Research on the Chemical Components and Antibacterial Activity of Guizhou Tianming Jing
The genus Carpesium in the Asteraceae family is a perennial herb with approximately 21 species worldwide, with a few species distributed in Eurasia and the majority in central Asia. Especially in the southwestern region of China, there are abundant plant resources. Among them, Carpesium, tobacco tube grass, and golden ear have been listed as legally recognized medicinal plants in China. Carpesium faberi in Guizhou has long been used as a folk medicine due to its hemostatic, antiparasitic, anti-inflammatory, and detoxifying properties. According to literature reports, at least 277 compounds have been isolated from plants of the Tianming Jing genus, including terpenes, flavonoids, phenols, steroids, etc. Among them, 37 compounds were isolated from Guizhou Tianming Jing, with sesquiterpenes being its main active ingredient. Pharmacological studies have shown that sesquiterpenes have various biological activities such as anti-tumor, anti malaria, anti-inflammatory, and antibacterial effects. In recent years, the activity reports of Guizhou Tianming Jing mainly focus on anti-tumor and anti-inflammatory activities, and its antibacterial activity has not been reported yet. In order to promote the comprehensive development and utilization of Tianming Jing plant resources, this study conducted chemical composition research on the whole plant of Tianming Jing collected from Kaili, Guizhou, and tested the antibacterial activity of the obtained compounds.

Using various chromatographic methods, 14 compounds were isolated and identified from the Guizhou produced Tianming Jing, as shown in Figure 1, including sesquiterpenes, diterpenes, steroids, and other components. Compounds 2 and 7-14 were obtained from this plant for the first time. Screening for antibacterial activity of isolated compounds. Using the double dilution method, the antibacterial activity of the compound against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, and Candida albicans was determined. The strain in logarithmic growth phase was used, and all samples were dissolved in DMSO to prepare a drug solution of 15.36mg/mL. The activity test results showed that compound 1 had weak antibacterial activity against Bacillus subtilis, with a MIC value of 256 µ g/mL. Compounds 10 and 6 showed weak activity against Candida albicans, with a MIC value of 128 µ g/mL for compound 10 and 128 µ g/mL for compound 6. The remaining compounds did not show antibacterial activity. This research has enriched the chemical composition and biological activity of Guizhou Tianming Jing, providing reference materials for its further research and development.