Isolation and characterization of flavonoids from the roots of medicinal plant Tadehagi triquetrum (L.) H.Ohashi

Abstract

Three flavonoid compounds were isolated from the roots of medicinal plant Tadehagi triquetrum (L.) H.Ohashi, also known as Desmodium triquetrum (Fabaceae). On the basis of the chemical and spectral analysis, the compounds were identified as baicalein (Flavone), naringin and neohesperidin (Flavonone). To the best of our knowledge and based on the literature survey all three compounds were first time reported from this medicinal plant.

     

A new lignan from Gynostemma pentaphyllum

A new lignan ligballinone 1 with the know ligballinol 2 were isolated from plant Gynostemma pentaphyllum.Their structures were determined through spectroscopic methods including ESI-MS,1D and 2D NMR (1H,13C,DEPT,1H-1H COSY,HMQC,RMBC) and X-ray diffraction experiment for 2.     

A new lignan from Oxytropis myriophylla

The 70% alcohol extract of Oxytropis myriophylla (PALL.) DC. (Leguminosae) exhibited high radical scavenging activity (IC(50) value: 88.0?μg?mL(-1) and 86.7?μg?mL(-1)) on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays. Further chemical investigation led the isolation of one new lignan, namely myriophylloside G (1), together with three known compounds. Their structural elucidations of all the compounds were based on extensive spectroscopic methods, including HRESIMS and 2D NMR experiments (HSQC, HMBC and (1)H-(1)HCOSY) and by comparison with reference values.     

Phenylpropanoid glucosides from Tadehagi triquetrum inhibit oxLDL-evoked foam cell formation through modulating cholesterol homeostasis in RAW264.7 macrophages

The phenylpropanoid glucosides from Tadehagi triquetrum were found to be beneficial to glucose and lipid metabolism in vitro. Herein, we investigated the effects of these compounds on oxidised low-density lipoprotein (oxLDL)-induced foam cell formation in RAW264.7 macrophages, aiming to evaluate their potential utility in prevention of atherosclerosis. Our results showed that three out of seven phenylpropanoid glucosides significantly inhibited oxLDL-evoked foam cell formation. These three compounds remarkably inhibited cholesterol influx and enhanced cholesterol efflux. Treatment with compounds 3, 4 and 7 significantly down-regulated the expression of scavenge receptors 1 (SR-1) and cluster of differentiation 36 (CD36) and increased the expression ATP-binding cassette transporters A1 and G1 (ABCA1 and ABCG1). Analyses of structure–activity relationships revealed that cinnamyl group was the most pivotal group for their activities. This work provided phenomenon that these phenylpropanoid glucosides are effective regulator of cholesterol influx/efflux and may be useful in leading for development of anti-atherosclerotic agents.     

A new aryltetrahydronaphthalene lignan from Epimedium brevicornum

A new aryltetrahydronaphthalene lignan,(+)-cycloolivil formaldehyde condensate(1),was isolated from the whole plants of Epimedium brevicornum(Berberidaceae).Its structure was elucidated on the basis of MS,1D and 2D NMR techniques.     

A new pinoresinol-type lignan from Ligularia kanaitizensis

A new pinoresinol-type Lignan, 9alpha-angloyloxypinoresinol (1), was isolated from the roots and rhizomes of Ligularia kanaitizensis (Franch.) Hand.-Mazz, in addition to a known compound, 9alpha-hydroxypinoresinol (2). The structure of this new lignan (1) was established on the basis of 1D and 2D NMR experiments. Anti-HIV-1 RT biological assay showed that 1 was inhibitory to HIV-1 RT.     

A new cyclobutane lignan from Cinnamomum balansae

A new cyclobutane lignan, named cinbalansan (6), was isolated from the leaves of Cinnamomum balansae, along with five known compounds, 1,2-dimethoxy-4-(1-E-propenyl)benzene (1), 1,2-dimethoxy-4-(1-Z-propenyl)benzene (2), 1,2-dimethoxy-4-(2-propenyl)benzene (3), 3,4-dimethoxybenzaldehyde (4), and E-(3,4-dimethoxyphenyl)-2-propenal (5). The structure of cinbalansan was shown to be 1beta,2beta,3alpha,4alpha-1,2-dimethyl-3,4-bis(3,4-dimethoxyphenyl)cyclobutane by a combination of 1H-, 13C-NMR, and NOE- experiments and by direct analysis of the 1H-NMR spectrum by the method of X-application.     

A new furofuran lignan from Piper terminaliflorum Tseng

The chemical investigation of whole plants Piper terminaliflorum Tseng led to the isolation of one new furofuran lignan, 7-methoxyasarinin (1), along with three known amide alkaloids (2–4) as N-3,5-dimethoxy-4-hydroxycinnamoylpyrrole (2), dihydropipercide (3) and 1-[(2E,4E,9E)-10-(3,4-Methylenedioxyphenyl)-2,4,9-undecatrienoyl]pyrrolidine (4). Their structures were elucidated by extensive spectroscopic analyses, including 1D, 2D NMR and HR-ESI-MS, and by comparison with the literature. Compounds (2–4) were isolated from Piper terminaliflorum Tseng for the first time. All isolated compounds (1–4) were evaluated for their cytotoxic activities against five human cancer cell lines (including A-549, SMMC-7721, HL-60, MCF-7 and SW-480).     

A new lignan from the seeds of Sphaerophysa salsula

A novel lignan: sphaerophyside SC was isolated from ethanolic extract of the seeds of Sphaerophysa salsula (Pall.) DC. The structure of the compound was elucidated mainly on the basis of the 1D NMR and 2D NMR data.     

Potential hypoglycemic effect of acetophenones from the root bark of Cynanchum wilfordii

Three new acetophenones, named cynwilforones A–C (1–3), together with cynandione A (4) were isolated from the root bark of Cynanchum wilfordii (Maxim.) Hemsl. Their structures were deduced based on spectroscopic analysis and chemical methods. Compounds 1 and 4 exhibited potential hypoglycemic effects through inhibition of hepatic gluconeogenesis by down-regulating the expression of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. This is the first report that acetophenones from the root bark of C. wilfordii possesses potential hypoglycemic activity in vitro.     

A novel lignan glycoside with antioxidant activity from Tinospora sagittata var. yunnanensis

A novel lignan glysocide, namely sagitiside A (1), together with two known ones, (+)-lyoniresinol-2α-O-β-D-glucopyranoside (2) and (+)-5'-methoxyisolariciresinol 3α-O-β-D-glucopyranoside (3), was isolated from the 95% ethanol extract of dry roots of Tinospora sagittata var. yunnanensis. The structure of the new compound (1) was determined based on MS, 1D and 2D NMR spectral data. Compounds 1-3 showed antioxidant activity with EC(50) values 55, 75 and 80?μM by 1,1-diphenyl-2-picryhydrazyl (DPPH) radical-scavenging assay.     

A new lignan and other constituents from Zanthoxylum armatum DC

A new lignan (1), named armatumin, along with 25 known compounds, was isolated from Zanthoxylum armatum. The structure of compound 1 was elucidated using spectroscopic methods. Compounds 7, 8, 11, 13, 16, 20 and 21 were first isolated from Z. armatum and compounds 14 and 19 were isolated for the first time from Rutaceae.     

A new lignan glycoside and other constituents from Cephalaria ambrosioides

A new lignan glycoside, 1,5-dihydroxy-2-(4"-beta-D-glucopyranosyloxy-3"-methoxyphenyl)-6-(4'-hydroxy-3'-methoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane, named ambrosidine ([structure: see text]), along with seven known compounds (four iridoids and three hydroxycinnamic esters) were isolated from the roots of Cephalaria ambrosioides. The structures of these compounds were determined by use of NMR and MS techniques and by chemical transformations. The cytotoxic activity of the novel compound [structure: see text] was evaluated against five human solid tumour cell lines.     

A new lignan glycoside and phenylethanoid glycosides from Strobilanthes cusia BREMEK

The root of Strobilanthes cusia BREMEK. (Acanthaceae), popularly known as Da-Ching-Yeh, has been commonly used in traditional Chinese medicine. It is used to treat influenza, epidemic cerebrospinal meningitis, encephalitis B, viral pneumonia, mumps, and severe acute respiratory syndrome (SARS). In this study, we found a new lignan glycoside (6) and two new phenylethanoid glycosides (7, 8) together with five known compounds as chemical constituents of Strobilanthes cusia root. Some samples were examined for anti-herpes simplex virus type-1 (HSV-1) activity. Among the tested samples, lupeol showed anti-HSV-1 activity (EC(50): 11.7 microM) and showed 100% inhibition of virus plaque formation at 58.7 microM.     

Two new benzofuran lignan glycosides from Gelsemium elegans

Two new benzofuran lignan glycosides, gelsemiunoside A and B, were isolated from the whole plant of Gelsemium elegans Benth. Their structures were elucidated on the basis of spectroscopic evidence. Furthermore, gelsemiunoside A and B were shown a potent cytotoxic activity by suppressing the proliferation of A375-S2 cells.     

A new lignan rhamnoside from Bauhinia retusa seed pods(Caesalpiniaceae)

A new lignan rhamnoside identified as 2,6-di(4’,5’-dihydroxyphenyl)-3,7-dioxabicyclo[3.3.0]octane-1-hydroxy-5-O-rhamnopyranoside (1) has been isolated from the ethanolic extract of seed pods of Bauhinia retusa.Its structure was established by extensive spectroscopic techniques(UV,IR,1D NMR,2D NMR,HRESIMS).     

A new lignan derivative from the root of Ilex pubescens

One new compound, ilexlignan A （1）, was isolated from the root of llex pubescens. Its structure was elucidated by the combination of one- and two-dimensional NMR analysis, mass spectrometry, CD spectrum measurement and chemical evidence.