Analysis of Chemical Composition of Ethanol Extract of Bairuicao Based on UPLC-Q-TOF-MS/MS
Bairui grass is the dried whole plant of Thesium chinense Turcz. in the Santalaceae family. It has a slightly bitter, astringent, and pungent taste, and a cold nature. It has the effects of clearing heat, reducing inflammation, stopping cough, resolving phlegm, and reducing fever. Modern pharmacological studies have shown that Bairui grass has analgesic, antibacterial, and anti-inflammatory effects, and is widely used to treat diseases such as pneumonia, tonsillitis, and upper respiratory tract infections. Bai Rui Cao, as a folk herb, was included in the book “Anhui Chinese Herbal Medicine” in 1975. It was first included in the 1977 edition of the Chinese Pharmacopoeia and is now included in the 2003 edition of the “Quality Standards for Chinese and Ethnic Medicinal Materials in Guizhou Province”.
According to literature reports, Bai Rui Cao mainly contains active ingredients such as flavonoids, alkaloids, and organic acids. Zou et al. isolated and purified 10 flavonoid compounds from Bai Rui Cao’s ethanol extract through physical and chemical constant determination and spectral analysis. Wang et al. isolated three alkaloid components from Bai Rui Cao’s total biomass, namely N-methyl quercetin, quercetin, and sophocarpine. However, despite progress in chemical composition analysis, the understanding of the chemical composition of Platycodon grandiflorus is still limited to flavonoids and a few alkaloids, and there is a lack of systematic research on the active ingredients in Platycodon grandiflorus.
UPLC-Q-TOF-MS/MS analysis technology is a widely used qualitative determination method in the field of traditional Chinese medicine component research. It combines the efficient chromatographic separation ability of UPLC and the high sensitivity of Q-TOF high-resolution mass spectrometry, and can quickly perform qualitative analysis on complex components of Chinese herbal medicine. Therefore, this study used UPLC-Q-TOF-MS/MS technology to systematically analyze the chemical components of the alcohol extract of Bai Rui Cao, which is of great significance for clarifying the active substance basis of Bai Rui herb and ensuring the safety and effectiveness of clinical medication.

 

In this study, a total of 54 chemical components were identified from the ethanol extract of Atractylodes macrocephala, including 16 flavonoids such as astragaloside, 10 alkaloids such as quercetin, 5 diterpenes such as steviol glycosides, 5 organic acids such as succinic acid, and other compounds. Among them, 6 compounds such as sophocarpine and oxymatrine were compared with reference standards, and the remaining components were speculated and identified through secondary mass spectrometry fragment ion binding with relevant literature. This research provides a theoretical basis for studying the pharmacological effects and evaluating the active ingredient effects of Atractylodes macrocephala.
It was found from the alcohol extract of Bai Rui Cao that the active ingredients in Bai Rui Cao alcohol extract are mainly flavonoids and alkaloids. Among them, the 14 identified compounds belong to flavonols such as amygdalin and rutin, which have many important biological activities and pharmacological effects, such as anti-tumor, free radical scavenging, detoxification and anti-inflammatory, and immune enhancement; The five alkaloid compounds belong to the quinoline alkaloids such as matrine and oxymatrine, which have various biological activities such as anti-tumor, anti-inflammatory, antiviral, antibacterial, and immunosuppressive. These components work together and interact with each other to exert the effects of clearing heat, detoxifying, antibacterial, and anti-inflammatory properties of Bai Rui Cao, and are therefore known as “plant antibiotics”. In addition, through the analysis of the fragmentation pattern of alkaloids in the alcohol extract of Bai Rui Cao, it was found that quinoline alkaloids have a common m/z 150.1282 characteristic fragmentation fragment in the positive ion mode; Flavonoids exist in the form of [M+H]+and [M+Na]+peaks in the positive ion mode, and are prone to form quasi molecular ion peaks of [M-H] – in the negative ion mode. The mass spectrometry characteristics of flavonoid compound cleavage include the formation of glycoside ions and the removal of CO and H2O from sugar chains. m/z 163.0027 and 151.0320 are characteristic fragment ions produced by flavonoid alcohol glycoside cleavage, while diterpenoid compound cleavage mainly involves continuous sugar chain removal. At the same time, 32 chemical components, including oxymatrine, quercetin-7-O-glucoside, kaempferol-3-O-rutinoside-7-O-glucoside, were identified for the first time from the ethanol extract of Platycodon grandiflorus. These chemical components have not yet been reported in the ethanol extract of Platycodon grandiflorus, but further identification of these compounds is needed in the future.
This study used UPLC-Q-TOF-MS/MS technology to analyze the alcohol extract of Atractylodes macrocephala. Based on the molecular formula information and secondary fragment ions of the compounds, combined with comparison with reference standards and literature, the chemical composition of Atractylodes macrocephala alcohol extract was systematically analyzed, providing reference for further exploration of the pharmacological basis and mechanism of action of Atractylodes macrocephala.