Study On Chemical Constituents From The Flower And The Seed Cake Of Paeonia Rockii

Paeonia rockii (P. rockii), the wild relative of cultivated peony, belongs to the deciduous sub-shrub of Paeonia. The flower of P. rockii is esculent. The seed oil of P. ostii contains abundant unsaturated fatty acids with important healthy and medicinal values. Our previous studies have confirmed the antibacterial effect of the seed cake of P. rockii. It is thus important to further study chemical constituents from the flower and the seed cake of P. rockii.To study active constituents within the flower and the seed cake of P. rockii, chemical constituents were isolated firstly by Toyopearl HW-40, Sephadex LH-20, preparative HPLC and silica gel column chromatographies. The structures were then elucidated on the basis of spectral data analysis.Structures of those compounds from flowers of Paeonia rockii are elucidated as follws:3,5-dihydroxy-4-methoxybenzoicacid (I), dihydrokaempfer (II), apigenin-7-O-β-D-glucoside (III), apigenin-7-O-β-D-neohesperidoside (IV), kaempferol-3-O-β-D-glucopyranoside-7-O-β-D-glucopyranoside (V) and kaempferol-7-O-β-D-glucopyranoside (VI). All of isolated compounds were identified from the flower of P. rockii for the first time.The structure of compounds from the seed cake of P. rockii are elucidated as follws: p-hydroxybenzaldehyd (1), Oleanolic acid (2), Betulinic acid (3), hederagenin (4), Daucosterol (5), trans-ε-Viniferin (6), cis-ε-Viniferin (7), Pauciflorol E (8),(+)-ampelopsin B (9), Hopeafuran (10), Vitisinol C (11), Gnetin H (12), Suffruticosol A(13), Suffruticosol B (14), Suffruticosol C (15), Rockiol A (16), Rockiol B (17), Rockiol C (18),4-O-Methylpaeoniflorin (19), Paeonidanin (20) and4,9-dihydroxy-8,10-dehydrothymol-1-O-β-D-glucosides (21). Compound16,17,18and21were new, and the other ones were identified from the seed cake of P. rockii for the first time.The Stilbene compounds form the seed cake of P. rockii presented inhibition activities in antibacterial experiments. The compound6and12have the strongest activity. This research provides a scientific basis for searching new antibacterial substances.