The Comprehensive Profiling of the Chemical Components in the Raw and Processed Roots of Scrophularia ningpoensis by Combining UPLC-Q-TOF-MS Coupled with MS/MS-Based Molecular Networking

Scrophulariae Radix (SR), the dried root of <i>Scrophularia ningpoensis</i> Hemsl (<i>S. ningpoensis</i>), has been extensively used as traditional Chinese medicine for thousands of years. However, since the mid-20th century, the traditional processing technology of <i>S. ningpoensis</i> has been interrupted. Therefore, ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry technology, together with a Global Natural Product Social Molecular Networking (GNPS) method, was applied to comprehensively analyze the characteristic changes and mutual transformation of chemical constituents in the differently processed roots of <i>S. ningpoensis</i>, as well as to scientifically elucidate the processing mechanism of differently processed SR. As a result, a total of 149 components were identified. Notably, with the help of the GNPS data platform and MS² fragment ions, the possible structures of four new compounds (<b>47</b>, <b>48</b>, <b>50</b>, and <b>73</b>) were deduced in differently processed SR samples, in which <b>47</b>, <b>48</b>, and <b>50</b> are iridoid glycosides, and <b>73</b> is a phenylpropanoid glycoside. Five cyclopeptides (<b>78</b>, <b>86</b>, <b>97</b>, <b>99</b>, and <b>104</b>) derived from leucine (isoleucine) were identified in SR for the first time. The heatmaps analysis results indicated that leucine or isoleucine may be converted to cyclopeptides under the prolonged high-temperature conditions. Moreover, it is found that short-time steaming can effectively prevent the degradation of glycosides by inactivating enzymes. This study provides a new and efficient technical strategy for systematically identifying the chemical components, rapidly discovering the components, and preliminarily clarifying the processing mechanism of <i>S. ningpoensis</i>, as well as also providing a scientific basis for the improvement of the quality standards and field processing of <i>S. ningpoensis.</i>