Chemical Constituents And Pharmacological Activities Of Ilex Rotunda And Sapium Discolor

Characterized by novel structures and diverse biological activities,natural products are important sources for the discovery of drug lead compounds,drug candidates,and innovative drugs.Searching for active natural products with novel structures from traditional Chinese medicine has always been one of the important directions of natural medicinal chemistry research.In this paper,we conducted a comprehensive study of the chemical constituents and pharmacological activity of the dried bark of Ilex rotunda(the traditional Chinese medicine name is “Jiu-Bi-Ying”)and Sapium discolor to obtain active compounds with novel structures and clarify their pharmacodynamic material basis.Fifty compounds were isolated from the 95% ethanolic extracts of I.rotunda and S.discolor by thin-layer chromatography(TLC),column chromatography,and high performance liquid chromatography(HPLC).Their structures were elucidated through extensive spectroscopic analysis and comparison with the literature data.The 30 compounds isolated from I.rotunda consisted of 15 triterpenoids(A1–A15)and 15 phenolic derivatives(A16–A30),among which compounds A1(3β,23α-dihydroxyurs-12,19(29)-dien-28-oic acid),A16–A20(rotundosides A–E)and A25–A26(rotundarpenes A–B)are new compounds.Structural modification was carried out on the abundant component rotundic acid(A2)in I.rotunda,and a total of 30 derivatives(B1–B30)were obtained.The 20 compounds isolated from S.discolor comprised 9lignoid oligomers(S1–S9)and 11 other compounds(S10–S20),among which compounds S1(discolorol A)and S10(discoloroside A)are new compounds.On the basis of the traditional efficacy of I.rotunda,we conducted research on its anti-inflammatory activity.The anti-inflammatory properties of the 60 compounds that were isolated and structurally modified from I.rotunda were evaluated using modified nitric oxide(NO)production in lipopolysaccharide(LPS)-induced leukemia cells in a mouse macrophage(RAW264.7)method.As a result,20 compounds showed obvious anti-inflammatory activity in vitro,among which compounds A25 and A26 showed significant anti-inflammatory activity in vitro(NO inhibition rate in 10 μM: 95.9±4.8%and 80.3±5.3%).The structure–activity relationship of rotundic acid derivatives was summarized by the NO inhibition rate of the compounds.It was found that the introduction of aromatic groups at the C-3 and C-23 sites or at the C-28 site of rotundic acid promoted the anti-inflammatory activity,while the introduction of hydrazone groups led to the cytotoxic activity.Quantitative real-time fluorescence reaction experiments(q RT-PCR)showed that compounds A25 and A26 could reduce the transcriptional levels of inflammatory factors IL-1β and IL-6 in cells in a concentration-dependent manner.According to the previous activity study of S.discolor,we found that the ethanolic extract of S.discolor showed strong lipid-uptake activity.Thus,we conducted further research on its lipid-lowering active components.The lipid-uptake activity of some compounds isolated from S.discolor were evaluated using a screening model of the uptake of red fluorescently labeled low-density lipoprotein(DIi-LDL)by human hepatocellular carcinomas(Hep G2).As a result,compounds S1–S4 showed mild lipiduptake activity,and compounds S5,S6,S12,and S13 showed significant lipid-uptake activity.