Studies On The Chemical Constituents From Clausena Emarginata And Their Antitumor Activities

Clausena emarginata is a bush of the genus Clausena in the citrus family,Rutaceae.Mainly distributed in Yunnan,Guangxi and other southern part of China.The roots,bark,leaves and whole-plant of Clausena emarginata was historically used as a folk medicine for the treatment of coughs and headache,but there are only a few research about its chemical composition and its pharmacological activity has been reported until now.Carbazole alkaloids are widely presented in plants belonging to genus Clausena,them have a wide range of biological activities and have exhibited anti-tumor activities in a variety of cell models.For further development and utilization the medicinal plants resources,the purpose of this study is systemic research on the composition of alkaloids of Clausena emarginata guided by anti-tumor activity evaluation,clarify its efficacy material base and search compounds with significant antitumor activity.The dried stems and roots of Clausena emarginata were crushed and extracted by 90% Et OH,then the extractum has extracted by water and prtroleum ether.Then the extracts are isolated and purified by means of silica gel column chromatography,recrystallization,sephadex LH-20 and semi preparative HPLC separation method.Their structures were established on the basis of spectroscopic analyses such as IR、UV、EI-MS、NMR and so forth.Thirteen coumpounds were isolated and identified from the extract of Clausena emarginata,including: clausemargic A(1),(Z)-7-hydroxynuciferol(2),chlospicate E(3),ar-bisabol-9-en-7,11-diol(4),(+)-β-turmerone(5),3-methylcarbazole(6),murrayafoline A(7),3-methoxymethylcarbazole(8),1-methoxy-3-(methoxymethyl)-9H-carbazole(9),claulansine Q(10),claulansine R(11),claulansine S(12),claulansine T(13),3-formylcarbazole(14),murrayanine(15),3-formyl-6-methoxycarbazole(16),3-formyl-1,6-dimethoxycarbazole(17),clauraila A(18),claulansine J(19),murrastanine A(20),clausine I(21),girinimbine(22),murrayacine(23),clauraila E(24),siamenol(25),clausenaline D(26),claulansine E(27),chalepin(28),8-hydroxy-6-methoxy-3-pentylisocoumarin(29),ethyl orsellinate(30).Compounds 1-5 are sesquiterpenes,compounds 6-27 are carbazole alkaloids,compounds 28,29 are coumarins,and compound 30 is phenolic.Compound 1 is new compound,compounds 2-5,20,25,29-30 are isolated from the plants of genus Clausena for the first time.Compounds 8-13,17-19,22-24,26-28 are isolated from this plant for the first time.The anti-tumor activity of all carbazole alkaloids was evaluated by MTT method.The results showed that 12 carbazole alkaloids have significant growth inhibition activity to various cancer cell lines,the IC50 value was 0.28~15.18 μM.The inhibitory activity of compound 8 to five cancer cell lines are even stronger than positive control.This provides a basis for the study of anti-tumor activity of Clausena emarginata,and provides a new resource for searching for high-efficiency and low-toxicity anti-tumor drugs.