Studies On Chemical Constituents And Bioactivity Of Quercus Wutaishanica

Quercus wutaishanica Mayr is a kind of deciduous tree belonging to Quercus Fagaceae that grows chiefly in Shanxi,China.Quercus plants are widespread in Asia,Africa,Europe and America,with about 300 species and 51 species in China.According to the relevant literatures,the compounds isolated from the genus Quercus are triterpenoids,flavonoids,steroids,coumarins,alkaloids,coumarins,alkaloids,polyphenols and volatile oils.Modern pharmacological studies have shown that these chemical compositions have a variety of biological activities,such as antioxidant,antibacterial,anti-cancer,anti-senility,anti-inflammatory,antiviral and anti-complement.However,there are few researches on the chemical constituents and pharmacological activities of Q.wutaishanica,especially the research on its seeds has not been reported yet.In this study,the seeds of Q.wutaishanica were selected as the research object,and their chemical constituents were studied in order to further elucidate the biological active ingredients in the seeds of Q.wutaishanica and find new active lead compounds.Systematic phytochemical research on this medicinal plant provided 18compounds from its seeds by solvent extraction,macroporous resin column chromatography,normal and reverse phase silica gel column chromatography,TLC,polyamide column chromatography,Sephadex LH-20 column chromatography and ODS column chromatography,along with recrystallization.These compounds were identified by IR,UV,HR-ESI-MS,¹H NMR,¹³C NMR,HMBC,HSQC,DEPT,COSY,NOESY,and comparison with authentic samples,including 2 steroids[β-sitosterol（QLP-2）,Daucosterol（QLE-5）],11 polyphenols[Gallic acid（QLE-2）,Methyl gallate（QLE-6）,Ethyl gallate（QLE-1）,Ellagic acid（QLB30-1）,3,3’,4-Tri-O-methylellagicacid-4’-O-β-D-galactopyranoside（QLE-4）,Decarboxylated ellagic acid（QLE-14）,Brevifolin（QLE-8）,Ethyl brevifolincarboxylate（QLE-7）,Pentagalloylglucose（QLE-13）,Ethyl castavaloninate（QLB30-2）,EIlagic acid4’-O-xylopyranoside（QLB70-1）],4 lignans[（-）-7,7’-Dioxodihydroguaiaretic acid（QLE-9）,（-）-Pinoresinol（QLE-10）,（-）-Dihydrodehydrodiconiferyl alcohol（QLE-11）,（+）-Isolariciresinol（QLE-12）]and 1 other type compound[g-Tocopherol（QLP-1）].Among the 18 compounds,QLB30-2 was a new compound,and QLP-1,QLE-4,QLE-5,QLE-7,QLE-8,QLE-9,QLE-10,QLE-11,QLE-12,QLE-14 and QLB70-1were reported for the first time in the genus Quercus.It is worthy to be mentioned that among these compounds,compounds QLE-1,QLE-2,QLE-6 QLE-7,QLE-13,QLE-14,QLB30-1 and QLB30-2 exhibited potent DPPH radical-scavenging activity,compounds QLE-7,QLE-13,QLE-14 QLE-7,QLB30-1 and QLB30-2 exhibited potentα-glucosidase inhibitory activity.These results provide new insights into the role of seeds of Q.wutaishanica in the antioxidant and antidiabetic drug,and may support to the development of it as a health-promoting food.