agarwood Originating From Aquilaria Crassna In Cambodia

Agarwood,the resinous heartwood originating from the wounded tree of Aquilaria and Gyrinops species of Thymelaeaceae family,often presents in irregular blocks or flakes.At present,most of the agarwood circulated in the international are from Aquilaria sinensis,Aquilaria malaccensis,Aquilaria crassna,and Aquilaria filaria.The study of chemical composition and pharmacological activities of agarwood,which attracted much attention of researchers,mainly concentrate on the A.sinensis and A.malaccensis.Objective:The purpose of this study was to reveal the chemical constituents of agarwood from Aquilaria crassna in Cambodia and provide some theoretical guidance for the identification.At the same time,the cytotoxicity and acetylcholinesterase inhibitory activity of some monomeric compounds were tested,which could provide a theoretical basis for the development and utilization of agarwood produced in Cambodia.Methods:In this study,UPLC-MS,HPLC,and multiple spectral methods combined with published data comparison were used for chemical composition separation and identification.The separation of some special compounds such as2-(2-phenylethyl)chromone polymers and 2-(2-phenylethenyl)chromones,combining HPLC,TLC and other methods achieved a multiplied effect.Some compounds were evaluated for cytotoxicic and acetylcholinesterase inhibitory activities by MTT method and Ellman method,respectively.Results:Guided by HPLC-MS,HPLC and other methods,38 compounds were identified from the Et OH extract of agarwood originating from Aquilaria crassna in Cambodia.These compounds consisted of thirty-three 2-(2-phenylethyl)chromones(1-30),four sesquiterpenoids(31-34),one named zingerone(35).Among them,twelve compounds were identified as new compounds(1-10,14-15)and four compounds were identified as new naturally occurring compounds(18-20,33).Some compounds were assessed for the cytotoxic and acetylcholinesterase inhibitory activities by MTT method and Ellman method,respectively.The results revealed that compounds 9,10,11 a,11b,14,19,30 and 32 displayed different degrees of cytotoxicity.Compound 11 b is significantly superior to other compounds(against K562、SGC-7901,and A549).And compounds 4a,4b,8,11 b,12 and 13 exhibited weak inhibitory activities against acetylcholinesterase.Conclusion:In this study,sesquiterpene-2-(2-phenylethyl)chromone conjugates and2-(2-phenylethenyl)chromones were identified from agarwood originating from Aquilaria crassna in Cambodia.The chemical composition of agarwood in Cambodia was initially revealed,which provided a basis for the development and utilization of agarwood in Cambodia.At the same time,the separation method adopted can provide reference for the subsequent research on chemical components.