Chemical Constituents Of Sophora Tonkinensis And Fragmentation Patterns Of The Flavonoids In ESI Mass Spectrometry

Sophora tonkinensis,a species of the Sophora genus in Leguminosae family,is an important traditional Chinese herbal plant,named Shan-Dou-Gen in Chinese.It is mainly distributed in Guangxi,Guizhou,Yunnan,Guangdong,and Jiangxi Provinces. Its roots and rhizomes are used for the treatment of acute pharyngolaryngeal infections and sore throats.Sophora flavescens,named Ku-Shen in Chinese,is also a Chinese herbal plant of the same Sophora genus.Its roots and rhizomes,which have different clinical applications from Shan-Dou-Gen,are mostly used to treat skin diseases and the gynaecological diseases.In order to provide scientific evidence for further understanding the relationships between the chemical constituents and the unique medicinal properties claimed for Shan-Dou-Gen and Ku-Shen,and also to establish the foundation for the further research and development of the Sophora plants,the chemical constituents of S.tonkinensis were systemically investigated.From the 95%ethanol extract of the roots of S.tonkinensis,40 compounds, including seven alkaloids,29 flavonoids,one triterpenoid,and three steroids,were isolated using various chromatographic methods.On the basis of MS,IR,NMR,CD, X-Ray,and physico-chemical character,the structures of the compounds were identified as following:（+）-matrine（A-1）,（+）-oxymatrine（A-2）,（+）-sophoranol（A-3）, （-）-5α-hydroxysophocarpine（A-4）,（-）-cytisine（A-5）,tonkinensine A（A-6）, tonkinensine B（A-7）,8-C-prenylkaempferol（F-1）,tonkinensisol（F-2）,lupinifolin（F-3）, tonkinochromane L（F-4）,glabrol（F-5）,kushenol E（F-6）,2’,4’,7-trihydroxy-6,8-bis（3-methyl-2-butenyl）flavanone（F-7）,2-（2’,4’-dihydroxy-phenyl）-8,8-dimethyl-10-（3-methyl-2-butenyl）-8H-pyrano[2,3-d]chroman-4-one（F-8）,6-[3-（2’,4’-dihydroxy phenyl）acryloyl]-7-hydroxy-2,2-dimethyl-8-（3-methyl-2-butenyl）-2H-benzopyran（F-9）, sophoranone（F-10）,sophoranochromene（F-11）,2-[{3’-hydroxy-2’,2’-dimethyl-8’- （3-methyl-2-butenyl）}chroman-6’-yl]-7-hydroxy-8-（3-methyl-2-butenyl）chroman-4-one （F-12）,tonkinochalcone（F-13）,2-[{2’-（1-hydroxy-1-methylethyl）-7’-（3-methyl-2-butenyl）-2’,3’-dihydrobenzofuran}-5’-yl]-7-hydroxy-8-（3-methyl-2-butenyl）-chroman-4-one（F-14）,tonkinochromane M/N（F-15/16）,tonkinochromane O/P（F-17/18）, tonkinochromane F（F-19）,tonkinochromane G（F-20）,tonkinochromane I（F-21）, tonkinochromane H（F-22）,tonkinochromane K（F-23）,tonkinochromane J（F-24）, formonocetin（F-25）,genistein（F-26）,7,2’-dihydroxy-4’-methoxy-isoflavanol（F-27）, （-）-maackiain（F-28）,（-）-trifolirhizin（F-29）,lupeol（E-1）,stigmasterol（E-2）,β-sitosterol（E-3）,andβ-sitosterol-3-O-β-D-glucoside（E-4）.Among them,compounds A-6 and A-7 were the novel alkaloids with a new skeleton. Compounds F-4 and F-15～24 were new isoprenylated flavonoids.Compound F-27 was isolated from the genus of Sophora for the first time,and compounds F-1,F-3, and F-5 were isolated from S.tonkinensis for the first time.In order to lay a solid foundation for the quality control as well as in vitro and in vivo metabolism of S.tonkinensis and other traditional Chinese herbal medicines,the fragmentation patterns of the isoprenylated flavonoids were investigated using the ESI mass spectrometry.The results revealed that the quasi molecular ions were clearly displayed in the negative ion mode.And the compounds can be distinguished from each other by the characteristic ^1,3A^- ion and ^1,3B^- ion according to the Retro Diels Alder Cleavage and the characteristic fragments originated from the degradation of different isoprenyl groups in the MSⁿ spectra.