Studies On The Chemical Constituents And Anti-oxidation,Anti-inflammatory Activity Of Paulownia Catalpifolia Gong Tong Fruit Peel

Paulownia catalpifolia Gong Tong,a plant of Paulownia of the family Scrophulariaceae?Scrophulariaceae?.The subject studied the dry fruit peel of Paulownia catalpifolia Gong Tong.There are 8 species of Paulownia in the Scrophulariaceae family,which are widely distributed throughout China.It is a traditional Chinese medicine in China.Its flowers,leaves,fruits and root bark can be used as medicine.For a long time,paulownia has been used as a traditional medicine to treat various diseases such as cough,sputum,sore throat,acne,gonorrhea,and bronchitis.Modern medical research has shown that paulownia has antibacterial,anti-inflammatory and anti-tumor effects.Objective To systematically study the chemical constituents of the peel of Paulownia catalpifolia Gong Tong in the Paulownia plant of the family Scrophulariaceae.To study the antioxidant and anti-inflammatory activities of the extract and the isolated monomer compounds of Paulownia catalpifolia Gong Tong,Including the effect of protect human umbilical vein endothelial cells?HUVEC?from H₂O₂ injury,and the relationship between the structure of flavonoids and the resistance to H₂O₂ injury.Meanwhile,the effects of ethyl acetate extract and n-butanol extract from Paulownia catalpifolia Gong Tong fruit peel on ovalbumin-induced allergic airway inflammation in BALB/c mice were investigated.Methods The chemical constituents of the dichloromethane extract from Paulownia catalpifolia Gong Tong fruit peel were systematically studied by means of silica gel column chromatography,ODS column chromatography,Sephadex LH-20 column chromatography,TLC preparation,preparative HPLC chromatography and recrystallization techniques.The structures were identified on the basis of their chemical and physical properties as well as the spectra data of ESI-MS,HRESIMS,¹H-NMR,¹³C-NMR,IR,HMBC,HSQC,CD,¹H-¹H COSY,NOESY and other spectroscopic techniques.Study on the protective effects of compounds on H₂O₂ injured human umbilical vein endothelial cells by MTT assay.Explore the effects of compounds on apoptosis of H₂O₂ injured human umbilical vein endothelial cells by Annexin V-FITC/PI double staining method.Airway inflammation in BALB/c mice induced by ovalbumin sensitization and local atomization,and then oral administration of ethyl acetate extract,n-butanol extract from Paulownia catalpifolia Gong Tong fruit peel and Diplacone was performed to investigate their effects on airway inflammation in BALB/c mice.Results Thirty-three compounds were obtained from the 70% ethanol extract of Paulownia catalpifolia Gong Tong fruit peel and identified as :6-geranyl-4',5',5,7-tetrahydroxy-3'-methoxyflavone?I?,4',5',5,7-tetrahydroxy-3'-methoxy-6-[7-hydroxyl-3,7-dimethyl-2?E?-octenyl] flavones?II?,4',5,7-trihydroxy-3',5'-dimethoxy-6-[7-hydroxy-3,7-dimethyl-2?E?-octenyl]flavonol?III?,4',5,7-trihydroxy-3'-methoxy-6-[7-hydroxy-3,7-dimethyl-2?E?-octenyl] flavonol?IV?,4',5,7-trihydroxy-3',5'-dimethoxy-6-[7-hydroxy-3,7-dimethyl-2?E?-octenyl] flavanone?V?,?2R,3R?-3',5,7-trihydroxy-4'-methoxy-6-[7-hydroxyl-3,7-dimethyl-2?E?-octenyl]flavanonol?VI?,?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?VII?,?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?VIII?,2-?3,4-dihydroxy-5-methoxyphenyl?-5,7-dihydroxy-6-??3-hydroxy-2,2-dimethyl-6-methylenecyclohe xyl?methyl?chroman-4-one?IX?,5,7-dihydroxy-2-?4-hydroxy-3,5-dimethoxyphenyl?-6-??E?-6-hydroxy-3,7-dimethylocta-2,7-dien-1-yl?chroman-4-one?X?,5,7,3',4'-tetrahydroxy-8-geranyl flavanone?XI?,?2S?-5,7-dihydroxy-2-?3-hydroxy-4,5-dimethoxyphenyl?-6-?2-?2,6,6-trimethyletrahydro-2H-pyran-2-yl?ethyl?chroman-4-one?XII?,Diplacone?XIII?,Diplacol?XIV?,3'-O-Methyldiplacol?XV?,3'-O-Methyldiplacol-6-geranyl-4?,5,7-trihydroxy-3?,5?-dimethoxyflavanone?XVI?,Isopaucatalinone B?XVII?,4?,5,7-trihydroxy-6-[7-hydroxy-3,7-dimethyl-2-?E?-octene]flavanone?XVIII?,4?,5,5?,7-tetrahydroxy-6-[6-hydroxy-3,7-dimethyl-2?E?-7-octadienyl]-3?-methoxyflavanone?XIX?,Tomentin D?XX?,Tomentin B?XXI?,Tomentin E?XXII?,4',5',5,7-tetrahydroxy-3'-methoxy-8-[7-hydroxyl-3,7-dimethyl-2?E?-octenyl] flavanone?XXIII?,Apigenin?XXIV?,Oleanic acid?XXV?,2?,3?,19?-trihydroxyurs-12-en-28-oic acid?XXVI?,2?,3?,23-trihydroxyolean-12-en-28-oic acid?XXVII?,Myrianthic acid?XXVIII?,Balanophonin?XXIX?,8-hydroxy-9-methoxy-1,2,3,5,6,10b-hexahydropyrrolo [2,1-a]isoquinolin-3-one?XXX?,8,9-dimethoxy-1,2,3,5,6,10b-hexahydropyrrolo [2,1-a]isoquinolin-3-one?XXXI?,Stigmasterol?XXXII?,?-sitosterol?XXXIII?.The activity test of anti-H₂O₂ injury was performed on the 16 chemical constituents isolated from the extracts of Paulownia catalpifolia Gong Tong fruit peel.The results showed that IV,V,VIII,IX,XIX,XX,and XXIII can inhibit human umbilical vein endothelial cell damage caused by H₂O₂.In particular,compounds V,XIX,XX and XXIII can significantly resist H₂O₂ injury and increase the survival rate of HUVEC.We further studied the effects of compound V,XIX,XX,and XXIII on apoptosis of HUVEC damaged by H₂O₂ and found that all four compounds showed different degrees of inhibition of HUVEC apoptosis.In particular,compounds XX,XXIII and XIX significantly inhibited HUVEC apoptosis induced by H₂O₂,which were significantly different from that of the control group.The ethyl acetate extract and n-butanol extract of Paulownia chinensis fruit peel can decrease inflammatory cell infiltration of bronchioles,perivascular,alveolar cavity and interstitial lung tissue,reduce mucus secretion and airway inflammation.They can also reduce the concentrations of inflammatory cytokines IL-4,IL-5,and IL-13 in BALF of asthmatic mice,and reduce the number of leukocytes and inflammatory cells in peripheral blood.The effect is best with high doses,and the effect with low doses is not obvious.Conclusions Thirty-three compounds were isolated from dichloromethane extract from Paulownia catalpifolia Gong Tong fruit peel.Compounds I-XII are novel compounds.Compounds XXX and XXXI are new compounds in nature.Compound XXIX was first discovered in Paulownia.Compounds XIII,XIV,XV,XVI,XVII,XVIII,XIX,XX,XXI,XXII,XXIII,XXIV,XXV,XXVI,XXVII,XXVIII were first found in Paulownia catalpifolia Gong Tong.Among the 15 compounds tested,8 geranyl substituted flavonoids flavonoids can inhibit H₂O₂-induced HUVEC injury to varying degrees.In particular,compounds IX,XIX,and XXIII significantly increased the survival rate of HUVEC.The ethyl acetate extract and n-butanol extract of Paulownia catalpifolia Gong Tong fruit peel alleviated the infiltration of bronchiolar and perivascular inflammatory cells in asthmatic mice as well as reduced airway epithelial mucus secretion and improved airway inflammation in asthmatic mice.Inhibiting the secretion of inflammatory cytokines IL-4,IL-5,and IL-13,thereby promoting the differentiation of Th0 into Th1,inhibiting the differentiation of Th0 into Th2,and reversing the imbalance of Th1/Th2 may be one of the mechanisms for the prevention and treatment of asthma.