Laboratory of Plant Biotechnology, National Institute of Applied Science and Technology, Centre Urbain Nord, Tunis Cedex, Tunisia.
Chem Biodivers. 2012 Jul;9(7):1272-85. doi: 10.1002/cbdv.201100344.
Volatiles from 14 wild Tunisian populations of Thymbra capitata (=Thymus capitatus Hoffmanns. et Link=Coridothymus capitatus Rchb.f.), sampled in five ecological areas (sub-humid, upper semi-arid, mean semi-arid, lower semi-arid, and upper arid areas) were analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) techniques. Thirty-nine constituents representing 94.2 to 99.5% of the total oil were identified. Carvacrol (38; 51.1-75.9%), p-cymene (13; 3.7-15%), γ-terpinene (12; 1.4-11.9%), and trans-β-caryophyllene (22; 2.9-4.6%) are the major compounds. A significant variation among populations and population's bioclimatic stage for the majority of compounds was shown. The chemical population structure, estimated using a principal-component analysis (PCA) and an unweighted pair group method with arithmetic mean (UPGMA) cluster analysis performed on all populations and compounds and based on Euclidean distances among populations, was high. Both methods allowed separation of the populations into distinct groups defined rather by minor than by major compounds. The spatial compound distribution is linked to ecological factors, indicating that local selective environmental factors influence chemical-composition diversity. Conservation strategies should involve all populations because of their low size and their high level of destruction. Populations exhibiting particular compounds other than the major ones should first be protected. In situ conservation of populations should be accomplished appropriately according to bioclimate.
对来自突尼斯 14 个野生 Thymbra capitata（=Thymus capitatus Hoffmanns. et Link=Coridothymus capitatus Rchb.f.）种群的挥发物进行了采样分析，这些种群分布在五个生态区（半湿润、上半干旱、中半干旱、下半干旱和上干旱区），并采用气相色谱（GC）和气相色谱/质谱（GC/MS）技术进行了分析。鉴定出了 39 种成分，占总油量的 94.2%至 99.5%。香芹酚（38；51.1-75.9%）、对伞花烃（13；3.7-15%）、γ-萜品烯（12；1.4-11.9%）和反式-β-石竹烯（22；2.9-4.6%）是主要成分。大多数化合物在种群之间和种群的生物气候阶段都存在显著差异。使用主成分分析（PCA）和基于欧式距离的无加权对群平均法（UPGMA）聚类分析对所有种群和化合物进行分析，估计了化学种群结构，结果表明种群结构高度分化。这两种方法都可以将种群分为不同的组，这些组主要由次要化合物而不是主要化合物定义。空间化合物分布与生态因素有关，表明局部选择性环境因素影响化学组成多样性。保护策略应涉及所有种群，因为它们的种群规模较小，破坏程度较高。应首先保护那些表现出除主要化合物以外的特殊化合物的种群。根据生物气候条件，应适当进行种群的就地保护。
