Chemical composition and cytotoxic activity of tobacco pipe grass
Carpesium cernuum is a perennial herb of the Asteraceae genus Carpesium L. It is mainly distributed in northeastern, northern, central, eastern, southern, southwestern provinces, as well as northwestern Shaanxi, Gansu, and other regions. Especially in mountainous areas such as Sichuan and Guizhou in China, it is abundant and grows in roadside wastelands, mountain slopes, and ditch edges. Cigarettes are commonly used in folk medicine to treat diseases such as herpes zoster, mumps, oral erosion, trigeminal neuralgia, folliculitis, flat warts, acute viral conjunctivitis, and venomous snake bites. The plants of the Tianming Jing genus mainly contain compounds such as sesquiterpenes, monoterpenes, diterpenes, triterpenes, phenols, flavonoids, coumarins, lignans, steroids, etc. Among them, sesquiterpenes are the most representative and widely reported components in this genus of plants. Modern pharmacological studies have shown that this genus of plants has pharmacological effects such as anti-tumor, antibacterial, anti-inflammatory, insecticidal, and cytotoxic activities. In the early stage, our research group conducted chemical composition studies on tobacco pipe head grass and discovered five new sesquiterpenes. The isolated compounds were also studied for their anti leukemia and anti prostate cancer activities. The results showed that they could inhibit cancer cell proliferation by suppressing related signaling pathways. In order to obtain compounds with better biological activity, this study continued to investigate the chemical composition of the ethyl acetate extract of the 95% ethanol extract of tobacco tube grass, and tested the cytotoxic activity of the isolated compounds, providing a basis for the development and utilization of Tianming genus plants.

This article isolated and identified 10 compounds, including monoterpenes, diterpenes, and other compounds, from the ethyl acetate extract of the 95% ethanol extract of the entire tobacco pipe grass plant. Among them, compound 1 is a new compound. Compound 5 was previously developed by Japanese scholars as an anti ulcer drug Praenoxacin, but its specific effective site has not been determined, indicating that in the later study of the chemical activity of the Tianming Jing genus, the isolated diterpenoid compounds can be used for anti ulcer pharmacological activity research.

The cytotoxicity test of compounds 1 to 4 showed that compound 2 showed strong cytotoxicity to human breast cancer cell line MDA-MB-231, its IC50 value was 6.80 μ mol/L, and compounds 1, 3, and 4 showed moderate cytotoxicity. The extract of Hedysarum paniculatum can inhibit the proliferation of many cancer cells, but the IC50 value is the smallest in the human breast cancer cell MDA-MB-231, which provides a certain pharmacological basis for the treatment of breast cancer, suggesting that the extract of Hedysarum paniculatum can be used as a potential component of anti breast cancer drugs. Based on our previous research on the anti leukemia and anti prostate cancer effects of chemical components in tobacco tube grass, our research group found that its monomeric compounds can inhibit cancer cell proliferation by suppressing related signaling pathways. Therefore, tobacco tube grass has great research prospects in anti-tumor aspects, but currently the pharmacological activity research mainly focuses on the in vitro activity screening of monomeric compounds, and there is little research on in vivo efficacy evaluation, mechanism of action, and structure-activity relationship. Large amounts of monomeric compounds can be evaluated for in vivo efficacy, which provides important theoretical basis for the development of new anti-tumor drugs.