Study On Chemical Constituents Of Dai Medicine Fissistigma Polyanthum

Fissistigma polyanthum is a climbing shrub of the Fissistigma,also known as Mai Han by the Dai nationality.It is a medicinal plant commonly used in traditional therapies and herbal treatments for rheumatoid arthritis and bone joint related diseases.It grows in large quantities in China,India,Myanmar,and Vietnam,but there are limited reports on its chemical composition and biological activity in literature.The anti-Alzheimer’s disease（AD）potential of this plant has not yet been reported.In this thesis,the components of Fissistigma polyanthum were isolated and identified,and cholinesterase inhibition and amyloid protein(Aβ_1-42)aggregation inhibition and antioxidant activity determination.In this thesis,the chemical constituents of the roots of Fissistigma polyanthum from Xishuangbanna,Yunnan Province were extracted,separated and purified by silica gel chromatography column,high performance liquid chromatography,Sephadex LH-20 gel column,Toyopeal HW-40 gel column and other means.The structure of the compounds was analyzed by nuclear magnetic resonance hydrogen carbon spectroscopy,mass spectrometry,two-dimensional spectrum,circular dichroism and other methods.A total of 19 compounds were isolated and identified from Fissistigma polyanthum.They are Fissanthone（1）、Fissanthine C（2）、Fissanthine D（3）、Fissanthine E（4）、Fissanthine F（5）、（-）-lsolaureline（6）、Oxoxylopine（7）、Duguevanine（8）、Fissilandione（9）、Oldhamactam（10）、Aristololactam Al Ila（11）、Piperolactam A（12）、Aristololactam B II（13）、（-）-Klkernanine（14）、Fissisaine（15）、（-）-Thaipetaline（16）、5,7,8-trimethoxy-dihydroflavone（17）、2’-hydroxy-3’,4’,6’- trimethoxydihydrochalcone（18）、Annonbraine（19）.Compounds（1）,（2）,（3）,（4）and（5）are new compounds.Compounds（12）and（18）were isolated from the Fissistigma for the first time,and compounds（6）,（7）,（8）,（9）,（10）,（11）,（13）,（14）,（15）,（16）,（17）,（19）were isolated from the Fissistigma polyanthum for the first time.Compound（7）showed high dual-target aggregation inhibition by comparing the cholinesterase activity data and the inhibitory activity data of Aβ_1-42.Compounds（3）,（6）,（7）,（12）,（13）and（16）had certain acetylcholinesterase inhibitory activity.Compounds（6）and（19）had certain inhibitory activity of butyryl cholinesterase,and the IC₅₀of compound（19）was 13.67±1.72μM,showing good inhibitory activity of butyryl cholinesterase.Compounds（2）,（4）,（5）,（8）and（11）had certain antioxidant activity.The IC₅₀value of compound（11）was 9.29±0.83μM,which was lower than that of Trolox,showing good free radical scavenging ability.Compounds（1）,（2）,（7）and（11）showed good aggregation inhibition activity of Aβ_1-42.The IC₅₀of compound（1）was 26.56±0.7μM,which showed good aggregation inhibition activity of Aβ_1-42.Alzheimer’s disease（AD）is a neurodegenerative disease.At present,pharmacological research focuses on acetylcholinesterase（ACh E）and butyrylcholinesterase（BCh E）inhibitors,but due to amyloid protein(Aβ_1-42)the process of fiber formation directly leads to the occurrence and development of AD,which is one of the pathological bases.Therefore,inhibiting Aβ_1-42Aggregation can provide a feasible treatment strategy for slowing down the progression of this disease.At present,the research has both cholinesterase（Ch Es）and Aβ_1-42new drugs with aggregation inhibition will have important research value for the development of anti-AD drugs.