Positions of PCA scores (PC1, PC2) of eight <i>G</i>. <i>elata</i> cultivars, based on amino acids, nucleosides, S-(4-hydroxybenzyl)-glutathione, gastrodin, parishin derivatives compound content.

<p>The four compounds (gastrodin, parishin E, parishin B, parishin) were quantified by comparison with external standards, while the other parishin derivatives were quantified by comparison with an equivalent of parishin, and the other compounds were compared with an equivalent of gastrodin. Percentages in parentheses represent principal component variance. Numbers in figure B and C correspond to cultivar number in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150647#pone.0150647.t001" target="_blank">Table 1</a>. (A) Sore scatter plot; (B) loading plot based on different area;(C)loading plot based on different cultivars. All the quantitative data was acquired by UPLC-ESI-triple quadrupole ion MS.</p

Recovery of four standards in the extraction of GE (n = 3).

<p>Recovery of four standards in the extraction of GE (n = 3).</p

Characterization of constituents extracted from gastrodia by ESI- linear ion trap high-resolution MS.

<p>Characterization of constituents extracted from gastrodia by ESI- linear ion trap high-resolution MS.</p

Intra- and inter-day precision of four standards by HPLC.

<p>Intra- and inter-day precision of four standards by HPLC.</p

<i>G</i>. <i>elata</i> cultivars used in this study.

<p><i>G</i>. <i>elata</i> cultivars used in this study.</p

The regression equation, LOD and LOQ of the four standards using the optimized method for calibration.

<p>The regression equation, LOD and LOQ of the four standards using the optimized method for calibration.</p