Chemical Constituents Of Rodgersia Aesculifolia And Their Bioactivities

The rhizome of Rodgersia aesculifolia is the dry rhizome of Rodgersia aesculifolia which belongs to Saxifragaceae family. It is an effective medicine for eliminating toxic heat, stopping bleeding and diarrhea and used for the treatment of diarrhea, traumatic bleeding, leukorrhagia, swollen sore throat, rectocele, metroptosis, et al. In order to make the herb can be fully development and utilization, this paper studied on the chemical components of Rodgersia from Shaanxi Taibai mountain area systematicall. The antimicrobial properties and biological activities of the chemical components were tentative researched.The extracting solution was obtained by extracting Rodgersia aesculifolia coarse powders (3.0 Kg) with 95% ethanol at room temperature, soaking for 24 hours every time. After vacuum concentration, the ethanol extracts (474 g) were eluted using petroleum ether, ethyl acetate and methyl alcohol by silica gel column chromatography, respectively. The crude extracts in petroleum ether, ethyl acetate and methyl alcohol were 7 g,123 g and 326 g, respectively. The crude extracts were further separated and purified by macroreticular resin, silica gel column chromatography, gel column chromatography, et al. Twelve compounds were obtained. The chemical structures of the twelve compounds were authenticated using nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry with the physical and chemical properties. The twelve compounds were identified as followed:β-sitosterol (1), ergosterol (2), p-hydroxybenzoic acid (3),3β-Hydroxyolean-12-en-27-oic acid (4), succinic acid (5), methyl malic acid (6), gallic acid (7), catechin (8), bergenin (9), daucosterol (10), n-butyl-βD-fructopy-ranoside (11), isoquercitrin (12). Compound 3,4,5,6,11 and 12 are first isolated from the plant, and that the compound 4,6 and 11 from the genus for the first time.The minimal inhibitory concentrations of the 12 pure chemicals were tested by double-dilution method. The 4 germ as testing strains were Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and streptococcus lactis. The 10 plant pathogenic fungi as testing strains were Cytospora mandshurica, Colletortrichum gloeosporioides, Alteraria alternate, Gibberella saubinerii, Setosphaeria turcica, Sclerotinia sclerotiorum, Alternaria brassicae, Phytophthora capsici, Botrytis cinerea and Peony anthracnose. Compared with the positive control, the results of inhibitory bacteria showed that 9 of the 12 compounds had different inhibiting effect on the 4 germ. Compound 4 had strong inhibition on the Gram-negative bacterium, especially on Escherichia coli with the minimal inhibitory concentration of 15.6 μg·mL-1. Compared with the positive control, the results of inhibitory fungi showed that 8 of the 12 compounds had different inhibiting effect on the 10 plant pathogenic fungi. Compound 4 had strong inhibition on the plant pathogenic fungi almostly. Bacteriostatic experiment results showed that the compound 4 had strong broad-spectrum antibacterial activity.The antioxidant activities of compound 3,5,6,7,8 and 10 were studied by testing the clearance rate of DPPH free radicals. The results showed that the antioxidant activities of gallic acid, isoquercetin and catechin were strong, p-hydroxybenzoic acid had certain antioxidant activity. However, 3β-Hydroxyolean-12-en-27-oic acid and bergenin had a little antioxidant activities.