白木香叶与沉香树脂形成相关的指标性成分研究

Study on the Indicative Components between the Leaves of Aquilaria sinensis and Resin Involved in the Formation of Agarwood

目的应用气相色谱-质谱联用(GC-MS)技术结合多元统计分析,筛选白木香叶中与沉香树脂形成相关的指标性成分。方法以GC-MS法分析已结香和未结香的白木香叶三氯甲烷提取物,正交偏最小二乘法判别分析(OPLS-DA)对样品进行分组,变量权重(VIP)结合相关系数[P(corr)]筛选差异组分,自动质谱退卷积定性系统(AMDIS)结合保留指数(RI)鉴定差异组分。以GC-MS的选择性离子检测(SIM)模式测定差异组分油酸酰胺、芥酸酰胺含量。结果已结香和未结香白木香叶中,与贮存时长无关的差异组分为油酰酸胺、芥酸酰胺、三十二烷、α-香树脂醇和羽扇豆醇。油酸酰胺和芥酸酰胺线性范围分别为0.68~6.8μg·mL^(-1)(r=0.9993)和2.72~27.2μg·mL^(-1)(r=0.9997);平均加样回收率分别为99.9%(RSD=3.69%)和93.8%(RSD=3.23%)。未结香组油酸酰胺与芥酸酰胺的平均含量均高于各结香组,而且未结香组油酸酰胺含量明显高于化学试剂诱导组(P<0.05)。结论油酰酸胺和芥酸酰胺可作为白木香叶中与贮存时长无关、与沉香树脂形成相关的指标性成分,可为沉香的采收时间提供判断依据。

Objective To screen the indicative components between the leaves of Aquilaria sinensis and resin involved in the formation of agarwood based on gas chromatography-mass spectrometry(GC-MS) combined with multivariate statistical analysis. Methods The chloroform extracts of the leaves from A. sinensis with or without resin were analyzed by GC-MS,and the samples were grouped by orthogonal partial least squares discriminant analysis(OPLS-DA). Variable importance in projection(VIP)combined with correlation coefficient [P(corr)] was used to screen the differential components. Automated mass spectral deconvolution and identification system(AMDIS)coupled with retention index(RI)were used to identify the differential components. The selected ion monitor(SIM)mode of GC-MS was used to determine the contents of oleamide and 13-docosenamide in the leaves of A. sinensis.Results The different components unrelated to the storage time in leaves from two kinds of A. sinensis were oleamide, 13-docosenamide, dotriacontane, α-amyrin, and lupeol. The calibration curves were linear over the ranges of 0.68-6.8 μg·mL^(-1)(r=0.999 3)and 2.72-27.2 μg·mL^(-1)(r=0.999 7)for oleamide and 13-docosenamide,respectively. The sample recovery rates of oleamide and 13-docosenamide were 99.9%(RSD=3.69%)and 93.8%(RSD=3.23%),respectively. The average contents of oleamide and 13-docosenamide in non-resinous group were higher than that in agarwood-producing group. The oleamide content in non-resinous group was significantly higher than that in chemical stimulation group(P<0.05). Conclusion Oleamide and 13-docosenamide can be used as indicative components between the leaves of non-resinous and agarwood-producing Aquilaria tree which were independent of storage time,which can provide basis for the harvest time of the resin of A. sinensis.