Studies On Chemical Constituents From Dalbergia Pinnata And Their Anti-Inflammatory Activities

Dalbergia pinnata(Lour.)Prain is a kind of legume tree belonging to the genus Dalbergia,also known as ’Xie Ye Tan’,’Luo Wang Zi Ye Huang Tan’ in China.It is mainly distributed in Myanmar,Philippines,Malaysia,Indonesia and southern region of China.The whole plant has the effect of reducing swelling and pain,and has been used as folk medicine for the treatment of rheumatism,bruise,anti sprain and so on.In ancient times,Dalbergia pinnata was used as incense by high ranking officials and aristocracy,in Ben Cao Gang Mu,it was recorded that the Dalbergia pinnata could be used to treat bruises and knife wounds.The inhabitants in Hainan,Yunnan and other parts of China regard Dalbergia pinnata as a precious commodity,which was often used for brewing wine or applied unilaterlly,for the treatment of injuries such as bruises,burns and scalds,snake and insect bites,as well as auxiliary treatment of acute and chronic gastroenteritis,rheumatoid arthritis,respiratory diseases,cardiovascular diseases,diabetes.In order to further clarify the chemical composition of Dalbergia pinnata and to develop and enrich the medicinal resources of it,the chemical composition of Dalbergia pinnata was investigated in this study,a more systematic study was carried out and the anti-inflammatory activity of some of the isolated compounds was determined.A total of 30 compounds were purified from the methanolic extract of the dry heartwood of Dalbergia pinnata using silica gel column chromatography,Sephadex LH-20 column chromatography,ODS column chromatography and semi-preparative high performance liquid chromatography,and the structures were identified by infrared spectroscopy(IR),nuclear magnetic resonance spectroscopy(NMR),high resolution mass spectrometry(HR-MS)and circular dichroism chromatography(CD)as follows:dalberatin F(1),dalberatin G(2),dalberatin H(3),isomucronustylene(4),dalberatin C(5),retusin-8-methylether(6),formononetin(7),khrinone A(8),butin(9),7-hydroxy6-methoxy-2-phenylchroman-4-one(10),liquiritigenin(11),3,4-dihydroxy-9Methylenedioxypterocarpan(12),melilotocarpan A(13),medicarpin(14),lespedezol D1(15),4-hydroxy-3-methoxy-8,9-methylenedioxypterocarpan(16),4methoxymaackiain(17),3,4-dihydroxy-8,9-methylenedioxypterocarpan(18),4methoxymedicarpin(19),maackiain(20),elemicin(21),8-O-methyl-fusarubin(22),mimosifoliol(23),candenatenin H(24),duartin(25),candenatenin D(26),isoliquiritigenin(27),3,4,5-trimethoxycinnamyl alcohol(28),2,4-dihydroxy-5methoxy-benzo-phenone(29),3’-O-methylviolanone(30).The isolated compounds were all obtained for the first time from the plant,with compounds 1-3 being new compounds.Compounds 1-20 were evaluated the cytotoxic effect against macrophage RAW264.7 cells via MTT assay.The results showed that 2 compounds(1,16)showed significant toxic effects on RAW264.7 even at low concentrations.Anti-inflammation of the remaining 18 compounds using LPS-stimulated RAW264.7 inflammatory model in vitro activity screen,11 of these compounds were shown to effectively inhibit NO metabolism in macrophage RAW264.7,each IC50 of the compounds ranging from 1.79μM to 29.50 μM,respectively,the IC50 value of indomethacin was 29.66 μM,indicating that each compound had better anti-inflammatory activity.The experimental results showed that some cinnamylphenols and pterostilbene compounds isolated from Dalbergia pinnata had good anti-inflammatory activities,but the compounds were not effective.There are also some compounds with strong cytotoxicity,but their constitutive relationships are still unclear and require further study.