Triterpene glycosides from Kalopanax septemlobum. VI. Glycosides from leaves of Kalopanax septemlobum var. typicum introduced to crimea

Thirteen known glycosides of hederagenin and oleanolic acid and the three new triterpene glycosides of oleanolic acid-28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester 3-O-β-D-glucopyranosyl-(1→4)-O-β-D-xylopyranosyl-(1→ 3)-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside of oleanolic acid and the 28-O-α-L-rhamnopyranosyl-(1→4)-O-6-O-acetyl-β-D-glucopyranosyl-(1→ 6)-O-β-D-glucopyranosyl esters 3-O-β-D-xylopyranosyl-(1→3)-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside of oleanolic acid and 3-O-β-D-glucopyranosyl-(1→4)-O-β-Dxylopyranosyl-(1→3)-O-α-L-rhamnopyranosyl-(1→ 2)-O-α-L-arabinopyranoside of oleanolic acid were isolated from leaves of Kalopanax septemlobum var. typicum introduced to Crimea. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 40–43, January–February, 2006.     

New polyhydroxysteroids and steroid glycosides from the far east starfishCeramaster patagonicus

Two new polyhydroxysteroids and five new glycosides were isolated from the starfishCeramaster patagonicus and their structures were elucidated: 5α-cholestane-3β,6α,15β,16β,26-pentol, (22E)-5α-cholest-22-ene-3β,6α,8,15α,24-pentol, (22E)-28-O-[O-(2-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-hydroxymethyl-5α-cholest-22-ene-3β,4β, 6α,8,15β,16β,28-heptol (ceramasteroside C₁), (22E)-28-O-[O-(2,4-di-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-hydroxymethyl-5α-cholest-22-ene-3β, 6α,8,15β,16β,28-hexol (ceramasteroside C₂), (22E)-28-O-[O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-hydroxymethyl-5α-cholest-22-ene-3β,6α,8,15β,16β 28-hexol (eramasteroside C₃), (22E)-28-O-[O-(2-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-methyl-5α-cholest-22-ene-3β,4β,6α,8, 15β, 26-hexol (ceramasteroside C₄), and (22E)-28-O-[O-(2-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-xylopyranosyl]-5α-cholest-22-ene-3β,6α,8,15β,24-pentol (ceramasteroside C₅)). Three known polyhydroxysteroids (24-methylene-5α-cholestane-3β,6α,8,15β,16β,26-hexol, 5α-cholestane-3β,6α,8,15β,16β,26-hexol, and 5α-cholestane-3β,6β,15α,16β,26-pentol) were also isolated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 190–195, January, 1997.     

Polysaccharide hydrolases from leaves of Boscia senegalensis: properties of endo-(1-->3)-beta-D-glucanase

The leaves of Boscia senegalensis are traditionally used in West Africa in cereal protection against pathogens, pharmacologic applications, and food processing. Activities of α-amylase, β-amylase, exo-(1→3, 1→4)-β-d-glucanase, and endo-(1→3)-β-d-glucanase were detected in these leaves. The endo-(1→3)-β-d-glucanase (EC3.2.1.39) was purified 203-fold with 57% yield. The purified enzyme is a nonglycosylated monomeric protein with a molecular mass of 36 kDa and pI≥10.3. Its optimal activity occurred at pH 4.5 and 50°C. Kinetic analysis gave V _max, k _cat , and K _m values of 659 U/mg, 395 s⁻¹, and 0.42 mg/mL, respectively, for laminarin as substrate. The use of matrix-assisted laser desorption ionization time-of-flight mass spectrometry and high-performance liquid chromatography revealed that the enzyme hydrolyzes not only soluble but also insoluble (1→3)-β-glucan chains in an endo fashion. This property is unusual for endo-acting (1→3)-β-d-glucanase from plants. The involvement of the enzyme in plant defense against pathogenic microorganisms such as fungi is discussed.     

Triterpene glycosides from Cussonia paniculata. III. Structure of glycosides I1, I2, J1a, J1b, J2, K, L1, and L2 from C. paniculata leaves

Structures of eight triterpene glycosides, of which the 28-O-(2-O-acetyl-and 3-O-acetyl-α-L-rhamnopyranosyl)-(1→4)-O-β-D-glucopyranosyl-(1→ 6)-O-β-D-glucopyranosyl esters of hederagenin 3-O-β-D-glucopyranosyl-(1→ 2)-O-α-L-arabinopyranoside (J_1a and J_1b) were new, from Cussonia paniculata (Araliaceae) leaves were established using chemical and NMR spectroscopic methods. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 149–152, March–April, 2006.     

Synthesis of oligosaccharides related to the HNK-1 antigen. 5. Synthesis of a sulfo-mimetic of the HNK-1 antigenic trisaccharide

2-Aminoethyl 3,6-di-O-sulfo-β-D-glucopyranosyl-(1→3)-β-D-galactopyranosyl-(1→4)-2-acetamido-2-deoxy-β-D-glucopyranoside, which is the sulfo-mimetic of the antigenic trisaccharide HNK-1, and the corresponding monosulfates, viz., 2-aminoethyl 3-O-sulfo-and 2-aminoethyl 6-O-sulfo-β-D-glucopyranosyl-(1→3)-β-D-galactopyranosyl-(1→ 4)-2-acetamido-2-deoxy-β-D-glucopyranosides, were synthesized. 2-Azidoethyl 2,4-di-O-benzoyl-β-D-glucopyranosyl-(1→3)-2,4,6-tri-O-benzoyl-β-D-galactopyranosyl-(1→ 4)-2-acetamido-3,6-di-O-benzyl-2-deoxy-β-D-glucopyranoside served as the common precursor for the sulfated trisaccharides. This compound was synthesized according to the [2+1] pattern from monosaccharidic precursors: 3,6-di-O-acetyl-2,4-di-O-benzoyl-D-glucopyranosyl trichloroacetimidate, allyl 2-O-benzoyl-4,6-O-benzylidene-β-D-galactopyranoside, and 2-azidoethyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-β-D-glucopyranoside. The structures of the glycosyl donors and glycosylation conditions were optimized for the efficient synthesis of the glucosyl-β-(1→3)-galactose disaccharide block and its subsequent transformation into the target trisaccharide sequence. Dedicated to Academician V. A. Tartakovsky on the occasion of his 75th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1593–1607, August, 2007.     

Separation and identification of steroidal compounds with cytotoxic activity against human gastric cancer cell lines <Emphasis Type="Italic">in vitro</Emphasis> from the rhizomes of <Emphasis Type="Italic">Paris polyphylla</Emphasis> var. <Emphasis Type="Italic">chinensis</Emphasis>

A novel steroidal saponin, along with 12 known steroidal compounds, was isolated from the rhizomes of Paris polyphylla var. chinensis. Spectral data, including two-dimensional NMR, showed that the structure of the novel saponin was 3β,21-dihydroxypregnane-5-en-20S-(22,16)-lactone-1-O-α-L-rhamnopyranosyl(1→2)-[β-D-xylopyranosyl(1→3)]-β-D-glucopyranoside. The isolated steroidal compounds were evaluated for their cytotoxic activity on human gastric cancer cell line HepG₂, SGC7901, BxPC3. Diosgenin-3-O-α-L-rhamnopyranosyl(1→2)[α-L-rabinofuranosyl(1→4)]-β-D-glucopyranoside exhibited the most potent cytotoxic activity among the isolated steroids. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 556–560, November–December, 2007.     

Synthesis of aminoethyl glycoside of the oligosaccharide chain of ganglioside Fuc-GM1

2-Aminoethyl glycoside of the hexasaccharide chain of ganglioside Fuc-GM₁ was synthesized by a [3+3] synthetic scheme. At the key step of the synthetic route, glycosylation of the only hydroxyl group at C(4) of the galactose residue in an α-(N-acetylneuraminyl)-(2→3)-β-D-galactopyranosyl-(1→4)-β-D-glucopyranoside derivative with a peracetylated thioglycoside of α-L-fucopyranosyl-(1→2)-β-D-galactopyranosyl-(1→3)-2-trichloroacetamido-2-deoxy-β-D-galactopyranose gave a protected hexasaccharide in high yield. Subsequent removal of the protecting groups gave the target 2-aminoethyl glycoside of the oligosaccharide chain of gan-glioside Fuc-GM₁. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 148–153, January, 2006.     

Minor asterosaponin archasteroside C from the starfish <Emphasis Type="Italic">Archaster typicus</Emphasis>

A new minor asterosaponin (20S)-6-O-{β-d-fucopyranosyl-(1→2)-[β-d-fucopyranosyl-(1→4)-β-d-quinovopyranosyl-(1→2)]-β-d-quinovopyranosyl-(1→3)-β-d-quinovopyranosyl}-3β,6α,20-trihydroxycholest-9(11)-en-23-one 3-sulfate (archasteroside C) was isolated from the starfish Archaster typicus collected in shallow coastal waters of Vietnam. The structure of archasteroside C was determined by 2D NMR spectroscopy and electrospray ionization (ESI) tandem mass spectrometry.     

New class of carbohydrate-based nonionic surfactants: diblock co-oligomers of tri-<Emphasis Type="Italic">O</Emphasis>-methylated and unmodified cello-oligosaccharides

Mixtures of diblock co-oligomers of tri-O-methylated and unmodified cello-oligosaccharides have been found to be amphiphilic, as reported before. In order to clarify their accurate amphiphilic property, diblock co-oligomers of tri-O-methylated and unmodified cello-oligosaccharides with monodispersity, methyl β-d-glucopyranosyl-(1→4)-2,3,6–tri-O-methyl-β-d-glucopyranosyl-(1→4)-2,3,6–tri-O-methyl-β-d-glucopyranosyl-(1→4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1→4)-2,3,6-tri-O-methyl-d-glucopyranoside (1, pentamer), methyl β-d-glucopyranosyl-(1→4)- β-d-glucopyranosyl-(1→4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1→4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1→4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1→4)-2,3,6-tri-O-methyl-d-glucopyranoside (2, hexamer), and methyl β-d-glucopyranosyl-(1→4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1→4)- 2,3,6-tri-O-methyl-d-glucopyranoside (3, trimer) were synthesized independently. These compounds had higher surface activities compared to the mixture of diblock co-oligomers of tri-O-methylated and unmodified cello-oligosaccharides and commercially available methylcellulose (MC) SM-4. This paper describes the methods of synthesis of these compounds, and the influence of amphiphilic character on their surface activity. A new class of carbohydrate-based nonionic surfactant without long alkyl chain was discovered.     

Triterpene glycosides ofHedera canariensis III. Determination of the structures of glycosides L-F1, L-F2, and L-I2 from the leaves of Algerian ivy

The leaves of Algerian ivyHedera canariensis Willd. (Araliaceae) have yielded two new triterpene glycosides — caulophyllogenin 3-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside (L-F₂) and its 28-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-gentiobiosyl ester (L-I₂) - and also the previously known hederagenin 3-O-α-L-rhamnopyranosyl-(1→2)-O-β-D-glucopyranoside (L-F₁). The structures of the glycosides were established on the basis of chemical transformations and¹H and¹³C NMR spectroscopy. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 777–781, November–December, 1998.     

Molecular complexation of the triterpene glycoside hederasaponin C and caffeine in aqueous solution

Molecular complexation of the triterpene glycoside hederasaponin C [hederagenin 3-O-α-L-rhamnopyranosyl-(1→2)-O-β-L-arabinopyranosyl-28-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ether] and caffeine in aqueous solution was studied by UV spectroscopy for the first time. The complex composition, which included two glycosides and one caffeine, was determined using isomolar series and molar ratios. The ichthyotoxicity of the complex and its components against Poecilia reticulata was studied.     

Gangliosides from the starfishEvasterias echinosoma: identification of a disialoganglioside containing 8-O-methyl-N-acetylneuraminic acid andN-formylgalactosamine

Gangliosides were isolated from the starfishEvasterias echinosoma and their structures were elucidated by chemical and physicochemical methods. Two major gangliosides were found to be disialogangliosides, whose carbohydrate chain is based on the trisaccharide β-N-acylgalactosaminyl-(l→3)-β-galactosyl-(l→4)-β-glucose (acyl is formyl or acetyl), both residue at of 8-O-methyl-N-acetylneuraminic acid being attached to theN-acylgalactosamine residue at positions 3 and 6. The minor components are disialogangliosides with linear carbohydrate chains in which the terminal sialic acid residue is attached to the penultimateN-acetylneuraminic acid residue at positions 4, 8, or 9. The lipid part of the gangliosides consists of sphingenine and unsubstituted fatty acids (mainly, palmitic and stearic acids). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 156–161, January, 2000.     

Steroidal glycosides from Allium cyrillii bulbs

Two spirostanol saponins, one of which was a new compound, were isolated among the steroidal glycosides of Allium cyrillii Ten. Bulbs. The structures of these glycosides were established using chemical and spectral analytical methods as β-D-glycopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl-(1 → 4)β-D-galactopyranosyl-(1 → 3)-(25R)-5α-spirostan-2α,3β-diol and β-D-glucopyranosyl-(1 → 2)-[4-O-(3hydroxy-3-methylglutaryl)-β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl-(1 → 4)-β-D-galactopyranosyl(1 → 3)-(25R)-5α-spirostan-2α,3β-diol.     

Gangliosides from the starfishEvasterias echinosoma: identification of a disialoganglioside containing 8-O-methyl-N-acetylneuraminic acid andN-formylgalactosamine

Gangliosides were isolated from the starfishEvasterias echinosoma and their structures were elucidated by chemical and physicochemical methods. Two major gangliosides were found to be disialogangliosides, whose carbohydrate chain is based on the trisaccharide β-N-acylgalactosaminyl-(l→3)-β-galactosyl-(l→4)-β-glucose (acyl is formyl or acetyl), both residue at of 8-O-methyl-N-acetylneuraminic acid being attached to theN-acylgalactosamine residue at positions 3 and 6. The minor components are disialogangliosides with linear carbohydrate chains in which the terminal sialic acid residue is attached to the penultimateN-acetylneuraminic acid residue at positions 4, 8, or 9. The lipid part of the gangliosides consists of sphingenine and unsubstituted fatty acids (mainly, palmitic and stearic acids). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 156–161, January, 2000.     

Synthesis of blockwise alkylated tetrasaccharide–organic quantum dot complexes and their utilization for live cell labeling with low cytotoxicity

Bioimaging is a key to understanding immune responses, cell differentiation, and development. Quantum dots (QDs) conjugated with monoclonal antibodies and other biomolecules are currently utilized for flow cytometry and immunohistochemistry, but monoclonal antibody–QD complexes are of limited use when cell surface markers are not available. In this study, we synthesized novel amphiphilic blockwise alkylated tetrasaccharides and developed a simple method for labeling a wide variety of live cells with organic QDs encapsulated with these carbohydrates. The novel amphiphilic blockwise alkylated tetrasaccharides were as follows: methyl β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-d-glucopyranoside (1), methyl β-d-galactopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-d-glucopyranoside (2), ethyl β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-ethyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-ethyl-d-glucopyranoside, (3), and ethyl β-d-galactopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-ethyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-ethyl-d-glucopyranoside (4). The newly synthesized blockwise alkylated tetrasaccharides spontaneously assembled into micelle-like particles, in which the hydrophobic moiety of the blockwise alkylated tetrasaccharides played an important role. They were less toxic to human cells than octyl β-d-glucopyranoside, a commonly used amphiphilic glucoside. Flow cytometry and confocal laser scanning microscopy revealed that the blockwise alkylated tetrasaccharide–organic QD complexes were stably attached to live cells. The affinity of compounds 1 and 2 to the live cell surface was slightly higher than that of compounds 3 and 4. Because the preparation of these carbohydrate–QD complexes is simple and does not require sophisticated equipment, and because the complexes can be autonomously attached to a wide spectrum of cell lines, they can be used as cell labeling reagents in biomedical studies.     

Two new triterpenoid saponins from <Emphasis Type="Italic">Lysimachia davurica</Emphasis>

Two new saponins were isolated from an ethanol extract of the whole plants of Lysimachia davuria. The new saponins were respectively characterized as 3-O-{β-D-glucopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-α-L-arabinopyranosyl}-3β,28-dihydroxyolean-12-en-30-oic acid-O-[β-D-xylopyranosyl-(1→2)-β-D-glucopyranosyl]-ester (1) and 3-O-{ β-D-glucopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-α-L-arabinopyranosyl}-3β,28-dihydroxyolean-12-en-30-oic acid-O-β-D-glucopyranosyl-ester (2). Their structures were determined by 1D, 2D NMR and MS techniques. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 466–468, September–October, 2007.     

ABA- and BAB-triblock cooligomers of tri-<Emphasis Type="Italic">O</Emphasis>-methylated and unmodified cello-oligosaccharides: syntheses and structure-solubility relationship

Triblock cooligomers consisting of tri-O-methyl-glucopyranosyl and unmodified glucopyranosyl residues, methyl 2,3,4,6-tetra-O-methyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-α-d-glucopyranoside (1: ABA triblock cooligomer; DS = 2.1) and β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1 → 4)-2,3,6-tri-O-methyl-β-d-glucopyranosyl-(1 → 4)-d-glucopyranose (2: BAB triblock cooligomer; DS = 1.8) were prepared. Compound 1 dissolved both in distilled water and chloroform but compound 2 dissolved in distilled water not in chloroform, though compounds 1 and 2 consist of 4 tri-O-methyl-glucopyranosyl and 2 unmodified anhydro glucopyranosyl units.     

New triterpene glycoside from <Emphasis Type="Italic">Cyclamen adzharicum</Emphasis> tubers

Nine pure glycosides were isolated from total saponins of Cyclamen adzharicum Pobed. (Primulaceae). The total chemical structure of cyclamen F, 3β-O-[β-D-Xylp(1→2)]-[β-D-Glcp(1→2)]-(β-D-Glcp(1→4)-α-L-Arap)-16α-hydroxy-13,28-epoxy-30,30-dibutoxyolean, was elucidated using modern physicochemical and spectral methods (NMR, ¹H, ¹³C, HMBC, HMQC, DEPT, COSY, MS). A glycoside with the cyclamen F chemical structure has not been reported and, therefore, is a new organic compound.     

A new hederagenin glycoside from <Emphasis Type="Italic">Nephelium lappaceum</Emphasis>

A new oleane-type triterpene oligoglycoside, hederagenin 3-O-(3-O-acetyl-β-D-xylopyranosyl)-(1→3)-α-L-arabinopyranoside (2), together with four known compounds, hederagenin (1), hederagenin 3-O-(4-O-acetyl-α-L-arabinopyranosyl)-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside (3), hederagenin 3-O-α-L-arabinopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside (4), hederagenin 3-O-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→4)-β-D-xylopyranoside (5), was isolated from the hull of Nephelium lappaceum. All the isolates were obtained from the hull of rambutan for the first time.     

Steroidal glycosides of gitogenin from Allium rotundum

Two new steroidal glycosides were isolated by fractionation of total extracted substances from inflorescences and flower stalks of Allium rotundum (Alliaceae). The structures were determined on the basis of chemical transformations, physical constants, and spectral data as 26-O-β-D-glucopyranosyl-(25R)-5α-furostan2α,3β,22α,26-tetraol 3-O-β-D-glucopyranosyl-(1 → 2)[β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl(1 → 4)-β-D-galactopyranoside (2) and (25R)-5α-spirostan-2α,3β-diol 3-O-β-D-glucopyranosyl-(1 → 3)-βD-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl-(1 → 4)-β-D-galactopyranoside (3).