Lagalante Anthony F, Montgomery Michael E
Worthington Scranton Campus, The Pennsylvania State University, 120 Ridgeview Drive, Dunmore, Pennsylvania 18512, USA.
J Agric Food Chem. 2003 Apr 9;51(8):2115-20. doi: 10.1021/jf021028s.
A sampling method for determining the volatile terpenoid composition from single needles of seven Tsuga species was developed using headspace solid-phase microextraction (SPME). A reproducible sampling method for the volatile components was generated by examination of sample storage, method of needle cutting, and headspace sampling duration. Following SPME collection of the volatile compounds from the seven Tsuga species, gas chromatography/ion-trap mass spectrometry was used to identify 51 terpenoids present in the needle headspace. A semiquantitative method was devised to express individual terpenoid amounts as a percentage of all of the identified peaks in the chromatogram. The semiquantitative results permitted facile interspecies comparison using principal component analysis. Two components were able to account for 90% of the variance and were interpreted as a "species" component and a "resistance/susceptibility" component. Three interspecies groupings were evident from the principal component analysis: (1) Tsuga canadensis and Tsuga caroliniana; (2) Tsuga chinesnsis, Tsuga diversifolia, Tsuga heterophylla, and Tsuga sieboldii; and (3) Tsuga mertensiana. The finding that T. mertensiana was grouped alone and far removed from the other species adds to the morphological evidence that this species should be segregated from other Tsuga.
采用顶空固相微萃取（SPME）技术，开发了一种从七种铁杉属植物的单针叶中测定挥发性萜类成分的采样方法。通过考察样品储存、针叶切割方法和顶空采样持续时间，建立了一种可重复的挥发性成分采样方法。从七种铁杉属植物中通过SPME收集挥发性化合物后，采用气相色谱/离子阱质谱法鉴定了针叶顶空中存在的51种萜类化合物。设计了一种半定量方法，将各萜类化合物的含量表示为色谱图中所有鉴定出的峰的百分比。半定量结果允许使用主成分分析进行简便的种间比较。两个成分能够解释90%的方差，分别被解释为“物种”成分和“抗性/易感性”成分。主成分分析显示出三个种间分组：（1）加拿大铁杉和卡罗来纳铁杉；（2）中国铁杉、台湾铁杉、异叶铁杉和日本铁杉；（3）高山铁杉。高山铁杉单独分组且与其他物种相距甚远，这一发现进一步补充了形态学证据，表明该物种应与其他铁杉属物种区分开来。
