Studies On The Chemical Constituents And Bioactivities Of Aconitum Barbatum Var. Puberulum

Aconitum barbatum var.Puberulum,an herbal drug,is a flowering plant belonging to Aconitum genus.It is 50-90 cm high and its roots are near-vertical and cylindrical,rough about 8 mm.It is located in the eastern part of Xinjiang,Shanxi, Hebei and Inner Mongolia.They mainly grow in hillside,hollow,roadside,dene and tussock.The whole plant is toxic and the toxicity becomes severer after the stems and leaves wither.In order to explore much more pharmacological constituents of Aconitum barbatum var.Puberulum,The chemical constituents of EtOAc and n-butanol fractions of EtOH extraction were respectively isolated by means of silica gel column chromatography(CC),preparative thin layer column(PTLC)and recrystallization etc, and 41 compounds were obtained;the structures of 38 compounds were elucidated on the basis of spectroscopic methods:IR,EI-MS,HR-ESI-MS,HR-EI-MS,1D NMR (¹H NMR,¹³CNMR,DEPT,NOE,TOCSY),2D NMR(¹H-¹H COSY,HMQC,HMBC,NOESY),along with comparison with authentic samples or the data from literature,or proper chemical transformations.They were identified as norditerpenoid alkaloids,diterpenoid alkaloids,flavonoids,and steroides etc,six of which were new compounds.Screening the bioactive compounds in the species,cylinder-plate assay was employed to evaluate the antimicrobial activities of the alkaloids isolated from Aconitum barbatum var.Puberulum and a certain potency of antibiotics was found for all the alkaloids against Gram-positive(Staphylococcus aureus,Bacillus subtilis and Staphylococcus epidermidis)and Gram-negative(Escherichia coli,and Pseudomonas aeruginosa)microorganisms.Remarkably,compounds 5,8,11,18,22,23 showed strong antibacterial activity against S.aureus;compounds 2,10,11,17,20,22,23,24 exhibited antimicrobial activity against S.epidermidis;compounds 3,14,17,23,24 inhibited B.subtilis eminently;compounds 4,8,9,17,22,24,27 prohibited E.coli effectively;compounds 1,2,3,11,27 presented prominent inhibitory effect on P. aeruginosa.Meanwhile,antioxidant studies against DPPH were carried out for some compounds isolated from Aconitum barbatum var.Puberulum.The results indicated that compound 8,9,11,12,13,14,18 showed antioxidant activity and the other alkaloids presented no capacity against DPPH.In the end of the thesis,one review was made on the systemic summarization for the chemical constituents of the genus Aconitum reported since 2000.The results of the investigation were expected to enrich the database of natural products,to afford the scientific basis of pharmacology,chemotaxonomy and screening of new medicines,and to help the utilization of the Chinese natural resources as well as the research of Chinese herbal modernization.