| Chinese dragon’s blood(CDB),which belongs to the genus Dracaena(Liliacaeca family),is the red resin of Dracaena cochinchinensis(Lour.)S.C.Chen,which is widely distributed in Guangxi and Yunnan provinces of China and Southeast Asian countries.It has been used to promote blood circulation and remove blood stasis for centeries.Longxuetongluo Capsule(LTC),which contains the total phenolic extract of CDB,was approved for the treatment of ischemic stroke by China Food and Drug Administration in June 2013.However,the bioactive constituents of this drug have not yet been fully characterized because of the difficulties associated with the separation of these compounds,.especially for flavonoid oligomers.Previously,57 phenolic compounds have been obtained’from the total phenolic extract of CDB by our group.In order to further clarify the bioactive components of LTC,an LCMS-IT-TOF-guided separation procedure was performed on the phenolic constituents of LTC.In addition,the inhibitory activities of the isolated compounds on nitric oxide(NO)production in lipopolysaccharides(LPS)-stimulated BV-2 microglial cells as well as their protective activities on oxygen and glucose deprivation/reperfusion(OGD/R)-trigggered injury in PC 12 cells were evaluated in vitro The results are listed as below.1.The research progress of chemical constituents and bioactivities of Dracaena cochinchinensis have been reviewed.The main chemical constituents of the plants from this genus are dihydrochalcone,chalcone,flavane,homoisoflavane,homoisoflavone,flavanone,flavone,flavonoid oligomers,lignans,steroidal saponins,among others.The crude extracts and pure compounds from D.cochinchinensis plants have been found to exhibit a wide array of biological activities including cerebral protection,myocardial protection,anti-atherosclerosis,improving hemorheological parameters,antithrombotic,anti-platelet aggregation,anti-inflammatory,anti-diabetic,anti-microbial,antioxidant,and wound healing.2.A total of 19 compounds were isolated and purified by various column chromatogramphic techniques(semi-preparative HPLC,Sephadex LH-20 gel,silica gel,and ODS),and their structures were elucidated on the basis of their physiochemical properties,spectroscopic data(UV,IR,MS,1H NMR,13C NMR,2D NMR)as well as their X-ray diffraction and electronic circular dichroism(ECD)data.These compounds include cochinchinenin N(1),cochinchinenin O(2),cochinchinenin P(3),(-)-cochinchinenin I(4),(+)-cochinchinenin I(5),(7R,12bR)-7,10-dihydroxy-4,11-dimethoxydracaenone(6),(7S,12bS’)-11-hydroxy-1,10-dimethoxydracaenone(7),(7S,12bS’)-10,11-dihydroxy-1-methoxydracaenone(8),(3S)-3,7,4’-trihydroxy-5-methoxyhomoisoflavanonol(9),(3R)-7,4’-dihydroxy-6-methoxyhomoisoflavane(10),dracophone(11),10-hydroxy-11-methoxydracaenone(12),7,4’-dihydroxy-5-methoxyhomoisoflavanone(13),5,4’-dihydroxy-7-methoxyhomoisoflavone(14),secoisolariciresinol(15),syringaresinol(16),ciwujiatone(17),5,7-dihydroxy-4’-methoxyflavone(18),and androstan-1,4-dien-3,16-dione(19).Compounds 1-10 are new compounds.Compound 19 was firstly isolated from the family Liliaceae.Compounds 13,14 and 18 were obtained from the genus Dracaena for the first time.In addition,the absolute configurations of seven flavonoid dimers,which were obtained from the total phenolic extract of CDB in our previous phytochemical investigation,were assiagned by comparison of their experimental and calculated ECD data.3.The NO inhibitory effects of the isolated compounds on LPS-stimulated BV-2 microglial cells were evaluated in vitro.Flavonoid oligomers,and chalcone showed moderate inhibition of NO production in LPS-stimulated BV-2 microglial cells.The protective effects of the isolated compounds on oxygen and glucose deprivation/reperfusion(OGD/R)-trigggered injury in PC 12 cells were evaluated in vitro.Flavonoid oligomers significantly protected PC 12 cells against OGD/R-induced injury. |
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