Steroidal glycosides from the roots of Asclepias curassavica

Twenty-six new acylated-oxypregnane glycosides were obtained along with three known cardenolide glycosides from the roots of Asclepias curassavica (Asclepiadaceae). The new compounds were confirmed to contain 12-O-benzoylsarcostin, 12-O-benzoyldeacylmetaplexigenin, kidjolanin, and 12-O-benzoyltayloron, and one new acylated-oxypregnane, 12-O-(E)-cinnamoyltayloron, as their aglycones, using both spectroscopic and chemical methods.     

Larrealignans A and B, novel lignan glycosides from the aerial parts of Larrea tridentata

Two new lignan glycosides, named larrealignans A (1) and B (2), and a known lignan (3) were isolated from the aerial parts of Larrea tridentata (Zygophyllaceae). The structures of 1 and 2 were determined on the basis of spectroscopic analysis and the results of hydrolytic cleavage. The isolated compounds (1-3) and aglycones (1a, 2a) of 1 and 2 were evaluated for their cytotoxic activities against HL-60 human leukemia cells.     

New azomethine cardenolide glycosides

New azomethines (aldimines) were synthesized from cardiac glycosides erysimin and cymarin. The structures of the new compounds were confirmed by PMR spectra and elemental analysis. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 362–363, July–August, 2006.     

Steroidal glycosides from the aerial part of Asclepias incarnata L. II

Thirty new steroidal glycosides were obtained from the aerial part of Asclepias incarnata L. (Asclepiadaceae). These glycosides were confirmed to have lineolon, isolineolon, 12-O-acetyllineolon, 12-O-(Z)-cinnamoyllineolon, metaplexigenin, 15 beta-hydroxylineolon, 15 beta-hydroxyisolineolon, 16 alpha-hydroxyisolineolon, 12-O-tigloyl-16 alpha-hydroxyisolineolon as the aglycone and 2,6-dideoxyhexopyranose as the sugar sequence by spectroscopic methods and chemical evidence.     

An androstane bioside and 3'-thiazolidinone derivatives of doubly-linked cardenolide glycosides from the roots of Asclepias tuberosa

Steroidal compounds in the roots of Asclepias tuberosa were investigated and 17alpha-hydroxyandrosta-4,6,15-trien-3-one 17-O-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranoside, termed ascandroside, was isolated from the CHCl3-soluble fraction. Among five doubly-linked cardenolide glycosides, two were identified as 3'-spiro-linked thiazolidinone (4) and S-oxythiazolidinone derivatives (5) of delta5-calotropin. The stereochemistry at the C-3' in these two cardenolides is discussed. 3'-O-beta-D-Glucopyranosyl-delta5-calotropin (3) was also isolated along with A5-calotropin and its 3'-acetate. Nine glycosides of uzarigenin, coroglaucigenin and corotoxigenin were identified.     

New lignan glycosides from Glehnia littoralis

From the roots ethanol extract of Glehnia littoralis, two new lignan glycosides, named glehlinoside E (1) and F (2), were obtained. Their structures were determined to be (-)-secoisolariciresinol 4-O-β-D-(6-O-feruloyl) glucopyranoside (1) and (-)-secoisolariciresinol 4-O-β-D-(6-O-caffeloyl) glucopyranoside (2) by analysis of their spectral data, respectively.     

New lignan glycosides from Cissus quadrangularis stems

Phytochemical investigation of Cissus quadrangularis stems led to the isolation of one new phenolic glycoside (1) and two new lignan glycosides (7 &; 8) along with twelve known compounds (2–6 &; 9–15). Their chemical structures were determined on the basis of extensive spectroscopic analysis using 1D, 2D NMR, and mass spectrometric analysis. Among the known compounds, 4–6, 9 and 12 were isolated for the first time from the genus Cissus whereas compounds 10, 11 and 13 for the first time from this plant.     

New cytotoxic lignan glycosides from Phyllanthus glaucus

During the process of exploring bioactive lead compounds from Phyllanthus species, two new glycosides including an arylnaphthalene lignan, diphyllin 4-O-α-l-arabinopyranosyl-(1 → 3)-α-l-arabinopyranoside (1), and a phenolic compound, 3,4,5-trimethoxybenzyl alcohol 7-O-α-l-arabinofuranosyl-(1 → 6)-β-d-glucopyranoside (2), were isolated from the methanol extract of the whole plants of Phyllanthus glaucus Wall. ex Müll. Arg. In addition, 31 known compounds, including 19 lignan derivatives (3–21), four phenylpropanoids (22–25), seven simple phenolics (26–32) and one monoterpenoid (33) were obtained. Their structures were determined on the basis of the HR-ESI-MS, 1D and 2D NMR spectroscopic analysis, and pre-column derivative/chiral HPLC analysis in case of 1 for the absolute configurations. All these compounds were obtained from P. glaucus for the first time. Moreover, the known lignan glycoside, phyllanthusmin C (5) showed in vitro cytotoxicities against HL-60, MCF-7 and SW480 cells with IC₅₀ values of 9.2 ± 0.2, 19.2 ± 1.7 and 20.5 ± 0.9, respectively.     

Two new acylated iridoid glucosides from the aerial parts of Paederia scandens

Two new acylated iridoid glucosides were isolated from the aerial parts of Paederia scandens along with six known iridoid glucosides. The structures of two new compounds were elucidated as 6'-O-E-feruloylmonotropein (1) and 10-O-E-feruloylmonotropein (2) by spectroscopic methods.     

A new lignan glycoside from the aerial parts and cytotoxic investigation of Uvaria rufa

Chemical investigation of the aerial parts of Uvaria rufa (Dunal) Blume collected from Vietnam yielded one new lignan glycoside, ufaside (1), along with six known compounds, oxoanolobine (2), ergosta-4,6,8(14),22-tetraen-3-one (3), catechin (4), epicatechin (5), daucosterol (6) and glutin-5-en-3-one (7). Their chemical structures were determined by using NMR, HR-MS spectroscopic analyses and in comparison with the reported data. A cytotoxic analysis of U. rufa herb extracts was performed for the first time using nine human cancer cell lines (MCF-7, MDA-MB-231, LNCaP, MKN7, SW480, KB, LU-1, HepG2 and HL-60) derived from different tumour types. Of these seven constituents, compounds 2 and 3 displayed moderate cytotoxicity against the human lung adenocarcinoma cell line (LU-1) with IC₅₀ values of 9.22 ± 1.02 μg/mL and 10.21 ± 1.16 μg/mL, respectively.     

Two new phenolic glycosides from the aerial parts of Androsace umbellata

Two new phenolic glycosides,2-hydroxy-4-O-β-D-glucopyranosylphenylacetic acid methyl acetate(1) and 2-hydroxy-4-O-β-D-glucopyranosylphenylacetic acid(2) were isolated from the aerial parts of Andwsace umbellata.Their structures were elucidated by spectral techniques.     

Three new flavonol glycosides from the aerial parts of Rodgersia podophylla

Three new flavonol glycosides were isolated together with five known flavonoids and six bergenin derivatives from the aerial parts of Rodgersia podophylla. The structures of these new compounds were elucidated by spectral methods as kaempferol-3-O-alpha-L-5'-acetyl-arabinofuranoside (1), kaempferol 3-O-alpha-L-3'-acetyl-arabinofuranoside (2), and quercetin-3-O-alpha-L-3',5'-diacetyl-arabinofuranoside (3).     

New lignan glycosides from Glehnia littoralis

From the roots ethanol extract of Glehnia littoralis, two new lignan glycosides, named glehlinoside E （1） and F （2）, were obtained. Their structures were determined to be （-）-secoisolariciresinol 4-O-β-D-（6-O-feruloyl） glucopyranoside （1） and （-）- secoisolariciresinol 4-O-f-β-D-（6-O-caffeloyl） glucopyranoside （2） by analysis of their spectral data, respectively.     

New Structures,Spectrometric Quantification,and Inhibitory Properties of Cardenolides from Asclepias curassavica Seeds

Cardiac glycosides are a large class of secondary metabolites found in plants. In the genus Asclepias, cardenolides in milkweed plants have an established role in plant–herbivore and predator–prey interactions, based on their ability to inhibit the membrane-bound Na⁺/K⁺-ATPase enzyme. Milkweed seeds are eaten by specialist lygaeid bugs, which are the most cardenolide-tolerant insects known. These insects likely impose natural selection for the repeated derivatisation of cardenolides. A first step in investigating this hypothesis is to conduct a phytochemical profiling of the cardenolides in the seeds. Here, we report the concentrations of 10 purified cardenolides from the seeds of Asclepias curassavica. We report the structures of new compounds: 3-O-β-allopyranosyl coroglaucigenin (1), 3-[4′-O-β-glucopyranosyl-β-allopyranosyl] coroglaucigenin (2), 3′-O-β-glucopyranosyl-15-β-hydroxycalotropin (3), and 3-O-β-glucopyranosyl-12-β-hydroxyl coroglaucigenin (4), as well as six previously reported cardenolides (5–10). We test the in vitro inhibition of these compounds on the sensitive porcine Na⁺/K⁺-ATPase. The least inhibitory compound was also the most abundant in the seeds—4′-O-β-glucopyranosyl frugoside (5). Gofruside (9) was the most inhibitory. We found no direct correlation between the number of glycosides/sugar moieties in a cardenolide and its inhibitory effect. Our results enhance the literature on cardenolide diversity and concentration among tissues eaten by insects and provide an opportunity to uncover potential evolutionary relationships between tissue-specific defense expression and insect adaptations in plant–herbivore interactions.     

Three new acyclic diterpene glycosides from the aerial parts of paprika and pimiento

Paprika and pimiento are used as vegetables and spices. We have obtained three new acyclic diterpene glycosides, called capsianosides XVII (1), V methyl ester (2) and XIV (3) together with capsianosides I and II from the aerial parts of paprika and pimiento. The structures of these compounds have been established by (1)H- and (13)C-NMR spectra and two-dimensional NMR methods.     

Pregnane glycosides from the roots of Asclepias tuberosa

Sixteen glycosides of pregnanes, including ikemagenin, lineolon, and a new pregnane, 3beta8beta,14beta,15beta,16alpha-pentahydroxy-++ +5alpha-pregnan-20-one, termed pleurogenin, were isolated from the roots of Asclepias tuberosa. Among ikemagenin and lineolon glycosides, one (1) was a known glycoside, and eight (2-7, 10, 13) were glycosides with new combinations of ikemagenin or lineolon and known sugar sequences composed of D-cymarose, D-oleandrose, D-thevetose and D-glucose. The structures of four new glycosides of ikemagenin (8, 9, 11, 12) and three of pleurogenin (14-16) were determined. The new glycosides have sugar sequences ranging from tetraoside to heptaosides.     

8-O-4’ Neolignan glycosides from the aerial parts of Matteuccia struthiopteris

Two new 8-O-4’ neolignan glycosides, named matteustruthiosides A(1) and B(2) were isolated from the aerial parts of Matteuccia struthiopteris. Their chemical structures were characterized on the basis of various spectroscopic techniques. The absolute configurations of them were determined by experimental circular dichroism(CD) spectra. Compounds 1 and 2 were inactive against influenza A(H1N1) virus in vitro.     

New lignan glycosides from Chinese medicinal plant,Sinopodophillum emodi

Two new podophillotoxin glucosides, L-picropodophillotpxin 7'-O-(beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside) (2) and L-picropodophillotpxin 7'-O-beta-D-glucopyranoside (3), were isolated from Chinese medicinal plant, Sinopodophillum emodi, together with 4 known compounds, podophillotoxin (1), podorhizol 4'-O-beta-D-glucopyranoside (4), deoxypodophillotoxin (5), and dehydropodophillotoxin (6). The structures of 2 and 3 were finally determined by the extensive decouping and nuclear Overhauser effect (NOE) experiments in NMR spectra and circular dichroism (CD) spectra. Compound 2 is the second example of podophillotoxin diglucoside, and both the first one and 2 were isolated from S. emodi. X-ray crystal structure analysis of 1, 5, and 6 was carried out. Compounds 1 and 5 showed the different conformations from those reported.     

Trojanosides I-K: new cycloartane-type glycosides from the aerial parts of Astragalus trojanus.

Three new cycloartane-type triterpene glycosides have been isolated from the aerial parts of Astragalus trojanus. The structures were established mainly by a combination of one- and two-dimensional NMR techniques [1H-1H-correlation spectroscopy (COSY), 1H-13C-heteronuclear multiple quantum correlation spectroscopy (HMQC), and 1H-13C-heteronuclear multiple-bond correlation spectroscopy (HMBC)] and high resolution electrospray ionization mass spectrometry (HR-ESI-MS) as 3-O-beta-(2',3'-di-O-acetyl)-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-16-O- acetoxy-20(R),24(S)-epoxycycloartane-3beta,6alpha,16beta,25-tetrol, 3-0-[alpha-L-rhamnopyranosyl-(1-->2)-beta-(3',4'-di-O-acetyl)-D-xylopyranosyll-6-O-beta-D-xylopyranosyl-20(R),24(S)-epoxycycloartane-3p,6alpha,16beta,25-tetrol, 3-O-beta-D-xylopyranosyl-6,16-di-O-beta-D-glucopyranosyl-20(R)24(S)-epoxycycloartane-3beta,6alpha,16beta,25-tetrol.