Study On The Bioactive Components From The Roots Of Atalantia Buxifolia

Atalantia buxifolia (Poir.) Oliv.(Rutaceae) belongs to the genus of Atalantia, which is commonly known as the thorny, evergreen shrub. In Hainan province of China, the roots of A. buxifolia are used as traditional folk medicine for the treatment influenza, cough, malaria, and stomachache by the people of Li nationality. Previously phytochemical studies showed that meliacanes and acridone alkaloids were major constituents of A. buxifolia, which were reported that possession of insects antifeeding activities and possession of cytotoxicity, respectively. In an effort to provide scientific proof for further development of A. buxifolia and search for new bioactive constituents, chemical constituents and bioactivities of the roots of A. buxifolia were studied systematically.Twenty compounds were isolated from the ethanol extract of the roots of A. buxifolia by column chromatography, and their structures were identified by physicochemical and spectroscopic methods (including MS, IR, UV, ID and2D-NMR, etc) as6-deacetyl-severinolide (1), severinolide (2), acetyl-isoepiatalantin (3),7-isovaleroylcycloepiatalantin (4), cycloepiatalantin (5),7-isovaleroylcycloseverinolide (6), atalantin (7),7-deacetyl-severinolide (8), syringaresinol (9), buxifoliadine A (10),1,3-dihydroxy-2,4-diprenylacridone(11),5-hydroxy-N-methylseverifoline (12), buxifoliadine B (13), N-methylatalaphylline (14), atalaphylline (15), atalafoline (16), aurapten (17), coniferyl aldehyde(18), α-amyrin (19), and lupeol (20), respectively. Compound1was a new tetranortriterpenoid, and compound8was a new natural product. Compounds9and18were isolated from the roots of A. buxifolia for the first time.The cytotoxicities of compounds1-18were evaluated in vitro using the MTT method. Compounds10and17showed cytotoxic activities towards human hepatoma (SMMC-7721), and compound12showed significant inhibitory activity towards chronic myelogenous leukemia (K562).