Isolation from a softwood xylan of oligosaccharides containing two 4-O-methyl-d-glucuronic acid residues

Partial hydrolysis of a larch arabino(4-O-methylglucurono)xylan afforded two series of oligouronides composed of 4-O-methyl- d-glucuronic acid and d-xylose residues. The first series included aldouronic acids up to the aldopentaouronic acid. Methylation analysis indicated that the aldopentao- and aldotetrao-uronic acids were mixtures of isomers. One aldotetraouronic acid was isolated and identified as O-β-d-Xylp-(1 → 4)-O-β-d-Xylp-(1 → 4)-O-(4-O-Me-α-d-GlcAp)-(1 → 2)-d-Xyl. The two isomeric aldotriouronic acids were separated from each other. The acids of the second series, which were composed of two uronic acids and 2-4 d-xylose residues, were identified as follows: O-β-d-Xylp-(1 → 4)-O-(4-O-Me-α-d-GlcAp)-(1 → 2)-O-β-d-Xylp-(1 → 4)-O(4-O-Me-α-d-GlcAp)-(1 → 2)-O-β-d-Xylp-(1 → 4)-d-Xyl, O-(4-O-Me-α-d-GlcAp)-(1 → 2)-O-β-d-Xylp-(1 → 4)-O-(4-O-Me-α-d-GlcAp)-(1 → 2)-O-β-d-Xylp-(1 → 4)-O-β-d -Xylp-(1 → 4)-D-Xyl, O-(4-O-Me-α-d-GlcAp)-(1 → 2)-O-β-d-Xylp-(1 → 4)-O-(4-O-Mec-α-d-GlcAp)-(1 → 2)-O-β-d-Xylp-(1 → 4)-D-Xyl, and O-(4-O-Me-α-d-GlcAp)-(1 → 2)-O-β-d-Xylp-(1 → 4)-O-(4-O-Me-α-d-GlcAp)-(1 → 2)-D-Xyl. The first three compounds were new acidic oligosaccharides. The 4-O-methyl-d-glucuronic acid in the second series was present in a larger proportion than in the first series, indicating that a large proportion of the uronic acid side-chains were located on two contiguous D-xylose residues in the backbone of the softwood xylan.     

Spirostanol saponins from Paris polyphylla,structures of polyphyllin C,D, E and F

The structures of four new saponins, polyphyllin C, D, E and F, isolated from the tubers of Paris polyphylla have been elucidated as diosgenin-3-O-α-l-rhamnopyranosyl(1→3)-β-d-glucopyranoside, diosgenin-3-O-α-l-rhamnopyranosyl(1→3)- [α-l-arabinofuranosyl(1→4)]-β-d-glucopyranoside, diosgenin-3-O-α-l-rhamnopyranosyl(1→2)-α-l-rhamnopyranosyl (1→4)[α-l-rhamnopyranosyl(1→3)]-β-d-glucopyranoside and diosgenin-3-O-α-l-rhamnopyranosyl(1→4)[α-l- rhamnopyranosyl(1→3)][β-d-glucopyranosyl(1→2)]-α-l-rhamnopyranoside, respectively, on the basis of chemical and spectral data.     

Structures of 3,28-O-bisglycosidic triterpenoid saponins of Fatsia japonica

Four novel 3,28-O-bisglycosidic triterpenoid saponins were isolated from the mature fruits of F. japonica. They were characterized as the 28-O-α-l-rhamnopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-β- d-glucopyranosides of 3-O-α-l-arabinopyranosyl echinocystic acid, 3-O-α-l-arabinopyranosyl hederagenin, 3-O-β-d-glucopyranosyl-(1 → 2)-α-l-arabinopyranosyl oleanolic acid and 3-O-β- d-glucopyranosyl-(1 → 2)-α-l-arabinopyranosyl hederagenin respectively.     

Structural studies on some saponins from Lecaniodiscus cupanioides

Four triterpenoid saponins isolated from the stem bark of Lecaniodiscus cupanioides and denoted S-2,S-3,S-4 and S-5, were identified as follows. S-2:3-O-[α-l-arabinopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyl]-hederagenin; S-3:3-O-[α-d-xylopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-l-arabino-pyranosyl ]-hederagenin; S-4:3-O- [α-l-arabinopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→ 2)-α-l-arabinopyranosyl]-hederagenin; S-5:3-O- [α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyl ]-hederagenin. Of these, S-2 and S-4 are new substances.     

Steroidal saponins of Asparagus curillus

Three spirostanol and two furostanol glycosides were isolated from a methanol extract of the roots of Asparagus curillus and characterized as 3-O-[α-l-arabinopyranosyl (1→4)- β-d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, 3-O-[{α-l-rhamnopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β-d-glucopyranosyl]-(25S)-5β-spirostan- 3β-ol, 3-O-[{β-d-glucopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β- d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, 3-O-[{β-d-glucopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]- 22α-methoxy-(25S)-5β-furostan-3β, 26-diol and 3-O-[{β-d-glucopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]- (25S)-5β-furostan-3β, 22α, 26-triol respectively.     

18-Norspirostanol derivatives from Trillium tschonoskii

Three 18-norspironstanol oligoglycosides partly acylated in their sugar moieties were isolated from the underground parts of Trillium tschonoskii. Their structures were characterized, as 1-O-[2″,3″,4″-tri-O-acetyl-α-l-rhamnopyranosyl-(1 → 2)-α-l-arabinopyranosyl]-epitrillenogenin-24-O-acetate, 1-O-[2″,3″,4″-tri-O-acetyl-α-l-rhamno-pyranosyl-(1 → 2)-α-l-arabinopyranosyl]-epitrillenogenin and 1-O-[2″,4″-di-O-acetyl-α-l-rhamnopyranosyl-(1 → 2)-α-l-arabinopyranosyl]-epitrillenogenin-24-O-acetate.     

New trans- and cis-p-coumaroyl flavonol tetraglycosides from the leaves of Mitragyna rotundifolia

Two new flavonol tetraglycosides, quercetin 3-O-(4-O-trans-p-coumaroyl)-α-l-rhamnopyranosyl (1→2) [α-l-rhamnopyranosyl (1→6)]-β-d-glucopyranoside-7-O-α-l-rhamnopyranoside (krathummuoside A) and quercetin 3-O-(4-O-cis-p-coumaroyl)-α-l-rhamnopyranosyl (1→2) [α-l-rhamnopyranosyl (1→6)]-β-d-glucopyranoside-7-O-α-l-rhamnopyranoside (krathummuoside B) were isolated from the leaves of Mitragyna rotundifolia in addition to eight known compounds, quercetin 3-O-α-l-rhamnopuranosyl (1→2) [α-l-rhamnopyranosyl (1→6)]-β-d-glucopyranoside-7-O-α-l-rhamnopyranoside, rutin, (−)-epi-catechin, 3,4,5-trimethoxyphenyl β-d-glucopyranoside, (6S, 9R)-roseoside, 3-O-β-d-glucopyranosyl quinovic acid 28-O-β-d-glucopyranosyl ester, (+)-lyoniresinol 3α-O-β-d-glucopyranoside, and (+)-syringaresinol-4-O-β-d-glucopyranoside. The structure elucidation of these compounds was based on analyses of spectroscopic data including 1D- and 2D-NMR.     

New steroidal saponins of Agave americana

Two new saponins, agavasaponin E and agavasaponin H have been isolated from the methanolic extract of Agave americana leaves and their structures elucidated. Agavasaponin E is 3-O-[β-d-xylopyranosyl-(1→2glc1)-α-l-rhamnopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→3glc 1)-β-d-glucopyranosyl-(1→4)-β-d-glucopyranosyl-(1→4)-α-d-galactopyranosyl]-(25R)-5α-spirostan-12-on-3β-ol, whereas agavasaponin H is 3-O-[β-d-xylopyranosyl-(1→2 glc 1)-α-l-rhamnopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→3 glc 1)-β-d-glucopyranosyl-(1→4)-β-d-glucopyranosyl-(1→4)-β-d-galactopyranosyl]-26-O-[β-d-glucopyranosyl]-(25R)-5α-furostan-12-on-3β,22α,26-triol.     

Oleanane-type glycosides from Weigela x Styriaca and two cultivars of W. florida: “Minor black” and “Brigela”

Sixteen oleanane-type glycosides were extracted from three Weigela hybrids and cultivars: W. x Styriaca, W. florida “Minor black” and W. florida “Brigela”, and four of them were previously undescribed ones: 3-O-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyloleanolic acid, 3-O-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid, 3-O-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid, and 3-O-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid. Their full structural elucidation required extensive 1D and 2D NMR experiments, as well as mass spectrometry analysis. Six compounds among the known ones were in sufficient amount to be tested for their antifungal activity against Candida albicans, and their antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa.     

Rhamnazin- und rhamnetin-3-O-trioside aus Rhamnus petiolaris

From the fruits of Rhamnus petiolaris two new flavonol-3-O-triosides were isolated and identified as rhamnazin-3-O-[α-l-rhamnopyranosyl (1 → 4)-α-l-rhamnopyranosyl (1 → 6)]-β-d-galactopyranoside and rhamnetin-3-O-α-l-rhamnopyranosyl (1 → 2)-α-l-rhamnopyranosyl (1 → 6)]-β-d-galactopyranoside, respectively.     

Beshornin and beshornoside,steroidal saponins of Beshorneria yuccoides

Two new saponins beshornin and beshornoside have been isolated from the methanolic extract of Beshorneria yuccoides leaves and their structures elucidated. Beshornin is 3-O-[α-l-rhamnopyranosyl-(1 → 4)-β-d-glucopyranosyl- (1 → 2)-[α-l-rhamnopyranosyl-(1 -+ 4)-P-D-glucopyranosyl-(1 → 3)]-β-d-glucopyranosyl-(1 → 4)-β-d- galactopyranosyl-(25R)-5α-spirostan-3β-ol, whereas beshornoside is 3-O-[α-l-rhamnopyranosyl-(1 → 4)- β-d)-glycopyranosyl-(1 → 2)]-[α-l-rhamnopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 3)]-β-d-glucopyranosyl- (1 → 4)-β-d-galactopyranosyl 26-O-[β-d]-glucopyranosyl-(25R)-5α-furostan-3β,22α,26-triol.     

Oligofuro- and spiro-stanosides of Asparagus adscendens

Two oligofurostanosides and two spirostanosides, isolated from a methanol extract of Asparagus adscendens (leaves), were characterized as 3-O-[{α-l-rhamnopyranosyl (1 → 4)} {α-l-rhamnopyranosyl (1 → 6)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]-22α-methoxy-(25S)-furost-5-en-3β,26-diol (Adscendoside A), 3-O-[{α-l-rhamnopyranosyl (1 → 4)} {α-l-rhamnopyranosyl (1 → 6)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]-(25S)-furost-5-en-3β,22α,26-triol-(Adscendoside B), 3-O-[{α-l-rhamnopyranosyl (1 → 6)}-β-d-glucopyranosyl]-(25S)-spirostan-5-en-3β-ol (Adscendin A) and 3-O-[{α-l-rhamnopyranosyl (1 → 4)} {α-l-rhamnopyranosyl (1 → 6)}-β-d-glucopyr anosyl]-(25S)-spirostan-5-en-3β-ol (Adscendin B), respectively. Adscendin B and Adscendoside A are the artefacts of Adscendoside B formed through hydrolysis and methanol extraction respectively.bl]     

Three phenylpropanoid glycosides from Mussatia

Three new phenylpropanoid glycosides, mussatioside I, mussatioside II and mussatioside III were isolated from the methanolic extract of the bark of a new Mussatia species. On the basis of the chemical and spectral evidence their structures were determined as [β-(4′-hydroxyphenyl)ethyl-O-β-D-glucopyranosyl(6 → 1)]-O-β-D-xylopyranosyl(1 → 3)-α-L-(4-O-t-cinnamoyl)rhamnopyranoside, [β-(4′-hydroxyphenyl)-ethyl-O-β-D-glucopyranosyl(6 → 1)]-O-β-D-xylopyranosyl(1 → 3)-α-L-(4-O-dimethylcaffeoyl)rhamnopyranoside and [β-(4′-hydroxyphenyl)ethyl-O-β-D-glucopyranosyl(6 → 1)]-O-β-D-xylopyranosyl(1 → 3)-α-L-(4-O-p-methylcoumaroyl)rhamnopyranoside, respectively. M. hyacinthina was also found to contain mussatioside I.     

Molecular complexation of α-hederin with hederasaponin C

The molecular complexation of triterpene glycosides α-hederin (hederagenin 3-O-α-L-rhamnopyranosyl-(1 → 2)-O-α-L-arabinopyranoside) with hederasaponin C (hederagenin 3-O-α-L-rhamnopyranosyl-(1 → 2)-O-α-L-arabinopyranosyl-28-O-α-L-rhamnopyranosyl-(1 → 4)-O-β-D-glucopyranosyl-(1 → 6)-O-β-D-glucopyranoside) was investigated for the first time using the methods of IR- and electrospray ionization mass spectroscopy. The glycosides form a complex in the 1: 1 molar ratio. The influence of complex on Avena sativa seeds germination and its ichthyotoxicity against Poecilia reticulata were studied.     

Molecular complexes of ivy and licorice saponins with sildenafil citrate (Viagra) and their biological activity

The molecular complexation of triterpene glycosides α-hederin (hederagenin 3-O-α-L-rhamnopyranosyl-(l → 2)-O-α-L-arabinopyranoside), hederasaponin C (hederagenin 3-O-α-L-rhamnopyranosyl-(l → 2)-O-α-L-arabinopyranosyl-28-O-α-L-rhamnopyranosyl-(l → 4)-O-β-D-glucopyranosyl-(l → 6)-O-β-D-glucopyranoside), and glycyram (monoammonium glycyrrhizinate) with sildenafil citrate was investigated for the first time using electrospray ionization mass spectroscopy. The glycosides form a complex in a 1: 1 molar ratio. The influence of the complex on Avena sativa seeds germination and its ichthyotoxicity against Poecilia reticulata were studied.     

Flavonol triglycosides from Magnolia utilis

Three undescribed flavonol triglycosides, rhamnetin-3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)]-β-d-glucopyranoside (champaluangoside A), rhamnetin-3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→6)]-β-d-galactopyranoside (champaluangoside B) and rhamnocitrin-3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→6)]-β-d-glucopyranoside (champaluangoside C), were isolated from Magnolia utilis in addition to eleven known compounds; quercetrin-3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→6)]-β-d-glucopyranoside, oxytroflavoside G, magnoloside A, magnoloside M, magnoloside D, manglieside A, manglieside B, 1,2-di-O-β-d-glucopyranosyl-4-allylbebzene, syringrin, benzyl β-d-allopyranoside and (+)-syringaresinol-O-β-d-glucopyranoside. The structure elucidation of these compounds was based on analyses of physical and spectroscopic data.     

Steroidal saponins of Asparagus adscendens

From the methanol extract of the fruits of Asparagus adscendens sitosterol-β-d-glucoside, two spirostanol glycosides (asparanin A and B) and two furostanol glycosides (asparoside A and B) were isolated and characterized as 3-O-[β-d-glucopyranosyl (1→2)-β-d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, 3-O-{[β-d-glucopyranosyl(1→2)][α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranosyl}-(25S)-5β-spirostan-3β-ol,3-O-{[β-d-glucopyranosyl(1→2)][α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranosyl|} -26-O-(β- d-glucopyranosyl)-22α-methoxy-(25S)-5β-furostan-3β,26-diol and 3-O-{[β-d-glucopyranosyl(1→2)][α-l-rhamnopyranosyl(1→4)]-β-d-glucopyranosyl}-26-O-(β-d-glucopyranosyl)- 25S)-5β-furostan-3β,22α, 26-triol, respectively.     

Molecular complexes of ivy triterpene glycosides with β-cyclodextrin

Molecular complexes of triterpene glycosides such as α-hederin (hederagenin 3-O-α-L-rhamnopyranosyl-(1 → 2)-O-α-L-arabinopyranoside) and hederasaponin C (hederagenin 3-O-α-L-rhamnopyranosyl-(1 → 2)-O-α-L-arabinopyranosyl-28-O-α-L-rhamnopyranosyl-(1 → 4)-O-β-D-glucopyranosyl-(1 → 6)-O-β-D-glucopyranoside) with β-cyclodextrin were synthesized. The complex formation was studied by FTIR spectroscopy. Toxic properties of the molecular complexes were examined.     

Struktur der microphyllinsäure aus dem harz von Convolvulus microphyllus

The structure of microphyllic acid, the main glycosidic acid from the ether soluble resin of Convolvulus microphyllus has been elucidated as the O-α-l-rhamnopyranosyl-(1 → 6)-[O-α-l-rhamopyranosyl -(1 → 4)]-O-β-d-glucopyranosyl-(1 → 3)-O-α-l5-rhamnopyranosyl-(1 → 3)-O-β-d-fucopyranoside of 11-hydroxypalmitic acid, using mainly GLC and mass spectrometry of the derivatized sugars.     

Synthesis of 3- and 2′-fucosyl-lactose and 3,2′-difucosyl-lactose from partially benzylated lactose derivatives

O-β-d-Galactopyranosyl-(1→4)-O-[α-l-fucopyranosyl-(1→3)]-d-glucose has been synthesised by reaction of benzyl 2,6-di-O-benzyl-4-O-(2,3,4,6-tetra-O-benzyl-β-d-galactopyranosyl)-β-d-glucopyranoside with 2,3,4-tri-O-benzyl-α-l-fucopyranosyl bromide in the presence of mercuric bromide, followed by hydrogenolysis. Benzylation of benzyl 3′,4′-O-isopropylidene-β-lactoside, via tributylstannylation, in the presence of tetrabutylammonium bromide or N-methylimidazole, gave benzyl 2,6-di-O-benzyl-4-O-(6-O-benzyl-3,4-O-isopropylidene-β-d-galactopyranosyl)-β-d-glucopyranoside (6). α-Fucosylation of 6 in the presence of tetraethylammonium bromide provided either benzyl 2,6-di-O-benzyl-4-O-[6-O-benzyl-3,4-O-isopropylidene-2-O-(2,3,4-tri-O-benzyl-α-l-fucopyransoyl)-β-d- galactopyranosyl]-β-d-glucopyranoside (13, 73%) or a mixture of 13 (42%) and benzyl 2,6-di-O-benzyl-4-O-[6-O-benzyl-3,4,-O-isopropylidene-2-O-(2,3,4-tri-O-benzyl-α-l-fucopyranosyl)-β-d- galactopyranosyl-3-O-(2,3,4-tri-O-benzyl-α-l-fucopyranosyl)-β-d-glucopyranoside (16, 34%). α-Fucosylation of 13 in the presence of mercuric bromide and 2,6-di-tert-butyl-4-methylpyridine gave 16 (73%). Hydrogenolysis and acid hydrolysis of 13 and 16 afforded O-α-l-fucopyranosyl-(1→2)-O-β-d-galactopyranosyl-(1→4)-d-glucose and O-α-l-fucopyranosyl-(1→2)-O-β-d-galactopyranosyl-(1→4)-O-[α-l-fucopyranosyl-(1→3)]-d-glucose, respectively.