A comparative study of the mineral elements in different medicinal plant parts of Daphne altaica Pall.

Daphne altaica Pall. is an important plant in traditional Chinese medicine. Mineral elements play an important role in the formation of active ingredients in medicinal plants. In this study, 14 mineral elements were quantitatively determined by inductively coupled plasma emission spectrometry using the roots, stems and leaves of D. altaica. The distribution variance of mineral elements between different organs were analyzed by statistical analysis methods such as single factor analysis of variance (ANOVA), correlation analysis (CA), principal component analysis (PCA) and cluster heat map. The results show that the mineral element contents in corresponding parts of D. altaica exhibited significant variation, with the order from highest to lowest being K > Ca > Mg > Fe > Al > Mn > Na > Zn > Sr > Cr > Ni > Cu > Pb > Mo. Among them, the highest content of mineral elements are K, Ca, Mg, Mn, Cu and Mo in leaves, and the stems contains more Zn, Sr, Cr and Ni, while the content of mineral elements Fe, Al, Na and Pb in roots is much higher than the other two organs. The ANOVA revealed significant variations in the mineral element content across different regions of D. altaica (p < 0.05). Based on single factor analysis of variance, different parts of D. altaica had different fingerprint of mineral elements, and the concentration of the same mineral elements in different parts had significant difference (p < 0.05). The principal component analysis (PCA) model showed that the cumulative variance contribution rate of first two principal components was 99.10%, in which Mn, Mg and Ca have higher load values, which is consistent with the results of bi-plot and cluster analysis. These results indicated that there were great differences in absorption and utilization of mineral nutrient elements between roots, stems and leaves of D. altaica, and there was significant correlation among mineral elements, indicating that there was a complex synergistic and antagonistic effect among the elements. At the same time, the discriminant analysis of the characteristic elements provided a scientific basis for the quality control of D. altaica.