Study On The Characteristic Constituents Of Four Agarwood From Different Origin Plant

Agarwood is not a plant,but a dark resinous and aromatic heartwood produced by the injury plant of Aquilaria or Gyrinops.It is a rare perfume and precious medicinal material with a long history and wide use.Agarwood has attracted widespread attention because of its rare,precious and extensive use.However,due to the different origin plants and the formation time of agarwood,there are great differences in quality,and there is no perfect rapid detection and evaluation system at present.Therefore,the characteristic components of four agarwood from different origin plant were separated and identified,for the characteristic differences of agarwood.At the same time,the mass spectrometry fragmentation regular of 2-(2-phenylethyl)chromones were found.To establish a rapid method for the identification of 2-(2-phenylethyl)chromones,and to analyze the different time of agarwood formation.Through various column separation techniques and spectroscopic analysis,eighteen sesquiterpenes(1-18)and fourteen 2-(2-phenylethyl)chromones(19-32)were isolated and identified from agarwood of Aquilaria sinensis,five sesquiterpenes(37-41)and fifteen chromones(33-36,42-52)were isolated and identified from agarwood of Aquilaria crassna,fourteen sesquiterpenes(53,57-69)and nine 2-(2-phenylethyl)tryptones(54-56,70-75)were isolated and identified from agarwood of Gyrinops salicifolia,ten sesquiterpenes(76-84)and six 2-(2-phenylethyl)chromones(85-90)were isolated and identified from agarwood of Gyrinops walla.According to the analysis and comparison,the characteristic components among the four agarwood of different origin plants all contain the common components of agarwood,but there are also different characteristic components.Based on the above results,the mass spectrometry regular of chromones was systematically studied,and the mass spectrometry database of chromones was established,which laid a foundation for the identification of chromones in agarwood.The fragmentation regularity of mass spectra(MS)is as follow:2-(2-phenylethyl)chromone is composed of a chromone moiety and phenyl moiety,connected by CH2-CH2 group.In the MS2 spectrum,CH2-CH2 bond breaks and benzyl ions are detected,and the typical ions included 151[C7H5+2OCH3]+,137[C7H5+OH+OCH3]+,121[C7H6+OCH3]+ and 107[C7H6+OH]+.In the absence of substitution,The molecular weights of the basic skeletons of THPECs,EPECs,DEPECs and FTPECs were 254,268,282 and 250,respectively.The present of the ions[M+H-18]+and[M+H-18-18]+ was proposed to be THPECs.When both ions[M+H-18]+and[M+H-28]+were observed in the spectrum,EPECs was deduced.If only[M+H-28]+was detected,it would be DEPECs.FTPECs only gave the peaks of benzyl ions and chromone moiety ions in the MS2 spectrum.The characteristic fragmentation behavior of DEPECs and EPECs,and the methods to distinguish these four types of chromones by MS analysis were described for the first time.And the fragmentation regularity of mass spectra(MS)used to distinguish and identify the 2-(2-phenylethyl)chromones rapidly.Based on the mass spectrometry fragmentation regular and database of 2-(2-phenylethyl)chromones,a total of fifty-six chromones,including seven 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromones(THPECs),five 5,6-epoxy-2-(2-phenylethyl)chromones(EPECs),seven 5,6:7,8-diepoxy-2-(2-phenylethyl)chromones(DEPECs)and thirty-seven 2-(2-phenylethyl)chromones of flidersia type(FTPECs),were characterized by HPLC-MS in three agarwood(from Aquilaria crassna)induced by artificial holing with different holing time.In addition,it was found that the relative contents of DEPECs and EPECs were down-regulated,while the relative contents of THPECs and FTPECs were up-regulated for the samples from two,four and five years of the agarwood formation time.With the increase of the agarwood formation time,the relative contents of the six FTPECs presented roughly upward.These results could be provided a reference for the length of formation time.