| "Xiangjiapi", the root of Asclepiadaceae and Peiploca sepium Bge.,is now widely cultivated as a medicinal and ornamental plant in most provinces of China.It has been recorded in the Pharmacopoeia of the P.R.China for treating congestive heart failure and rheumatic arthritis.For the sake of the better use of this medicine, this paper describes the isolation, structural determinations and the contents analysis of major compounds in the dried root bark of Peiploca sepium Bge.Extraction and SeparationDried root bark (5kg) of Peiploca sepium were extracted with hot water (75L, 60L, 45L, respectively) for three times (3h, 2h, 1h, respectively). The extracted solution was absorbed by AB-8 macroporous adsorption resin, then eluted with 95%EtOH. The extraction was subjected to silica gel column chromatography using methanol-ethylacetate and methanol-chloroform as mobile phase repeatedly to afford A,B and C。The extraction( A,B and C) was subjected to ODS column chromatography using methanol-water as mobile phase to afford X6, X7, X1, X4 and X2 respectively.Compounds X1-X7 were identified respectively by IR, MS and 1DNMR as Periplocin, glycosideH1, 4-methoxysacylaldehyde, Methyl 4-o-(2-o-acetyl-β-D- digitalo -pyranosyl)-β-D-cymaropyranoside, ursolic acid ,β-sitodterol and oleanolic acid.Determination of Periplocin and glycoside H1 in Xiangjiapi by HPLCIn this paper we present a more sensitive quantification method by HPLC-ELSD for measuring the main saponins (X1 and X2) in the dried root bark of Peiploca sepium Bge.. HPLC was performed on an Agilent 1200 HPLC instrument and Eclipse XDB-C18 column (4.6×250 mm, 5μm) with the rate of 1.0mL.min-1at 25℃,using acetonitrile and water as mobile phase (gradient, 015min, 25:75; 2740 min, 45:55); The gas(air) pressure of ELSD was 2.5mL.min-1 and the temperature of drift tube for measurement was 102℃.Results:ⅰThe linearity was in the range of 2.0-20.0μg for X1, X2 and the correlation coefficients were 0.9995 and 0.9994,respectively. Y=0.9405X+5.4709 r = 0.9995 Y=0.9814X+5.8548 r = 0.9994ⅱWe injected the solution of X1, X2 into HPLC six times and the results of precision tests is RSD<2%.ⅲWe measured the contents of X1, X2from the dried root bark of Peiploca sepium Bge.and the results are RSD<2% respectively.ⅳThe stability of X1, X2is good in ten hours because the results are RSD<2% .ⅴThe average recoveries (n=6) X1 for, X2 are101.5% ( RSD=1.45% ) and 97.2% (RSD=1.13% ) respectively.ⅵThe average contents of X1, X2 of Peiploca sepium Bge.purchased from Anguo of Hebei province were determined by the above methods, the results showed that The average contents of X1, X2 were 0.35%,0.17% respectively .The results of this paper can offer a new index on content determnation for the development and utilization of the root bark of Peiploca sepium Bge.. |
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