Oxytropis Falcata Research Articles

Anti-inflammatory, Antioxidant and Cytotoxic Activities of Flavonoids from Oxytropis falcata Bunge

AimTo evaluate the antioxidant and anti-inflammatory activities of flavonoid compounds isolated from Oxytropis falcata Bunge. MethodsFlavonoid compounds were evaluated for antioxidant activities on the total antioxidant activities, DPPH and superoxide radical-scavenging activities, for their cytotoxic and anti-inflammatory activities on the inhibition on LPS-induced NO production in RAW 264.7 cells. ResultsBy the analysis of HPLC-DAD, four flavonoid compounds, 2', 4'-dihydroxy chalcone (1), 7-hydroxy flavonone (2), 5, 7-dihydroxy-4'-methoxy flavonol (3) and 5, 7-dihydroxy-4'-methoxy flavone-3-O-β-D-galactoside (4), were isolated, identified and quantified. 4 was isolated for the first time from this plant. 1 and 2 displayed better NO inhibitory abilities in LPS-induced RAW 264.7 cells and 3 had the strongest free radical-scavenging activities in vitro. Conclusion3 as well as 1 and 2 could contribute, at least in part, to the anti-inflammatory properties of O. falcata, which could be used as marker compounds in the standardization.

Flavonoids in the Poisonous Plant Oxytropis falcata

Three new flavonoids, oxytropisoflavans A (1) and B (2) and (6aR,11aR)-3,8-dihydroxy-9,10-dimethoxypterocarpan (3), together with 30 known flavonoids (4-33), were isolated from the aerial parts and roots of Oxytropis falcata. The absolute configurations of 3 and C-3 in 1 and 2 were deduced by circular dichroism. The structure of flavonoid 2 was confirmed by single-crystal X-ray diffraction analysis and that of flavonoid 3 by total synthesis of its racemate. Oxytropisoflavan A (1) is an unprecedented chalcan-isoflavan biflavonoid, whereas oxytropisoflavan B (2) possesses a rare modified A-ring. Pterocarpan 3 has good radical-scavenging activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay.

Anti-inflammatory and Antioxidant Activities of Oxytropis falcata Fractions and Its Possible Anti-inflammatory Mechanism

Aim Alkaloid (AF), essential oil (EOF), flavonoid (FF), saponin (SF) and polysaccharide (PF) fractions obtained from Oxytropis falcata Bunge were investigated for their anti-inflammatory and antioxidant activities in vivo and in vitro for the first time. Method Two anti-inflammatory animal models (TPA- and carrageenin-induced) and three antioxidant models (total antioxidant activity, DPPH and hydroxyl radical-scavenging activity) were employed to evaluate the anti-inflammatory and antioxidant activities of O. falcata fractions. Animal models of acute inflammation and subacute inflammation were adopted to probe the possible anti-inflammatory mechanism. Results Flavonoids were major active constituents responsible for the anti-inflammatory and antioxidant activities of O. falcata. The anti-inflammatory mechanism of FF may be due, at least in part, to the inhibition of PGE 2 levels, decrease of MDA levels and enhancement of SOD, CAT and GSH-Px activities without inducing any gastric damage. Conclusion The results provide evidence to support the folk medicinal utilization of O. falcata for the treatment of inflammation.

Oxytrofalcatins A–F, N-benzoylindole analogues from the roots of Oxytropis falcata (Leguminosae)

Indole alkaloids, oxytrofalcatins A–F ( 1– 6), together with five other known alkaloids ( 7– 11), were isolated from the roots of Oxytropis falcata. Their structures were elucidated by comprehensive spectroscopic analyses, including using 1D and 2D NMR spectroscopy and mass spectrometry. This is the first report of N-benzoylindoles from a natural source. Compounds 1– 6 lacked significant cytotoxicity against SGC-7901 and HL-60 tumor cell lines.

24-Hydroxyoleanane-Type Triterpenes from the Aerial Parts and Roots of Oxytropis falcata

Phytochemical investigation of the aerial parts of Oxytropis falcata led to the isolation of three new 24-hydroxyoleanane-type triterpenes (1-3), seven known analogues (4-10), and two rare sesquiterpenoids (12, 13). Compounds 6 and 12 were isolated as new natural products. Triterpenes (5, 6, 8, 11) were isolated from the roots of O. falcata. The structures and relative configurations of these compounds were elucidated by spectroscopic analyses, including 1D and 2D NMR spectroscopy and mass spectrometry, and by comparison of their NMR data with those of related compounds. Single-crystal X-ray diffraction analyses confirmed the structures of 1-4, and the absolute configuration of 3 was evidenced by the incorporation of DMSO (crystallization solvent) in the crystal lattice.

Screening for fractions of Oxytropis falcata Bunge with antibacterial activity

Preliminary studies with the four extracts of Oxytropis falcate Bunge exhibited that the chloroform and ethyl acetate extracts showed stronger antibacterial activities against the nine tested Gram-positive and Gram-negative bacteria. The HPLC-scanned and bioassay-guided fractionation led to the isolation and identification of the main flavonoid compounds, i.e. rhamnocitrin, kaempferol, rhamnetin, 2′,4′-dihydroxychalcone and 2′,4′,β-trihydroxy-dihydrochalcon. Except 2′,4′,β-trihydroxy-dihydrochalcon, four other compounds had good antibacterial activities. The minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of the four compounds ranged between 125 and 515 µg mL−1. Staphylococcus aureus was the most susceptible to these compounds, with MIC and MBC values from 125 to 130 µg mL−1. This is the first report of antibacterial activity in O. falcate Bunge. In this study, evidence to evaluate the biological functions of O. falcate Bunge is provided, which promote the rational use of this herb.

Crystal Structure and Absolute Configuration of Pendulone

The complete structure of the title compound, C17H16O6, isolated from the roots of Oxytropis falcata Bunge, was confirmed unambiguously by a single-crystal X-ray analysis. The absolute configuration was established by circular dichroism (CD). The bond distances and angles are within the expected ranges. The quinone ring is linked to the chroman ring by C(3) at an equatorial position. The crystal structure is also stabilized by intermolecular hydrogen bonds.