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 2-o-methylrhamno-isoflavones from Streptomyces sp

Chemical screening with extracts of Actinomycetes strains resulted in the detection, isolation and structure elucidation of five new isoflavone glycosides from Streptomyces sp. (GT 51173): 5-O-alpha-L-rhamnopyranosyl genestein (genestein G1, 1), 5-O-alpha-L-rhamnopyranosyl-7-O-[2-O-(methyl)-alpha-L-rhamnopyranosyl] genestein (genestein G2, 2), 7,4'-O-di-[2-O-(methyl)-alpha-L-rhamnopyranosyl] daidzein (daidzein G1, 3), 6-O-methyl-7-O-[2-O-(methyl)-alpha-L-rhamnopyranosyl] daidzein (daidzein G2, 4) and 7-O-[2-O-(methyl)-alpha-L-rhamnopyranosyl] daidzein (daidzein G3, 5). As a striking structural feature, 2-5 bear one or two alpha-L-rhamnopyranosyl sugar moieties with methoxy groups in an axial position at C-2.     

Isoflavone glycosides from the root wood of Erythrina latissima

The molecular structures of 3 isoflavone glycosides isolated from the root wood of Erythrina latissima were established as 4'-hydroxyisoflavone-7-O-beta-D-glucopyranoside (compound 1); 4'-hydroxyisoflavone-7-O-alpha-L-rhamnosyl (1-->6)-beta-D-glucopyranoside (compound 2); and a new compound 4', 8-dimethoxy isoflavone-7-O-alpha-L-rhamnosyl (1-->6) glucopyranoside (8-O-methylretusin-7-O-alpha-L-rhamnosyl (1-6)-beta-D-glucopyranoside) (compound 3).     

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.     

New Isoflavone C‐Glycosides from Pueraria lobata

Three new isoflavone C‐glycosides, along with two known isoflavone O‐glycosides, were isolated from the roots of Pueraria lobata (Willd .) Ohwi . The structures of the new compounds were elucidated as 4′,7‐dihydroxy‐3′‐methoxyisoflavone 8‐C‐[β‐d‐ glucopyranosyl‐(1→6)]‐β‐d‐ glucopyranoside ( 1 ), 4′,7‐dihydroxy‐3′‐methoxyisoflavone 8‐C‐[β‐d‐ apiofuranosyl‐(1→6)]‐β‐d‐ glucopyranoside ( 2 ), and 8‐C‐β‐d‐ glucopyranosyl‐4′,7‐dihydroxy‐3′‐methoxyisoflavone 4′‐O‐β‐d‐ glucopyranoside ( 3 ) on the basis of spectroscopic methods, especially 2D‐NMR and MS analyses. The known compounds isolated were identified by comparison of their physical and spectroscopic data with those reported in the literature.     

Triterpene glycosides from the sea cucumber Eupentacta fraudatrix. Structure and biological action of cucumariosides A1, A3, A4, A5, A6, A12 and A15, seven new minor non-sulfated tetraosides and unprecedented 25-keto, 27-norholostane aglycone

Seven new minor triterpene glycosides, cucumariosides A1 (1), A3 (2), A4 (3), A5 (4), A6 (5), A12 (6) and A15 (7) have been isolated from the Far Eastern sea cucumber Eupentacta fraudatrix. Structures of the glycosides were elucidated by 2D NMR spectroscopy and MS. Glycosides 1-7 belong to the group of cucumariosides A, having linear tetrasaccharide carbohydrate moieties without any sulfate group and possessing 3-O-methyl-D-xylose as a terminal monosaccharide unit. The latter peculiarity is rare in sea cucumber glycosides, but typical for the glycosides from E. fraudatrix. Glycosides 1-7 differ from each other by side chain structures in the aglycone moieties; three of them have unique structural features. The first is the presence of a 25-butoxy-group in the side chain of cucumarioside A3 (2), the second is a 23E,25-diene system in cucumarioside A6 (5) and the third is a 25-keto-27-nor-holostane aglycone in cucumarioside A12 (6); these were never previously found in sea cucumber glycosides. Cytotoxic activity of glycosides 1-7 against mouse spleen lymphocytes and the cells of the ascite form of mouse Ehrlich carcinoma, along with hemolytic activity against mouse erythrocytes and antifungal activity were studied. Glycosides 1 and 5 were the most active in all the tests.     

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.     

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.     

Alpha-glucosidase inhibitors from Millettia conraui

A new geranylated isoflavone, 7-O-geranyl-6-methoxypseudobaptigenin (1) was isolated from the stem barks of Millettia conraui, along with known compounds 5-methoxydurmillone (2), conrauinone A (3), beta-amyrine (4), sitosterol (5), 3-O-beta-D-glucopyranosyl sitosterol (6) and n-docosanol (7). Compounds 1 and 4 showed a significant alpha-glucosidase inhibitory activity. The structures of the compounds were determined by analysis of their spectroscopic data.     

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.     

Medicinal foodstuffs. XVIII. Phytoestrogens from the aerial part of Petroselinum crispum MIll. (Parsley) and structures of 6"-acetylapiin and a new monoterpene glycoside, petroside

In the course of our screening for natural estrogenic compounds from Occidental medicinal herbs, the extracts of several herbs were found to show proliferative activity in MCF-7 (an estrogen-sensitive breast cancer cell line). Among these active herbs, the methanolic extract from the aerial parts of Petroselinum crispum (parsley) showed potent estrogenic activity, which was equal to that of isoflavone glycosides from soybean. Through bioassay-guided separation, we isolated several flavone glycosides and a new flavone glycoside, 6"-acetylapiin, with estrogenic activity together with a new monoterpene glucoside, petroside. The structures of 6"-acetylapiin and petroside were characterized by the chemical and physicochemical evidence. Estrogenic activities of these flavone glycosides were found to be enhanced by removal of their glycoside moieties. The EC50 values (concentration needed to enhance the MCF-7 proliferation 50% compared to non-estrogen treated cell) of their aglycones are as follows, apigenin (1.0 microM), diosmetin (2.9 microM), and kaempferol (0.56 microM). The estrogenic activities of these flavones are nearly equal to those of the isoflavones, daidzein (0.61 microM) and genistein (0.60 microM). The methanolic extract of parsley, apiin, and apigenin restored the uterus weight in ovariectomized mice when orally administered for consecutive 7 days.     

Triterpene glycosides from the sea cucumber Eupentacta fraudatrix. Structure and cytotoxic action of cucumariosides A2, A7, A9, A10, an, A13 and A14, seven new minor non-sulfated tetraosides and an aglycone with an uncommon 18-hydroxy group

Seven new minor triterpene glycosides, cucumariosides A2 (1), A7 (2), A9 (3), A10 (4), A11 (5), A13 (6) and A14 (7) have been isolated from the Far Eastern sea cucumber Eupentacta fraudatrix. Structures of the glycosides were elucidated by 2D NMR spectroscopy and MS. Glycosides 1-7 belong to the group of cucumariosides A, having linear tetrasaccharide carbohydrate moieties without any sulfate group and possessing 3-O-methyl-D-xylose as a terminal monosaccharide unit. Glycosides 1, 2, 5-7 differ from each other in side chain structures in aglycone moieties, while cucumarioside A10 (4) has a 23,24,25,26,27-pentanorlanostane aglycone with 18(16)-lactone. Cucumarioside A9 (3), having an uncommon 18-hydroxy group, is the second representative of the unique metabolically active glycosides that are regarded as intermediates of glycoside biosynthesis in sea cucumbers. Cytotoxic activities of glycosides 1-7 and cucumarioside A8 (8) against mouse spleen lymphocytes and the cells of the ascite form of mouse Ehrlich carcinoma, along with hemolytic activity against mouse erythrocytes and antifungal activity were studied. Cucumariosides A2 (1), A8 (8) and A13 (6) demonstrated high hemolytic activities. Glycosides 1, 4 and 6 showed moderate cytotoxic activity. Only cucumarioside A8 (8), having an 18-oxymethylene group and a 24(25)-double bond, was very active in all the tests.     

Cucurbitane glycosides from unripe fruits of Lo Han Kuo (Siraitia grosvenori)

From the unripe fruits of Lo Han Kuo (Siraitia grosvenori), a Chinese medicinal plant, two new cucurbitane triterpene glycosides, 20-hydroxy-11-oxomogroside IA(1) (1) and 11-oxomogroside IIE (2), were isolated along with five known cucurbitane glycosides, 11-oxomogroside IA(1) (3), mogroside IIE (4), mogroside III (5), mogroside IVA (6), and mogroside V (7), and two flavonoid glycosides, kaempferol 7-O-alpha-L-rhamnopyranoside (8) and kaempferol 3,7-di-O-alpha-L-rhamnopyranoside (9). Their structures were determined on the basis of detailed analyses of 1D, 2D-NMR spectroscopic methods and by comparing with literature values. This paper describes the first investigation of unripe bitter Lo Han Kuo fruits.     

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.     

Selective separation of flavonoid glycosides in Dalbergia odorifera by matrix solid-phase dispersion using titania

Dalbergia odorifera contains high concentrations of flavonoid aglycones and trace flavonoid glycosides. In this study, trace flavonoid glycosides were separated from D. odorifera by titania with matrix solid-phase dispersion (MSPD). Before the MSPD experiment, four standards, including two isoflavone glycosides (genistin and formononetin-8-C-apiosyl (1-6)-glucoside) and their aglycones (genistein and formononetin), were used to compare their retention on a titania column. The effect of acetonitrile concentration and pH on their retention was investigated and a conclusion was drawn that high acetonitrile concentration and pH lead to the greatest difference in the retention of flavonoid as glycosides and aglycones. Besides hydrophilic interaction and ligand-exchange interaction may exist between sugar moiety of flavonoid glycoside and titania, so that flavonoid glycosides have stronger retention than that of aglycones. Based on the chromatographic rule of flavonoid as glycosides and aglycones on the titania column, the MSPD method was optimized to elute high concentration flavonoid aglycones first with 90% acetonitrile and 10% water containing 100 mM ammonium acetate buffer, and then to elute trace flavonoid glycosides with 20% acetonitrile and 80% water containing 1% trifluoroacetate (TFA). Isolated flavonoid glycosides were further analyzed by UPLC-MS/MS, and their fragmentation in MS(2) showed they are C-glycosyl flavonoids.     

Phytochemical Screening on Mussaenda Philipica Sepals — Isolation of Iridoid Glycosides and Flavones

JPC – Journal of Planar Chromatography – Modern TLC - Three iridoid glycosides, 5-hydroxy davisioside (1), 4-acetoxy-7-methoxy secologanin (4) and 6-methoxy mussaenoside (5) as well as...     

Compositions of royal jelly II. Organic acid glycosides and sterols of the royal jelly of honeybees (Apis mellifera)

Two organic acid glycosides (1, 2) and 16 sterols were isolated from the royal jelly of honeybees (Apis mellifera). The former two were monoglucosides of 10-hydroxy-2E-decenoic and 10-hydroxydecanoic acids. They are the first examples of glycosides isolated from royal jelly. The latter 16 were sterols mainly composed of 28 or 29 carbons. Among them, four compounds were new isofucosterol derivatives, and their structures were characterized as (24Z)-stigmasta-5,24(28)-dien-3beta-ol-7-one (3), (24Z)-stigmasta-5,24(28)-diene-3beta,7beta-diol (4), (24Z)-stigmasta-5,24(28)-diene-3beta,7alpha-diol (5), and (24Z)-stigmast-24(28)-ene-3beta,5alpha,6beta-triol (6) on the basis of various NMR spectroscopic data.     

Chemical constituents from the leaves of Manglietia phuthoensis and their effects on osteoblastic MC3T3-E1 cells

Two new phenyl glycosides, mangliesides A and B (1, 2), a new ionol glycoside, manglieside C (3), two new lignan glycosides, mangliesides D and E (4, 5), were isolated from the leaves of Manglietia phuthoensis, along with two known lignans, 3-methoxymagnolol (6) and obovatol (7). Their structures were established by means of 1D and 2D NMR, electrospray ionization (ESI)-MS and HR-ESI-MS experiments. Among them, compounds 2 and 5 significantly (p<0.05) increased the growth and differentiation of osteoblastic MC3T3-E1 cells in vitro.     

细枝岩黄芪根部中的三个新的异戊烯基呋喃异黄酮

岩黄芪属植物中的多序岩黄芪作为传统中药“红芪”有着广泛的药用价值,而同属的红花岩黄芪也报道具有良好的药用活性。我们对该属中的细枝岩黄芪根部的化学成份进行了研究,从中分离得到了三个新的异戊烯基呋喃异黄酮,分别为：5-羟基-7-(2-羟基异丙基)-4′-甲氧基-9-苯并呋喃[3,2-g]异黄酮(1),5-羟基-4′-甲氧基-9-苯并呋喃[3,2-g]异黄酮(2),5-羟基-7-(2-羟基异丙基)-4′-甲氧基-7-苯并呋喃[2,3-h]异黄酮(3),并对这三个新化合物的清除自由基能力进行了测试。     

Rossicasins A, B and rosicaside F, three new phenylpropanoid glycosides from Boschniakia rossica

Three phenylpropanoid glycosides have been isolated, together with the known phenylpropanoid glycosides rossicaside A (4), B (5), E (6), and trans-p-coumaryl alcohol 1-O-beta-D-glucopyranosyl(1-->4)-alpha-L-rhamnopyranosyl(1-->3)-beta-D-glucopyranoside (7), and an acylated oligosaccharide beta-D-glucopyranosyl(1-->4)-alpha-L-rhamnopyranosyl-(1-->3)-(4-O-trans-caffeoyl)-D-glucopyranose) (8), from the aqueous extract of Boschniakia rossica (CHAM. et SCHLECH.) FEDTSCH. et FLEROV. Spectroscopic evidence led to the assignments of their structures as trans-p-coumaryl-(6'-O-beta-D-xylopyranosyl)-O-beta-D-glucopyranoside (1), trans-p-coumaryl-(6'-O-alpha-L-arabinopyranosyl)-O-beta-D-glucopyranoside (2) and 2-(3,4-dihydroxyphenyl)-R,S-2-ethoxy-ethyl-O-beta-D-glucopyranosyl(1-->4)-alpha-L-rhamnopyranosyl(1-->3)(4-O-trans-caffeoyl)-beta-D-glucopyranoside (3), designated as rossicasin A, rossicasin B, and rossicaside F, respectively. Compound 7 was identified from the degradation reaction and this is the first isolation from a natural source.