Study on the Chemical Composition and Anti inflammatory Activity of Sheep Horn and Stubborn Stem
Strophanthus divaricatus (Lour.) Hook Et Arn., also known as sheep horn twisted, carp olive, goat horn, is a plant of the Apocynaceae family in the Strophanthus genus. It is mainly distributed in provinces such as Hainan, Yunnan, Guizhou, Guangdong, and Fujian in China, as well as in South Asian countries such as Laos and Vietnam. It is wild in hilly and mountainous areas, roadside sparse forests, or hillside shrubs. The whole plant of Yangjiaoao is poisonous and used as a medicinal cardiac stimulant. It can be used to treat diseases such as arteriosclerosis, sprains, rheumatoid arthritis, snake bites, etc. It can also be used as an insecticide in agriculture. Research has shown that Yangjiaoao mainly contains cardiac glycosides, as well as chemical components such as sesquiterpenes, triterpenes, and lignans. The extract of Yangjiaoao has cardiac strengthening, antibacterial, antioxidant, and insecticidal effects, and cardiac glycosides have biological activities such as anti-tumor and cardiac strengthening. In order to further improve the basic research on the chemical substances of Yangjiaobao, and further explore the chemical components of this plant and its anti-inflammatory activity, this study used silica gel, Sephadex LH-20 gel and other chromatographic separation technologies to separate the ethyl acetate extract of the ethanol extract of Yangjiaobao stem, and used LPS induced mouse monocyte macrophage RAW264.7 cell inflammation model to test the anti-inflammatory activity of its chemical components in vitro.

This study isolated and identified 13 compounds (1-4 and 6-13) from sheep horn stems for the first time. Among them, literature reported that pentacyclic triterpenoid ivy saponins (1) have anti-tumor, antidepressant, and antibacterial activities, and further research is needed. The anti-inflammatory activity screening results of LPS induced mouse monocyte macrophage RAW264.7 model showed that turpentine (5) had significant anti-inflammatory activity, with an IC50 value of 18.09 ± 1.09 μ M. This study enriches the compound types of Yangjiaoao and provides a basis for its anti-inflammatory activity research.