Studies On The Chemical Constituents Of Onosma Paniculatum

This thesis consisted of three chapters.The first chapter reviewed the advances in the chemical constituents of the Boraginaceae and shikonin.The second chapter discussed the phytochemical studies on Onosma paniculatum.And in the last chapter,conclusion of this dissertation was made.Traditional Chinese Medicine of the "Zicao" has two species in The Pharmacopoeia of China(2010 Edition),namely,dried root of the Arnebia euchroma and Arnebia guttata.In addition,the dried root of the Onosma paniculatum is also used as local medicine.It,well known traditional medicinal plants,has long been used for the treatment of various diseases.Modern pharmacology shows that shikonin and its derivatives have the antiviral,antibacterial,liver-protection and anti-inflammatory activities.However,the effective component of "Zicao" in antiviral has been no consensus.Generally,the naphthoquinone compounds are considered to take effect,namely the constituents of shikonin and its derivatives.They play a role in the inhibition of the hepatitis A virus(HAV)and hepatitis B virus(HBV).At the same time,they also have good curative effect on endoretention of damp heat,heat toxin stagnation,abnormal of liver-function and elevated to the ALT caused by HBV.We have found that shikonin exhibited potent anti-HCV activity with a selective index of 43.56,while the ribavirin with a selective index of 7.89.As a continuation of our search for more new secondary metabolites with potential bioactivities,we systematically investigated the O.paniculatum.Twelve known compounds were isolated from the 70%acetone exctact of O.paniculatum,and their structures were identified as β-acetoxyisovalerylshikonin(1),deoxyshikonin(2),β,β’-dimethylacrylshikonin(3),isobutyrylshikonin(4),propionylshikonin(5a),acetylshikonin(5b),5α,8α-epidioxyergosta-6,22-diene-3β-ol(6),3β-O-acetyloleanolic acid(7),oleanolic acid(8),cholest-5-en-3β-ol(9),β-sitosterol(10),and etracosanoic acid(11).Compounds 1-5 are shikonin derivatives.Compounds 6,7 and 9 are isolated from this genus for the first time.