Phytochemical analysis of different Callicarpa species based on integrating metabolomics and chemometrics

Traditionally, Callicarpa species have been utilized their anti-inflammatory and hemostatic properties. Prominently featured species in the 2020 Edition of the Chinese Pharmacopoeia were Callicarpa nudiflora (CN), Callicarpa macrophylla (CM), Callicarpa formosana (CF), and Callicarpa kwangtungensis (CK), which were formulated into several medicinal preparations. Extensive applications led to the significant depletion of CN's wild resources. The management of germplasm resources was significantly disordered. Adulteration issues were also prevalent.

It is imperative that the study aims to identify alternative sources for CN and other pharmacopeial varieties and develop methods to distinguish different Callicarpa species.

Data were acquired using three mass spectrometry modes: Data Dependent Analysis (DDA), Data-Independent Analysis (DIA), and full mass spectrometry (MS). The DDA mode identified or inferred information on 54 compounds. The Full MS mode identified or inferred 74 compounds, including 20 that were previously unreported in Callicarpa. These compounds were confirmed using standards. The DIA mode did not facilitate identification due to missing precursor ion data. With metabolomics, 19 differential compounds were identified or inferred. Luteolin, chrysoeriol, and quercetin were selected as potential markers, integrating the 10 active compounds from network pharmacology.

Based on the relative abundance of these markers, it was proposed that Callicarpa giraldii Hesse ex Rehd. var. (CGHRV) and CM could serve as alternative resource species to CN, while CGHRV and Callicarpa giraldii Hesse ex Rehd. (CGHR) could substitute the pharmacopeial CM. Callicarpa longissimi (CLG) was suggested as an alternative to CK, while Callicarpa cathayana (CC) and Callicarpa rubella (CRL) could replace CF. Furthermore, the absence of certain compounds in CK presented a novel opportunity for the differentiation of various Callicarpa species.