Study Of Medicinal Plants Of Ampelopsis By DNA Molecular Identification And Chemical Composition Analysis

In this study,medicinal plants of Ampelopsis and their related species including 21 species、125 parts of experimental samples were identified by ITS2 and psbA-trnH sequences,the identification efficiency of these two sequences was evaluated via analysis of sequence variation、calculation of genetic distance and construction of NJ tree,and the experimental results are as follows:(1)After DNA extraction 、 amplification 、 sequencing and sequence verification,65 ITS2 sequences and 122 psbA-trnH sequences were obtained;the samples of Ampelopsis megalophylla 、 Ampelopsis grossedentata 、Ampelopsis cantoniensis、Cayratia and Vitis appeared the phenomenon of ITS2 sequence amplification-difficult.(2)The ITS2 sequence length of Ampelopsis samples were 243 bp after the alignment,that of Tetrastigma samples was 251~254bp;the psbA-trnH sequence length of Ampelopsis megalophylla、Ampelopsis grossedentata and Ampelopsis cantoniensis were 243~287bp,that of other species of Ampelopsis、Vitis、Cayratia and Tetrastigma were 353~359bp、324bp、316~319bp and 334 bp respectively;the variable sites of these two sequences are both scant and unstable.(3)With the ITS2 sequence,the maximum intraspecific genetic distance of Ampelopsis glandulosa 、 Ampelopsis glandulosa var.heterophylla 、Ampelopsis delavayana 、 Ampelopsis glandulosa var.kulingensis 、Ampelopsis japonica were 0.021、0.004、0.004、0.008、0,the minimum interspecific genetic distance of that were 0、0、0、0、0.029.With the psbA-trnH sequence,the maximum intraspecific genetic distance of Ampelopsis megalophylla 、 Ampelopsis grossedentata 、 Ampelopsis cantoniensis、Ampelopsis glandulosa、Ampelopsis glandulosa var.hancei、Ampelopsis glandulosa var.heterophylla、Ampelopsis delavayana、Ampelopsis glandulosa var.kulingensis、Ampelopsis japonica were 0.040、0.004、0.008、0.006、0、0.006、0.008、0.009、0,the minimum interspecific genetic distance of that were both 0.(4)Construction of NJ tree,the NJ tree of ITS2 sequence showed that,the overall was divided into two branches,one branch was the 2 samples of Tetrastigma,another branch was all samples of Ampelopsis;within the branch of Ampelopsis,Ampelopsis japonica standed alone,the other species gathered together.The NJ tree of psbA-trnH sequence showed that,the overall was divided into two branches too,one branch was Cayratia and Tetrastigma,another branch was Ampelopsis and Vitis;within the branch of Ampelopsis,Ampelopsis megalophylla 、 Ampelopsis grossedentata 、 Ampelopsis cantoniensis gathered together and the other 12 species gathered together,there was no independent species.The chemical composition of Ampelopsis medicinal pants and their related species including 10 species 、 33 parts of experimental samples were comparative analysised using HPLC.The HPLC conditions was Agilent TC-C18 column,the mobile phase was Acetonitrile-0.1% aqueous phosphoric acid(v/v)gradient elution,the velocity of flow was 0.7mL/min,the column temperature was 25℃,the wavelength of detection was 265 nm,the injection volume was 20μL.The results showed that,different species of Ampelopsis contained different chemical composition,the same species from different areas were also differences in chemical composition;the species of Ampelopsis almost all contained Gallic acid 、 Myricitrin and quercetin-3-rhamnoside;Dihydromyricetin and Myricetin were only detected in Ampelopsis megalophylla 、 Ampelopsis grossedentata and Ampelopsis cantoniensis with relatively high content.