Chemical Constituents From The Petroleum Ether Fraction Of Lomatogonium Rotatum And Their Proliferation Inhibition On Tumor Cell

Lomatogonium rotatum（L.）Fries ex Nym.is belonging to the family Gentianaceae,it is widely distributed in Tibet,Xinjiang,Inner Mongolia,etc.It has the effects of clearing away heat,invigorating the stomach and healing wounds,and is used for the treatment of diseases such as warm fever,typhoid fever,heat stroke,headache,liver and gallbladder fever.It has pharmacological effects such as liver protection,anti-inflammatory,anti-oxidation,anti-tumor,etc.In order to make better use of natural medicine resources and give full play to its medicinal value,this study evaluated chemical composition and their anti-tumor activity from L.rotatum.The whole plants of air-dried L.rotatum were extracted with 75%Et OH,and partitioned with petroleum ether,Et OAc and n-Bu OH,successively.The petroleum ether part was separated and purified by various chromatographic techniques to obtain18compounds,includingninexanthonescompounds,1,8-dihydroxy-3,5-dimethoxyxanthone（1）,1-hydroxy-3,5-dimethoxyxanthone（2）,1,8-dihydroxy-3,7-dimethoxyxanthone（3）,1-hydroxy-3,7,8-trimethoxyxanthone（4）,1,2,8-trihydroxy-5,6-dimethoxyxanthone（5）,1-hydroxyl-3,5,8-trimethoxyxanthone（6）,1,8-dihydroxy-3,4,5-trimethoxyxanthone（7）,1,7-dihydroxy-2,8-dimethoxy--xanthone（8）,1,3,5R,8S-tetrahydroxy-5,6,7,8-tetrahydroxanthone（9）,together with five triterpenoids,oleanolic acid（10）,2α,3β-dihydroxyurs-12-en-28-oic acid（11）,2α,3α,23-trihydroxyurs-12-en-28-oic acid（12）,2α,3β,19α-trihydroxyurs-12-en-28-oic acid（13）and 2α,3β,19α,23-tetrahydroxyurs-12-en-28-oic acid（14）,three lignans,（+）-syringaresinol（15）,（+）-pinoresinol（16）,dehydrodiconiferyl alcohol（17）and one flavonoid,luteolin（18）.Among them,compounds 2,3 were isolated from this plant for the first time,5,11,13,15 and 16 were firstly identified from the genus Lomatogonium,12,14 and 17 were the first to be reported in the family Gentianaceae.Anti-tumor activity of compounds 1-18 against cancer cell lines of He La、A-549 and SK-Hep1 was evaluated by MTT assay,10 and 12 exhibited strong inhibitory activities against these three kinds of tumor cells.The IC₅₀ values of compound 10against the three tumor cells were 14.82±1.53,25.80±3.91 and 8.11±0.78μM,respectively.And compounds 12 showed IC₅₀ values of 21.34±1.62,29.26±2.35and 16.24±2.09μM.