Screening Of Chemical Constituents And Activity Of Paulownia Catalpifolia Gong Tong Seeds

The dry seed of Paulownia catalpifolia Gong Tong is the subject of my research.As a traditional Chinese medicine,its root bark,flowers,leaves and fruits can be used as medicine.For a long time,Paulownia has been mainly used to treat diseases such as cough,phlegm,sore throat,bronchitis and gonorrhea.Modern medical research shows that Paulownia also has anti-tumor and anti-asthma effects.Objective The chemical constituents of P.catalpifolia Gong Tong seeds in the Paulownia plant of Scrophulariaceae family were studied systematically.To study the cholinesterase and xanthine oxidase inhibition activities of isolated monomeric compounds.The flavonoids and phenylethanoid glycosides compounds were studied in the relationship between xanthine oxidase inhibitory activity and structure.Methods Using Silica gel column chromatography,Sephadex LH-20 column chromatography,ODS column chromatography,preparative HPLC chromatography and recrystallization techniques to systematically studied the chemical constituents of n-butanol and ethyl acetate in the seeds of P.catalpifolia Gong Tong.The sructures of monomer compounds were identified by ESI-MS,UV,HRESIES,¹H-NMR,¹³C-NMR,IR,HMBC,HMQC spectral techniques as well as other chemical methods.The cholinesterase inhibitory activity of the isolated monomeric compounds was determined by ultraviolet spectrophotometry.The xanthine oxidase inhibitory activity of the isolated geranyl flavonoids and phenylethanoid glycosides was studied by HPLC.The IC₅₀ value was determined,enzyme kinetic constant and inhibition type of the more active compounds were determined.Results Twenty-seven compounds were isolated and purified from the seeds of Paulownia catalpifolia Gong Tong,and their structures were identified as:4',5,7-trihydroxy-3'-methoxy-6-[3,7-dihydroxy-3,7-dimethyl-2?E?-octyl]flavone?1?,3',5,7-trihydroxy-4'-methoxy-6-[7-hydroxy-3,7-dimethyl-2?E?-octenyl]flavanone?2?,4',5,5',7-tetrahydroxy-6-[6-hydroxy-3,7-dimethyl-2?E?-7-octadienyl]-3'-methoxyflavanone?3?,Isopaucatalinone B?4?,Prokinawan?5?,3,3',4',5,7-pentahydroxy-6-[7-hydroxy-3,7-dimethyl-2?E?-octenyl]flavanone?6?,6-geranyl-4',5,7-trihydroxy-3',5'-dimethoxyflavanone?7?,3,3',4',5,7-pentahydroxy-6-[6-hydroxy-3,7-dimethyl-2?E?,7-octadienyl]flavanone?8?,Tomentin E?9?,Tomentin D?10?,?2S?-2-?4-hydroxy-3-methoxyphenyl?-5-hydroxy-8-?4-hydroxy-4-methylpentyl?-8-methyl-2,3,7,8-tetrahydropyrano[3,2-g]chromen-4?6H?-one?11?,?2S?-2-?4-hydroxyphenyl?-5-hydroxy-8-?4-hydroxy-4-methylpentyl?-8-methyl-2,3,7,8-tetrahydropyrano[3,2-g]chromen-4?6H?-one?12?,6-geranyl-3,4',5,7-tetrahydroxy-3'-methoxyflavanone?13?,Guaiacylglycerol-?-ferulic acid ether?14?,Erythro-?7S,8R?-guaiacylglycerol-?-coniferyl aldehyde ether?15?,Isoacteoside?16?,Acteoside?17?,Ilicifolioside A and Isoilicifolioside A mixture?18?,Plantalloside?19?,Orobsnchosid?20?,Tomentoside?21?,Campneoside I?22?,Darendoside B?23?,Apigenin?24?,Luteolin?25?,Cistanoside F?26?,Linarin?27??The anti-cholinesterase activity of twenty-seven compounds isolated from the seeds of P.catalpifolia Gong Tong was studied.The activity screening results showed that compounds 5,6,8 and 16 had higher double cholinesterase inhibitory activity than other compounds.Among them,compound 16 has a smaller IC₅₀ value and has a good inhibitory effect on cholinesterase.The preliminary analysis of the activity of xanthine oxidase was carried out by HPLC method on 8 phenylethanoid glycosides and 12 geranyl flavonoids.The results showed that compounds 5,16,19,22 had better inhibition rate.These four compounds were further explored,including IC₅₀ values and determination of enzyme kinetic activity.Conclusions Twenty-seven compounds were isolated and purified from the seeds of P.catalpifolia,including two new compounds:1,2.Seven compounds:6,8,16,17,18,22,25were first found in P.catalpifolia;Eight compounds:5,14,15,19,20,21,23,26 were first discovered in Paulownia.The screening results of cholinesterase activity indicated that compounds 5,6,8 and 16 had higher dual cholinesterase inhibitory activity,but their IC₅₀was higher than positive control-donepezil.Among them,compound 16 has a smaller IC₅₀value and a higher inhibitory effect on cholinesterase.The inhibitory activity of xanthine oxidase was determined by HPLC.The preliminary results showed that the compounds 5,16,19,22 had a good inhibition rate and a certain dose-effect relationship.First,measuring the reaction rate and then Lineweaver–Burk plots were constructed for the inhibition of xanthine oxidase,and expressed as 1/velocity?1/V?versus 1/substrate?1/[S]?,the results showed that compounds 5,16 and 19 are all mixed inhibition.