Studies On The Structures And Bioactivities Of Alkaloids From Rauvolfia Vomitoria And Two Aconitum Plants

Alkaloids are widely distributed in nature and mainly found in plants,animal,insect,microorganism and so on.Among them,researchers mainly focus on the alkaloids in plants in the past decades.Up to now,there are about 1900 kinds of alkaloids found in plants.These alkaloids can be classified into more than 60 types according to their carbon skeleton.Some of the main types are including organic amine,pyrrolidine,pyridine,isoquinoline,indoles,tropane,imidazoles,quinazolinones,purines,steroidal alkaloids,diterpenoid alkaloids,and so on.The complex structures and the significant physiological activities of alkaloids have attracted attentions of chemical and pharmacological scientists.In order to find novel and bioactive alkaloids from Chinese herb medicines,this study targeted the extraction,separation,structure identification and biological activitie evaluation of alkaloids from the selected medical plants Rauwolfia vomitoria（Apocynaceae）,Aconitumsungpanense（Ranunculaceae）,andAconitum sinomontanum（Ranunculaceae）.Seventy-three alkaloids were obtained by using various methods of separation,and their structures were identified by modern spectroscopy techniques and computer-assisted calculation,including eighteen new compounds.Firstly,twenty-seven alkaloids were isolated from the aerial part of Rauwolfia vomitoria,among them,rauvomine A and rauvomine B are two unusual normonoterpenoid indole alkaloids.Rauvomine B is a novel C₁₈ normonoterpenoid indole alkaloid with a substituted cyclopropane ring that forms an unusual 6/5/6/6/3/5 hexcyclic rearranged ring system.The compound also exhibited anti-inflammatory activity.Secondly,a total of tweenty diterpenoid alkaloids including eight new ones were isolated from Aconitum sungpanense.The tweenty diterpenoid alkaloids can be classfied as C₁₉-aconitine subtype and C₁₉-7,17-seco subtype.The eight new compounds were attributed to be one C₁₉-7,17-seco subtype and seven C₁₉-aconitine subtype alkaloids.Thirdly,twenty-seven diterpennoid alkaloids were isolated from Aconitum sinomontanum,which including three new C₁₉-lyconitine subtype,one new C₁₉-7,17-seco subtype,two new C₁₉-rearranged subtype,one new C₁₈-lappaconine subtype,and two new C₁₈-ranaconine subtype diterpenoid alkaloids.Finally,the isolated diterpenoid alkaloids were tested the antitumor and anti-inflammatory activities.The result showed that some of them showed anti-inflammatory activity,but no one showed antitumor activity for seven kinds of cancer cells selected.This paper also reviews the research progress of diterpenoid alkaloids from plants in the past ten years（from 2007 to 2017）,including their structures,biological activities,chemical name,CAS number,and belonging to family and species of the plants.This study would further enrich the natural alkaloids family and help researchers studying alkaloids constituents,bioactivities and structure-activity relationships of alkaloids from traditional medicinal plant resources in China.Also,this research would provide some theoretical support for screening new lead compounds an the chemotaxonomy.Furthermore,the research would provide some help for the development of traditional medicinal plant resources in China.