Platycodon grandiflorum is a species of herbaceous flowering perennial plant of the family Campanulaceae. The major ingredients are platycosides, terpenoid saponins. It contains 1-4 % of the dry weight and there are about 20 types of platycosides. Among them, platycodin D have various pharmacological effects on cough and cold. Platycosides are synthesized from oleanane by mevalonic acid pathway and cytochrome P450s and UGTs are important enzymes in the saponin biosynthesis. UGT is glucose transfer enzyme and act on the final step of the secondary metabolite biosynthesis. In this study, we tried to identify UGT genes involved in saponin biosynthetic pathway from the various tissues of P. grandiflorum and non germinated seeds using RNA-seq analysis. The sequencing was performed using Illumina Hi-Seq platform after cDNA library preparation. The produced reads were assembled using CLC Genomics Workbench software (CLC Bio, Inc.). We obtained 122,663 contigs and found 137 putative UGT genes. The phylogenetic relationship was analyzed and putative genes related to platicoside biosysthesis were selected and cloned for further analysis.

Four compounds were isolated from Suaeda japonica by repeated column chromatography. Their structures were identified as 2'-hydroxy-6,7-methylenedioxy-isoflavone (1), loliolide (2), dehydrovomifoliol (3), and uridine (4) by spectral analysis and comparison with the published data. All compounds were isolated for the first time from this plant.