A New Cyclic Triterpene Saponin from Phyteuma japonicum

Abstract

A new cyclic triterpene saponin, phyteujaposide (1) and eight known compounds (2-9) were isolated from the leaves of Phyteuma japonicum. The structure of the new compound (1) was elucidated by 1D and 2D data analysis, acid hydrolysis and GC-MS. Compounds 7 and 9 potently inhibited the NO production in LPS-activated BV-2 cells and compounds 5 and 6 showed a significant secretion induction of NGF in C6 glioma without cell toxicity. Phyteuma japonicum Miquel (Campanulaceae), commonly known as horned rampion, is a perennial herb widely distributed throughout Korea, China, and Japan. The young leaves of this plant are as a salad raw consumed in Korea and many plant of Campanulaceae family were used as an herbal drug to treat bronchitis, inflammation, asthma, pulmonary tuberculosis, and ear-pains. In previous phytochemical studies, phenolic compounds, flavonoids and triterpene saponins were isolated from Phyteuma genus, and some of them showed antioxidant activity. However, no phytochemical and biological investigations have been reported on the secondary metabolites of this species. The medicinal importance of the species and the lack of information with regards to its chemical constituents prompted this investigation of constituents of the leaves of P. japonicum. In our screening test, the MeOH extract of P. japonicum exhibited inhibitory activity for the nitric oxide (NO) production HETEROCYCLES, Vol. 89, No. 8, 2014 1913