Analysis of Composition Differences in Ligustrum lucidum before and after Wine Production Based on Multivariate Statistical Analysis
Ligustrum Lucidum Ait. is a dried and mature fruit of the Oleaceae plant Ligustrum Lucidum Ait. The processing of Ligustrum Lucidum Ait basically inherits the ancient processing methods, mainly for use after purification, steaming with wine, and stewing with wine. Giving birth to female virgins not only nourishes the liver and kidneys, but also tends to clear the liver and improve vision, nourish yin and moisten dryness. Alcohol not only alleviates the cooling and slippery nature of female virgins, but also enhances their liver and kidney nourishing effects. The fundamental reason for the changes in the efficacy of Ligustrum lucidum may be the changes in chemical composition during the production process of Ligustrum lucidum wine. The quality control and evaluation of Ligustrum lucidum are mostly based on fingerprint spectra, focusing on changes in several known components, identifying the chemical composition of processed products, and using component identification combined with multivariate statistical analysis of the chemical composition of Ligustrum lucidum. Lack of a comprehensive and rapid analysis method to systematically analyze the chemical composition of Ligustrum lucidum wine before and after production.

Mass spectrometry based molecular networks are a novel method for identifying the chemical components of traditional Chinese medicine. Compounds with similar chemical structures have similar mass spectrometry fragments, which can be automatically aggregated into molecular networks through data processing in GNPS to quickly identify different categories of compounds. Moreover, by setting groups, the chemical composition characteristics of traditional Chinese medicine samples with different origins, medicinal parts, and processing methods can be visualized on the pie chart of the molecular network. Therefore, this technology can be used to identify the chemical composition of different processed products of traditional Chinese medicine. Multivariate statistical analysis is a widely used analytical method for identifying differential chemical components in traditional Chinese medicine. The combination of multivariate statistical analysis and molecular network can be used to identify the chemical components of traditional Chinese medicine, screen for differential chemical components, and obtain more intuitive and accurate results.
This study integrated UPLC Orbitrap MS technology, molecular network technology, and combined principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) to analyze the chemical composition of Ligustrum lucidum before and after wine production, exploring the effect of wine production on the chemical composition of Ligustrum lucidum. It is a new and reasonable strategy for distinguishing chemical components in raw Ligustrum lucidum and wine Ligustrum lucidum and screening differential chemical components, providing reference for the material basis research of Ligustrum lucidum and its processed products.

This study established a comprehensive analysis method based on UPLC Orbitrap MS technology, mass spectrometry molecular network technology, and multivariate statistical analysis technology to identify the chemical composition of raw and wine aged Ligustrum lucidum, search for differential chemical components, and explore the changes in the material basis of Ligustrum lucidum before and after wine production. A total of 42 chemical components were identified, including iridoid glycosides, phenylethanoid glycosides, flavonoids, and triterpenoids. Through molecular network combined with multivariate statistical analysis, it was found that there were significant differences in the chemical composition of raw and wine aged samples of Ligustrum lucidum. The screened differential components included Ligustrum lucidum glycosides, Ligustrum lucidum glycosides, Rhodiola rosea glycosides, Rutin glycosides, Olive bitter glycosides, etc.

The combination of molecular network technology and high-resolution mass spectrometry qualitative analysis has certain advantages compared to traditional single mass spectrometry qualitative methods. Traditional qualitative analysis can only compare with the information of known compounds in the database, provide possible mass spectrometry information, and obtain information of a single compound, making it difficult to analyze unknown compounds. Molecular network technology can aggregate possible compounds of the same type with the same fragment into the same network based on mass spectrometry information, and intuitively display the differences in chemical composition between raw and processed Chinese medicine products based on the proportion of pie charts in the molecular network. Combining molecular network technology with multivariate statistical analysis techniques can accurately screen chemical markers between raw products.
The results of this study provide theoretical basis for the quality evaluation and quality control of raw and processed products of traditional Chinese medicine Ligustrum lucidum, and provide reference for clarifying the material basis of changes in the efficacy of Ligustrum lucidum wine before and after production. In addition, the comprehensive analysis method established in this study for the chemical composition of Ligustrum lucidum can provide a new analytical strategy for rapidly identifying the chemical components of other processed products and traditional Chinese medicine formulas.