Federal Research Centre for Forests-BFW, Department of Forest Genetics, Hauptstraße 7, A-1140 Vienna, Austria.
Phytochemistry. 2012 Nov;83:70-8. doi: 10.1016/j.phytochem.2012.06.001. Epub 2012 Jul 14.
Prunus africana--an evergreen tree found in Afromontane forests--is used in traditional medicine to cure benign prostate hyperplasia. Different bioactive constituents derived from bark extracts from 20 tree populations sampled throughout the species' natural range in Africa were studied by means of GC-MSD. The average concentration [mg/kgw/w] in increasing order was: lauric acid (18), myristic acid (22), n-docosanol (25), ferulic acid (49), β-sitostenone (198), β-sitosterol (490), and ursolic acid (743). The concentrations of many bark constituents were significantly correlated and concentration of n-docosanol was highly significantly correlated with all other analytes. Estimates of variance components revealed the highest variation among populations for ursolic acid (66%) and the lowest for β-sitosterol (20%). In general, environmental parameters recorded (temperature, precipitation, altitude) for the samples sites were not correlated with the concentration of most constituents; however, concentration of ferulic acid was significantly correlated with annual precipitation. Because the concentration of compounds in bark extracts may be affected by tree size, the diameter of sampled plants at 1.3m tree height (as proxy of age) was recorded. The only relationship with tree diameter was a negative correlation with ursolic acid. Under the assumption that genetically less variable populations have less variable concentrations of bark compounds, correlations between variation parameters of the concentration and the respective genetic composition based on chloroplast and nuclear DNA markers were assessed. Only variation of β-sitosterol concentration was significantly correlated with haplotypic diversity. The fixation index (F(IS)) was positively correlated with the variation in concentration of ferulic acid. Principal Components Analysis (PCA) indicated a weak geographic pattern. Mantel tests, however, revealed associations between the geographic patterns of bioactive constituents and the phylogenetic relationship among the populations sampled. This suggests an independent evolution of bark metabolism within different phylogeographical lineages, and the molecular phylogeographic pattern is partly reflected in the variation in concentration of bark constituents. The results have important implications for the design of strategies for the sustainable use and conservation of this important African tree species.
非洲朴树——一种常绿乔木，生长在 Afromontane 森林中——在传统医学中被用于治疗良性前列腺增生。本研究采用 GC-MSD 分析了来自非洲 20 个树种群的树皮提取物中的不同生物活性成分。按浓度[mg/kgw/w]从高到低依次为：月桂酸（18）、肉豆蔻酸（22）、正二十二烷醇（25）、阿魏酸（49）、β-谷甾醇（198）、β-谷甾醇（490）和熊果酸（743）。许多树皮成分的浓度呈显著正相关，正二十二烷醇的浓度与所有其他分析物高度显著相关。方差分量估计显示，熊果酸的种群间变异最大（66%），β-谷甾醇的变异最小（20%）。一般来说，记录的环境参数（温度、降水、海拔）与大多数成分的浓度无关；然而，阿魏酸的浓度与年降水量显著相关。由于树皮提取物中化合物的浓度可能受树木大小的影响，因此记录了 1.3 米树高处（代表年龄）采样植物的直径。唯一与树径相关的是与熊果酸呈负相关。基于叶绿体和核 DNA 标记，评估了浓度的变异参数与相应遗传组成之间的相关性，假设遗传变异较小的种群其树皮化合物的浓度变异也较小。只有 β-谷甾醇浓度的变异与单倍型多样性显著相关。固定指数（F(IS)）与阿魏酸浓度的变异呈正相关。主成分分析（PCA）表明存在较弱的地理模式。然而，Mantel 检验揭示了生物活性成分的地理模式与所采样种群的系统发育关系之间的关联。这表明不同系统发育谱系中树皮代谢的独立进化，并且分子系统地理学模式在一定程度上反映在树皮成分浓度的变异中。研究结果对设计可持续利用和保护这一重要非洲树种的策略具有重要意义。
