Studies On The Alkaloidal Constituents Of Kopsia Officinalis

Kopsia officinalis is rich in monoterpene indole alkaloids with a wide range of biological activity.A series of monoterpenoid indole alkaloids with complex skeletons and multitudinous types have been identified from the plant in which new ingredients are constantly being discovered.In order to further find new indole alkaloids possessed of bioactivity,the alkaloids from Kopsia officinalis were isolated,purified,and identified.Totally,31 alkaloids were isolated and identified,in which four were new compounds.After the stems and leaves of Kopsia officinalis were soaked and extracted with acetone and methanol successively,various chromatographic methods including Sephadex LH-20 gel column chromatography and normal and reverse silica gel column chromatography were used to separate and purify the alkaloidal composition of the acetone extract to obtain 23 alkaloids.The structure of these compounds was identified based on spectroscopy（1D-NMR,2D-NMR,MS,etc.）and physical and chemical properties.These structures are 12-methoxykopsinaline N（4）-oxide（1）,kopsinoline（2）,11,12-methyle-nedioxykopsinaline N（4）-oxide（3）,5-oxokopsinic acid（4）,kopsinilam（5）,5,22-dioxokopsane（6）,methyl N₁-decarbomethoxychanofruticosinate（7）,11?-hydroxyerythratinone（8）,erythratine N-oxide（9）,11-nor-10-oxoerythratine（10）,erythratinone（11）,（+）-10,11-dioxoerythratine（12）,11?-hydroxyerythratine（13）,erythratine（14）,11-hydroxyerythratidine（15）,epi-erythratidine（16）,erysotine（17）,cristanine E（18）,erythrinine（19）,reticuline（20）,（+）-laudanidine（21）,dibenzazonine（22）and（s）-coreximine（23）respectively.Four of them are new alkaloids.Alkaloid 1is a new aspidospermine alkaloid,and alkaloids 8-10 are new Erythrina alkaloids.Alkaloids 11-23 were originally isolated from the genus Kopsia.Eight alkaloids were isolated and identified from the methanol extracts of branches and leaves of Kopsia officinalis.Their structures were identified based on spectroscopy（1D-NMR,2D-NMR and MS）and physicochemical properties.These compounds are fruticosamine（24）,fruticosine（25）,kopsinine（26）,（-）-N-methoxycarbonyl-11,12-methylenedioxy kopsinaline（27）,kopsinidine A（28）,venalstonidine（29）,（-）-tetrahydroalstonine（30）,strictanol（31）.Among them,alkaloid31 was isolated for the first time from the genus Kopsia,and alkaloid 24 was originally isolated from Kopsia officinalis.Screening for the inhibitory effects of these compounds on melanoma is still underway.Finally,alkaloids and their biological activities of Kopsia officinalis were reviewed.