Analysis of Nucleosides and Amino Acids in Different Parts of Lindera aggregata (Sims) Kosterm. from Different Habitats by UFLC-QTrap-MS/MS Combined with Multivariate Statistical Analysis

A method of ultra-fast liquid chromatography-triple quadrupole/linear ion trap tandem mass spectrometry (UFLC-QTrap-MS/MS) was established for simultaneous determination of 11 nucleosides and 14 amino acids in Lindera aggregata (Sims) Kosterm., which combined with multivariate statistical analysis to evaluate the quality of different medication parts of Lindera aggregata (Sims) Kosterm. from different habitats. The gradient separation was performed on a Waters XBridge Amide column (2.1 mm×100 mm×3.5 μm) with 0.2% formic acid in water (A) and 0.2% formic acid in acetonitrile (B) as the mobile phase, and the mass spectrometric detection was carried out in electrospray positive ion mode under multiple reaction monitoring (MRM)mode. The samples of different habitats and medication parts were comprehensively evaluated by entropy weight ANOVA, PCA, OPLS-DA, HCA, TOPSIS and GRA according to the contents of 25 target constituents. All of the analytes had good linearity in the range of tested concentration with the correlation coefficient not less than 0.992 4. The average recoveries were between 94.86% and 106.47%, with the relative standard deviation (RSD) less than 4.55%. The analysis results showed that there were significant variations among the different medication parts of Lindera aggregata (Sims) Kosterm. samples. The contents of nucleosides and amino acids in tuber were significantly higher than those in taproot and leaf (p<0.05). In terms of nucleoside, tuber had the highest content with an average content of 74.786 μg/g, followed by leaf of 55.401 μg/g and taproot of 36.290 μg/g. The highest content of amino acid was found in tuber with an average content of 50.850 μg/g, followed by the taproot and leaf with an average contents of 43.213 μg/g and 35.676 μg/g, respectively. The samples collected from different parts of Lindera aggregata (Sims) Kosterm. in different regions were classified into three clusters by HCA and PCA according to the contents of nucleotides and amino acids detected. The classification results were satisfactory, indicating that there were obvious differences in the content of nucleosides and amino acids in different parts of the samples. Six different chemicals, namely uridine, alanine, cytosine, xanthine, adenine and guanine, were obtained by VIP co-screening in OPLS-DA model analysis. Comparing the maximum difference values of TOPSIS and GRA, it was found that the maximum difference value of r_i in GRA was 12.08%, while C_i in TOPSIS was 53.23%. This method is simple, sensitive and accurate, which provides a reliable and effective technique for the quality control of Lindera aggregata (Sims) Kosterm..