Study on the Chemical Composition of Dwarf Lespedeza
There are about 60 species of Lespedeza plants (leguminous), mainly distributed in East Asia, northeastern Australia, and North America. Planting plants of the Lespedeza genus can usually be used to prevent soil erosion. There are 25 species of Lespedeza plants in China. Some types are used as traditional medicinal herbs, such as the Leaf Cutting Iron Broom (commonly known as Lespedeza cuneta), which has long been used in traditional Chinese medicine to treat dysentery, hepatitis, and protect the liver, kidneys, and lungs. Multiple types of chemical components have been found in plants of the Lespedeza genus, mainly flavonoids, including dihydroflavones, flavonol oxygen glycosides, flavonoid carbon glycosides, isoflavones, dihydroflavones pterocarpans、coumestan、homoisoflavanone、2-phenylbenzo-furans、 Lignin and other phenolic compounds. Dwarf Lespedeza (L. forrestii) is mainly distributed in Yunnan and Sichuan provinces of China. At present, there are no reports on the chemical composition of this plant. In order to further reveal the chemical composition of plants in the Lespedeza genus, the whole plant chemical composition of dwarf Lespedeza was studied for the first time. Meanwhile, in order to continue searching for compounds with high anti-inflammatory activity from plants, this study screened the chemical components in dwarf Lespedeza for anti-inflammatory activity.

Ten compounds were isolated and identified from the methanol extract of the entire plant of dwarf Lespedeza, among which compounds 1-5 were flavonol glycosides, 6-8 were flavonoid carbon glycosides, 9 were isoflavones, and 10 were dihydroisoflavones, all of which were first discovered in dwarf Lespedeza. Compounds 1-4 and 6-9 were found in the medicinal plant L. cuneta, indicating a close genetic relationship between dwarf Lespedeza and L. cuneta. In addition, compounds 1-10 were screened for anti-inflammatory activity, among which 8 and 10 can respectively inhibit the mRNA expression of inflammatory factors IL-6 and IL-1 β, demonstrating certain anti-inflammatory activity. Flavonoids are an important class of anti-inflammatory compounds. Related studies have found that compounds 1-4 and 6-9 can exert anti-inflammatory effects through different signaling pathways. This article shows that compound 8 can exert certain anti-inflammatory activity by inhibiting the mRNA expression of inflammatory factor IL-6, while compounds 1-4, 6, 7, and 9 have weaker effects on the mRNA expression of inflammatory factors IL-1 β, IL-6, and TNF – α. The anti-inflammatory activities of compounds 5 and 10 are reported for the first time in this article. This study reveals for the first time the chemical composition of dwarf Lespedeza in the genus Lespedeza, which can provide reference for the chemical identification and development of this plant.