Study On The Distribution Of Triterpenoids In White Birch Bark

White birch(Betula platyphylla)is a deciduous broadleaf tree of Family Betulacea,has abundant of betulin acid,betulin and lupeol.In this research,a simple procedure is described for the simultaneous extraction and determination of betulin acid,betulin and lupeol in the white birch bark.In this paper the distribution in organs,seasonal and store time of terpenoids in mature trees of White birch were studied.1.A simple,rapid and sensitive method for the determination of terpenoids content in White birch was established.Terpenoids was ultrasonically extracted with 100%alcohol for 100min,and determined by high performance liquid chromatography.The terpenoids were separated on a Thermo Hypersil GOLD C18 column(250 mm×4.6 mm,5μm),and at flowrate 1.2 mL/min and detective wavelength 210 nm.The solvent gradient program was as follow:A: water(0.1%acetic acid)/B:acetonitrile(0.1%acetic acid)increased linearly from A/B=9/1 to A 100%in the first 10 min,then isocratic for 13 min,acetonitrile/water(0.1%acetic acid) decreased linearly from A100%to A/B=9/l in 2min;at time 30 min,stopped the program.2.Betulin acid,betulin and lupeol contents of White birch changed in a small scale with the store time of room temperature(0～120 h).The fluctuated range of betulin acid contents was about 9.32 mg/g~10.57 mg/g.The fluctuated range of betulin contents was about 25.20 mg/g~238.94 mg/g.The fluctuated range of lupeol contents was about 5.77 mg/g~6.61 mg/g.3.The terpenoids contents had no signficant difference among the different height in the trunk bark of white birch in mature trees.The content of betulin acid was about 8.30 mg/g~ 10.40 mg/g.The content of betulin was about 176.68 mg/g~216.09 mg/g.The fluctuated range of lupeol contents was about 11.43 mg/g~13.12 mg/g.4.The terpenoids contents had no signficant difference among the different radial parts in the trunk bark of white birch in mature trees.The fluctuated range of betulin acid contents was about 31.18 mg/g~32.64 mg/g.The fluctuated range of lupeol contents was about 3.00 mg/g~ 3.11 mg/g.The content of betulin was decline follow the radial parts from outside to inside. The contents of radial parts outside was the highest(248.98 mg/g),and the contents of radial parts inside was the lowest(209.93 mg/g).5.Betulin acid,betulin and lupeol contents of White birch changed in a small scale with the season changing in the secondary forest.The fluctuated range of betulin acid contents was about 7.83 mg/g~9.75 mg/g.The fluctuated range of betulin contents was about 151.03 mg/g ~ 174.44 mg/g.The fluctuated range of lupeol contents was about 7.86 mg/g ~ 9.26 mg/g.