A new isoflavone glycoside from Ceiba pentandra (L.) Gaertner

From the 80% EtOH extract of the bark of Ceiba pentandra (L.) Gaertner, a new isoflavone glycoside was isolated along with known isoflavones, vavain and vavain glucoside. The structure was elucidated by spectroscopic analysis as 5-hydroxy-7,4',5'-trimethoxyisoflavone 3'-O-alpha-L-arabinofuranosyl(1-->6)-beta-D-glucopyranoside.     

Analysis and retention behavior of isoflavone glycosides and aglycones in Radix Astragali by HPLC with hydroxypropyl‐β‐cyclodextrin as a mobile phase additive

In order to determine isoflavone glycosides (calycosin‐7‐O‐β‐d ‐glucoside and formononetin‐7‐O‐β‐d ‐glucoside) and aglycones (calycosin and formononetin), a simple HPLC method with isocratic elution employing hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as a mobile phase additive was developed. Various factors affecting the retention of isoflavone glycosides and aglycones in the C₁₈ reversed‐phase column, such as the nature of cyclodextrins, HP‐β‐CD concentration, and methanol concentration, were systematically studied. The results show that HP‐β‐CD, as a very effective mobile phase additive, can markedly reduce the retention of isoflavone glycosides and aglycones, and the decrease magnitudes of isoflavone aglycones are more than those of their glycosides. The role of HP‐β‐CD in the developed HPLC method is attributed to the formation of the inclusion complexes between isoflavone glycosides (or aglycones) and HP‐β‐CD. So, the apparent formation constants of the isoflavone glycosides (or aglycones)/HP‐β‐CD inclusion complexes also were investigated. Isoflavone glycosides (and aglycones) form the 1:1 inclusion complexes with HP‐β‐CD, and the isoflavone aglycones/HP‐β‐CD complexes are more stable than the isoflavone glycosides/HP‐β‐CD complexes. Finally, the optimized method was successfully applied for the determination of isoflavone glycosides and aglycones in Radix Astragali samples.     

New cytotoxic isoflavone from the root bark of Brosimum utile

A new isoflavone 5,7,4'-trihydroxy-3'-(3-hydroxy-3-methylbutyl)isoflavone (isowigtheone hydrate) (1), together with six known isoflavones 2-7 and (-)epicatechin, were isolated from the root barks of Brosimum utile. Their structures were established on the basis of spectroscopic evidence. The in vitro cytotoxic activity of the new compound 1 was evaluated against cell lines MCF7 (human breast carcinoma), PC3 (human prostate carcinoma), HT29 (human colon cancer) and human dermis fibroblasts.     

Tricalysiosides P-U: Ent-kaurane glucosides and a labdane glucoside from leaves of Tricalysia dubia OHWI

Further extensive isolation work on the 1-BuOH-soluble fraction of a MeOH extract of Tricalysia dubia afforded five new ent-kaurane glucosides (4-8) and one new labdane glucoside (9), together with a known megastigmane glucoside, sammangaoside B (1), and monoterpene glucosides (2, 3). The structures of the new compounds were elucidated by analyses of one- and two-dimensional NMR spectroscopic data. The absolute configuration of the 9-position of sammangaoside B was revised to S and its total stereochemistry was established by the modified Mosher's method.     

Isoflavonoid glycosides from the rhizomes of Iris germanica

Four isoflavone glycosides were isolated from the rhizomes of Iris germanica. Compounds 1 and 2 are new, while compounds 3 and 4 are known isoflavone glycosides. These compounds were identified as iriskashmirianin 4'-O-beta-D-glucoside (1), nigricin 4'-O-beta-D-glucoside (2), irilone 4'-O-beta-D-glucoside (3) and iridin (4). Their structures were determined with the help of spectroscopic methods.     

Dalvelutinoside,a new isoflavone glycoside from the methanol extract of Dalbergia velutina roots

A new isoflavone glycoside, dalvelutinoside (1), together with one known isoflavone (2) and five known isoflavone glycosides (3–7) were isolated from the methanol extract of the roots of Dalbergia velutina. Their structures were determined by spectroscopic analysis. All isolated compounds were evaluated for their cytotoxicity against KB and HeLa cell lines.     

A new C9 nor-isoprenoid glucoside from Rantherium suaveolens

The new C(9) nor-isoprenoid 3-methyl-octa-1,5-diene-7-one-3-O-beta-D-glucopyranoside, named as ranthenone glucoside (1), together with the previously known 9-hydoxylinaloyl glucoside (2), sitosterol-3beta-O-[6'-palmitoyl-beta-D-glucopyranoside] (3), scopoletin (4), fraxetin (5), and scopolin (6), were isolated from the aerial parts of Rantherium suaveolens. The structures of these compounds were elucidated by extensive spectroscopic analysis.     

Isoflavones from Ficus nymphaefolia

A new isoflavone, 5,7-dihydroxy-4'-methoxy-3'-(2,3-dihydroxy-3-methylbutyl)isoflavone (1) was isolated from the stem bark of Ficus nymphaefolia Mill. (Moraceae) together with eight known isoflavones: genistein, erycibenin A, cajanin, 5,7,2'-trihydroxy-4'-methoxyisoflavone, erythrinin C, alpinumisoflavone, derrone and 3'-(3-methylbut-2-enyl)biochanin A. Their structures were established by spectral analysis including 1D and 2D NMR experiments.     

Water-soluble constituents of Glehnia littoralis fruit

From the water-soluble portion of the methanol extract of the fruit of Glehnia littoralis Fr. SCHMIDT ex MIQ. (Umbelliferae; "hamabofu" in Japanese), thirty compounds, including three new monoterpenoids and a new monoterpenoid glucoside, a new benzofuran glucoside, a new alkyl glucoside, and a new glucide, were obtained. Their structures were clarified by spectral investigation.     

Four new isoflavonoids from the stem bark of Erythrina variegata

Bioassay-directed fractionation of the stem bark extract of Erythrina variegata L. has resulted in the isolation of three new isoflavones: 5,4'-dihydroxy-8-(3,3-dimethylallyl)-2'-methoxyisopropylfurano[4,5:6,7]isoflavone (1), 5,7,4'-trihydroxy-6-(3,3-dimethylallyloxiranylmethyl)isoflavone (2), 5,4'-dihydroxy-8-(3,3-dimethylallyl)-2'-hydroxymethyl-2'-methylpyrano[5,6:6,7]isoflavone (3) and a new isoflavanone, 5,4'-dihydroxy-2'-methoxy-8-(3,3-dimethylallyl)-2',2'-dimethylpyrano[5,6:6,7]isoflavanone (4) together with seven known compounds, euchrenone b10 (5), isoerysenegalensein E (6), wighteone (7), laburnetin (8), lupiwighteone (9), erythrodiol (10), and oleanolic acid (11). The structures were determined on the basis of spectroscopic analyses and chemical evidence. The effect of these compounds on the proliferation of rat osteogenic sarcoma (UMR106) is also reported.     

A tetrahydroisoquinoline-monoterpene glucoside and an iridoid glucoside from Alangium kurzii

From the leaves of Alangium kurzii, a new tetrahydroisoquinoline-monoterpene glucoside, 6-O-methyl-N-deacetylipecosidic acid and a new iridoid glucoside, 10-O-benzoyladoxosidic acid, were isolated along with alangiside, demethylalangiside, 6'-O-beta-D-glucosylhenryoside, uridine and four known flavonoid glycosides. The structures of new glucosides were determined on the basis of spectroscopic and chemical methods.     

A New Flavan-3-ol Glucoside from Daphniphyllum oldhami

A new flavan-3-ol glucoside, (-)-afzelechin-7-O-β-D-glucopyranoside (1), has been isolated from the stem of Daphniphyllum oldhami. The structure of the new compound was elucidated on the basis of detailed spectroscopie analysis and comparison with related compounds.     

A new isoflavone from the mangrove endophytic fungus Fusarium sp. (ZZF60)

A new isoflavone, 5-hydroxy-7-methoxy-4'-O-(3-methylbut-2-enyl) isoflavone (1), together with five known compounds, eriodictyol (2), vittarin-B (3), 3,6,7-trihydroxy-1-methoxyxanthone (4), 1,3,6-Trihydroxy-8-methylxanthone (5) and cyclo (Phe-Tyr) (6), was isolated from the mangrove endophytic fungus, Fusarium sp. ZZF60 obtained from the South China Sea. Their structures were determined by the analysis of spectroscopic data.     

Analysis of isoflavones in foods and dietary supplements

Isoflavones are phytochemicals found in many plants. Because of their structural similarity to beta-estradiol, health benefits of isoflavones have been evaluated in age-related and hormone-dependent diseases. Daidzein, genistein, and glycitein are present as free forms or derivatives in foods containing soy or soy protein extracts. The analysis of isoflavones has become more complex, because preparations contain isoflavones from multiple sources (e.g., red clover, kudzu). Red clover contains primarily formononetin and biochanin A, while kudzu extracts, which are becoming increasingly common in dietary supplements, contain puerarin and daidzein, among other components. Isoflavones are present in foods and dietary supplements as free compounds, glucoside derivatives, 6"-O-malonyl-7-O-beta-D-glucoside derivatives, and 6"-O-acetyl-7-O-beta-D-glucoside derivatives. High-performance liquid chromatography (HPLC)/tandem mass spectrometry has been applied to the identification of isoflavone derivatives based on the fragmentation pattern of the parent ion, providing high selectivity and sensitivity in the quantitation of isoflavones in complex mixtures. HPLC with ultraviolet detection is often chosen for routine analysis, but a preliminary acid or basic hydrolysis of isoflavone derivatives is often required for the investigation of samples containing extracts from multiple sources. Several internal standards have been used in the analysis of isoflavones from a single botanical source (e.g., soy, red clover), but the identification of a general internal standard remains a challenging process.     

Iridoid glucosides from Veronica hederifolia

A new iridoid glucoside, urphoside A, and six known iridoid glucosides, pikuroside, aucubin, veronicoside, catalposide, amphicoside, and verminoside, were isolated from Veronica hederifolia together with a known megastigmane glucoside, 3-hydroxy-5,6-epoxy-beta-ionol-9-O-beta-D-glucopyranoside, and a hexitol, dulcitol. The structures of the isolated compounds were established by the extensive 1D- and 2D-NMR spectroscopy.     

New flavone and isoflavone glycoside from Belamcanda chinensis

The new flavone, 5,4'-dihydroxy-6,7-methylenedioxy-3'-methoxyflavone, and one new isoflavone glycoside, 3',5'-dimethoxy irisolone-4'-O-β-D-glucoside were isolated from the rhizomes of Belamcanda chinensis. Their structures were established based on the spectroscopic methods.     

A new angelol-type coumarin glucoside from Angelica pubescens

A new angelol-type coumarin glucoside, 6-[（1R,2R）-1, 2-dihydroxy-3-β-D-glucosyloxy-3-methylbutyl]-7-methoxycoumarin, was isolated from the roots of Angelica pubescens. Its structure was elucidated on the basis of spectral analysis.     

Structure characterization and quantification of a new isoflavone from the arial parts of Phyllanthus niruri

A new isoflavone together with 5,7-dimethoxy-3,4′-dihydroxy-3′,8-di-C-prenylflavanonol and 5,3′-dihydroxy-6,7,4′-trimethoxyflavone has been isolated from the arial parts of Phylanthus niruri. Based on spectral methods, the structure of the new compound was elucidated as 6-hydroxy-7,8,2′,3′,4′-pentamethoxyisoflavone. The isolated isoflavone was quantified by gas chromatography couple with mass spectroscopy (GC–MS) in selected ion monitoring (SIM) mode. Suitable methods for quantification and extraction have been developed. The quantifying limit of this method was less than 5 ng/ml in 10 g (fresh weight) of sample. Recovery of isoflavone in spiked samples exceeded 62–72% while R.S.D. ranged from 1.0% to 6.1%. The results showed significant variation in the amount of this marker in methanol extract of Phylanthus niruri from Kushtia, Bangladesh and Java Island, Indonesia, even though the values were almost identical for most of the cases. Isoflavone was detected in all the samples ranging from 0.12% to 0.29%.     

Iridoid and lignan glycosides from Citharexylum spinosum L

From the aerial parts of Citharexylum spinosum L., one new iridoid glucoside, the 7-ss-O-acetate (1) of lamiide, along with four known iridoid glucosides, lamiide (2), lamiidoside (3), duranterectoside C (4), 8-epiloganin (5) and one known lignan glucoside (+)-lyonirenisol-3a-O-ss-D-glucopyranoside (6) were isolated. The compound structures were established by one- and two-dimensional 1H- and 13C-NMR as well as by ESI-MS spectra.     

Two new isoflavone derivatives from the roots of an Egyptian collection of Lotus polyphyllos

Investigation of the roots of Lotus polyphyllos Clarke resulted in the isolation of two new isoflavone derivatives; 4'-O-methylerythrinin C (3) and 4'-O-methyl-2'-hydroxydihydroalpinumisoflavone (4). In addition, the three known isoflavone derivatives 4'-O-methylalpinumisoflavone (1) lupinalbin F (5), 4',7-dimethoxy-5-hydroxyisoflavone (6), and the phenylpropanoid ester tetracosyl p-coumarate (2) were also identified. The structures were determined from spectroscopic data.