Study On Chemical Constituents And Biological Activities From Ethyl Acetate Extract Of Benzoin

As a fragrant natural resin,benzoin is a viscous substance secreted by genus Styrax tonkinensis of the benzoin plant or the bark of the benzoin tree after it is injured.The resin of the former is called Thai benzoin and the latter is called Sumatran benzoin,which is mainly used as drug in China.Dating back to the world’s earliest pharmacopoeia "Tang Ben Cao" compiled in 659 A.D.,benzoin has been used in Chinese medicine for thousands of years,it has the function of refreshing,promoting blood circulation and relieving pain,and can be used to treat stroke phlegm syncope,postpartum fainting and sudden syncope and so on.Modern pharmacological studies have shown that benzoin extract had significant anti-inflammatory and antipyretic activities,promoting blood-brain barrier,anti-atherosclerosis and anti-tumor activities.In the previous work,guided by modern pharmacological studies,we investigated the major components of benzoin,isolated chemical components represented by oleanolane triterpenes from benzoin,and tested their anti-tumor activity;inspired by TCM theory,we carefully explored the trace components of benzoin,discovered more structural types from benzoin,and revealed their anti-atherosclerotic activity.On the basis of previous research,this project takes the disease of " stroke phlegm syncope,sudden syncope " of benzoin as the starting point to further investigate the chemical constituents and neuronal protective activity of ethyl acetate extract of benzoin.Twenty-four monomer components were isolated from the ethyl acetate extract of benzoin by various chromatographic separation met hods such as silica gel,MCI,YMC pack ods-A,Sephadex LH-20 an d pre HPLC,and their chemical structures were determined by means of various spectral methods including 1D NMR and 2D NMR.Amo ng them,13 compounds are new compounds that have not been repo rted in the literature,19,21-dihydroxy-28-norolean-12-en-3-one(1),28-Norolean-12-ene-3,19-diol(2),12,19-epoxy-3β-hydroxy-28-norolean-12,18-dien-11-one(3),3β-hydroxyolean-11,13(18)-dien-19β,28-olide(5),3β,6β-dihydroxyolean-11,13(18)-dien-19β,28-olide(6),3β-hydroxyolean-11-en-19β,28-olide(7),(2S,3S)-3-(4-hydroxy-3-methoxyphenyl)-2-(R)-(4-hydro xy-3-methoxyphenyl)(methoxy)methyl)pent-4-en-1-yl benzoate(13),(2S,3S)-3-(4-hydroxy-3-methoxyphenyl)-2-(S)-(4-hydroxy-3-methoxypheny l)(methoxy)methyl)pent-4-en-1-yl benzoate(14),(2,5-bis(4-hydroxy-3-m ethoxyphenyl)-4-((4-hydroxy-3-methylphenyl)(methoxy)methyl)tetrahydr ofuran-3-yl)methyl benzoate(15),3-(4-hydroxy-3-methoxyphenyl)-3-met hoxypropyl benzoate(16),3-ethoxy-3-(4-hydroxy-3-methoxyphenyl)prop yl benzoate(17),(7S,8R,10R)-5-(3-Ethoxymethyl-5-methoxytetrahydro-fu ran-2-yl)-2-methoxy-phenol(18),(7S,8R,10S)-5-(3-Ethoxymethyl-5-metho xy-tetrahydro-furan-2-yl)-2-methoxy-phenol(19),28-norolean-12-en-3β,17β-diol(4),euscaphic acid(8),myricadiol(9),3β,6β,19α-trihydroxy-12-oleanen28-oic acid(10),salicylic acid(11),19α-hydroxy-3-oxoolean-12-ene-28-acid(12),dibutyl phthalate(20),p-hydroxybenzaldehyde(21),van illin(22),acetovanillone(23),carboxybenzene(24),1-3 are new nor-olea nane triterpenoids,5-7 are new oleanane skeleton triterpenes,and 13-14 are new lignans,15-19 are new phenylpropanoids.The neuronal protective activity of eight monomer compounds in benzoin was investigated in HT22 cells(mouse hippocampal neuronal cells)by using an oxygen and glucose deprivation(OGD)model.The results showed that the activity of some compounds was better than that of the positive drug edaravone at different concentrations,among which compounds 12 and 15 showed the most significant protective effect on HT22 cells damaged by oxygen and glucose deprivation.Through the development of this project,new terpenoids and new phenylpropanoids in benzoin were discovered,which enriched the chemical composition of benzoin,and we found that the monomer components in benzoin had relatively good protective effects against oxyglucose deprivation injury,which laid a solid foundation for the subsequent in-depth study of the neuroprotective mechanism of benzoin and its clinical use.