Reynoutria japonica and R. sachalinensis have been used as medicinal resources in Korea. However, it is difficult to identify and determine these medicinal herbs correctly because they are usually customized and purchased as the fragmented rhizomes types. To develop molecular markers for distinguishing two species, we analyzed and compared the chloroplast DNA sequences of seven loci (atpB, matK, ccD-psaI, atpF-H, trnL-trnF, psbK-I and rpl32-trnL). Among them, we found two effective SNPs in psbK-I region for R. japonica and atpF-H region for R. sachalinensis. Based on these SNP sites, we designed the new R. japonica- specific primer which is able to amplify 300 bp fragment in psbK-I region. A similar strategy was applied for the atpF-H region of R. sachalinensis. These molecular markers would be successfully applied to recognize R. japonica and R. sachalinensis.

Five known anthraquinones, physcion (1), I-O-methylemodin (2), emodin (3), physcion-8-O-β,-D-glucopyranoside (5), emodin-8-O-β,-D-glucopyranoside (6) and two known stilbenes, trans-resveratrol (4), trans-resveratrol-3-O-β,-D-glucopyranoside (7) were isolated from MeOH extract of Reynoutria sachalinensis (Polygonaceae). All structures were unambiguously established by 1D and 2D NMR and MS data and the compounds were evaluated for their cytotoxicity against L1210, HL-60, BI6F10 tumor cell lines in MTT assay. Among the compounds, trans-resveratrol (4) exhibited significant cytotoxic activity with IC50 values of 9.2, 6.7 and 9.8 μg/ml, against the test cell lines respectively, but compounds 1-3 exhibited the moderate cytotoxic activity.