Feruloyl,caffeoyl, and flavonol glucosides from <Emphasis Type="Italic">Equisetum hyemale</Emphasis>

Feruloyl, caffeoyl, and flavonol glucosides were isolated from the stems of Equisetum hyemale L. The structures of the compounds were elucidated as trans-feruloyl-4-β-glucoside (1), cis-feruloyl-4-β-glucoside (2), trans-caffeoyl-3-β-glucoside (3), kaempferol-3-sophoroside (4), kaempferol-3-sophoroside-7-β-glucoside (5), and herbacetin-3-sophoroside-8-β-glucoside (6) based on the spectral evidence.     

Lecithin organogels with n-alkyl-D- glucosides and n-alkly-D-lactobionamide

 Jelly-like phases formed by mixtures of soybean lecithin with pure n-dodecyl-β-D-glucopyranoside (DDPG), commercial alkylpoly-glucoside (APG) or n-dodecyl-β-D-lactobionamide (DLBA) in decane in the presence of small amounts of water were studied by oscillating rheology and FT-IR-spectroscopy. It was established that the sugar derivatives can modify the rheological properties of lecithin organogels in different ways. The viscosities, the structural relaxation times and the shear moduli decrease with increasing content of DDPG, while the same parameters increase for DLBA. For APG the modulus is increasing while the viscosity and the structural relaxation time are decreasing. By means of FT-IR spectroscopy and examination of the Cole–Cole-plots of the loss modulus vs. the storage modulus it was shown that the sugar derivatives influence both the strength of the hydrogen bonds between the molecules in the polymer-like micelles and the micellar dynamics. Received: 10 November 1997 Accepted: 11 December 1997     

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.     

Determination and Pharmacokinetic Study of Calycosin-7-O-β-d-glucoside in Rat Plasma After Intravenous Administration of Aidi Lyophilizer

Aidi injection is a clinical medicine used in China for the treatment of cancer. Calycosin-7-O-β-d-glucoside is the main effective components of the formulas. In this study, a high performance liquid chromatographic (LC) method was developed to quantify calycosin-7-O-β-d-glucoside in rat plasma using a liquid–liquid extraction and ultraviolet (UV) absorbance detection. LC analysis was performed on a Diamonsil C₁₈ column (200 × 4.6 mm i.d., 5 μm particle size) with isocratic mobile phase consisting of acetonitrile–0.05% phosphoric acid (19.5:80.5, v/v) of a flow rate of 1.0 mL min⁻¹. The linear range was 0.11–17.6 μg mL⁻¹ and the low quantification limit was 0.11 μg mL⁻¹ (S/N = 10). The intra- and inter-day relative standard deviations (RSD) in the measurement of quality control (QC) samples 0.11, 0.22, 1.32 and 8.80 μg mL⁻¹ ranged from 4.1 to 6.3 and 4.3 to 6.2%, respectively. The accuracy was from −6.7 to 4.3% in terms of relative error (RE). Calycosin-7-O-β-d-glucoside was stable in storage at −20 °C for 2 weeks and stable after three freeze–thaw cycles in rat plasma. This method was validated for specificity, accuracy, precision and was successfully applied to pharmacokinetic study of calycosin-7-O-β-d-glucoside in rat plasma after intravenous administration of Aidi lyophilizer.     

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.     

New triterpenoid glycosides fromThalictrum minus L.

Two triterpenoid diglycosides of the cycloartane series were isolated from the terrestrial part ofThalictrum minus L. (Ranunculaceae). Genins of these glycosides are side-chain structural isomers—3-O-β-d-galactopyranosyl-29-O-β-d-glucopyranosyl-9β, 19-cyclo-20(S)-lanost-24(Z)-ene-3β, 16β, 22(S), 26, 29-pentaol and 3-O-β-d-galactopyranosyl-29-O-β-d-glucopyranosyl-9β, 19-cyclo-20(S)-lanost-25-ene-3β, 16β,22(S), 24ζ, 29-pentaol. The structures of these glycosides were established using 1D and 2D NMR spectroscopy and FAB mass spectrometry. For Part 9, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1434–1437, July, 1998.     

Stereochemical aspects of micellar properties of esterified glucoside surfactants in water: apparent molar volume, adiabatic compressibility, and aggregation number

 The apparent molar volume and the apparent molar adiabatic compressibility of the sugar-based surfactants methyl 6-O-octanoyl-α-d-glucopyranoside (α-MOnG), methyl 6-O-octanoyl-β-d-glucopyranoside (β-MOnG), and octyl β-d-glucoside were measured over a wide concentration range. Also, the aggregation number of their micelles was determined from the Debye plot using static light scattering data. It was found that the micellar aggregation number for α-MOnG is 179 at 35 °C, which is 1.5 times larger than that for β-MOnG, suggesting that the anomerism of the head group influences the packing of the monomers during micelle formation. Received: 30 September 1999 Accepted: 15 December 1999     

Polar steroidal compounds from the Far-Eastern starfish <Emphasis Type="Italic">Lethasterias fusca</Emphasis>

Nine steroidal compounds including three new steroidal glycosides, viz., sodium (24S)-3,24-di-O-(β-D-xylopyranosyl)-5α-cholestane-3β,6β,8,15α,24-pentol 15-sulfate (fuscaside A), (24S)-3,24-di-O-(β-D-xylopyranosyl)-5α-cholestane-3β,6β,8,15α,24-pentol (fuscaside B), and (22E,24R)-24-O-(β-D-xylopyranosyl)-5α-cholest-22-ene-3β,6α,8,15β,24-pentol (desulfated minutoside A); three previously known glycosides, viz., distolasterosides D₁ and D₂ and pycno-podioside A; two previously known polyhydroxysteroids, viz., 5α-cholestane-3β,6α,8,15β,16β,26-hexaol and 5α-cholestan-3β,4β,6α,7⇇8,15β,16β,26-octol; and the known sodium 24,25-dihydro-marthasterone 3-sulfate were isolated from the Far-Eastern starfish Lethasterias fusca. The structures of these compounds were elucidated by NMR spectroscopy and mass spectrometry. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 196–200, January, 2008.     

Lyotropic and thermotropic behavior of Alkylglucosides and related compounds

 The phase diagram of the binary system composed of octyl-β-D-glucopyranoside and water was investigated and the phase boundaries were determined. Polarising optical microscopy was used to define the different phases, proton and deuterium NMR experiments to define the region of existence of the different phases and to obtain information on axiality and head group solvation. DSC experiments were performed to determine the thermal transitions from solid to thermotropic liquid crystals for octyl-β-D-gluco-pyranoside, the related alkylglucosides or maltosides, and to gain information on the role played by sugar units in the thermodynamics of such phase transitions. Received: 15 May 1997 Accepted: 08 September 1997     

Synthesis of diblock copolymers with cellulose derivatives. 3. Cellulose derivatives carrying a single pyrene group at the reducing-end and fluorescent studies of their self-assembly systems in aqueous NaOH solutions

Novel cellobiose and cellulose (DP _n =ca. 30) derivatives, N-(1-pyrenebutyloyl)-4-O-(β-d-glucopyranosyl)-β-d-glucopyranosylamine (6), N-(15-(1-pyrenebutyloylamino)-pentadecanoyl)-4-O-(β-d-glucopyranosyl)-β-d-glucopyranosylamine (7), N-(1-pyrenebutyloyl)-β-cellulosylamine (13), N-(15-(1-pyrenebutyloylamino)-pentadecanoyl)-β-cellulosylamine (14) carrying a pyrene group as a single fluorescent probe at the reducing end, were prepared in order to investigate their self-assembly systems in solutions. The relative intensity of the excimer emission at ca. 480 nm due to dimerized pyrenes (intensity I _E) to the monomer emission at ca. 380 nm due to isolated pyrene (intensity I _M), i.e., I _E/I _M, was monitored in various solutions. In water/dimethyl sulfoxide (DMSO) mixed solvent (0–98%, v/v), the ratio I _E/I _M remained low (0.04) for compound 6 over the range of water concentrations, indicating that pyrenes at C-1 position of compound 6 were diffused. On the other hand, the ratio I _E/I _M increased (0.04–4.96) for compound 7 with the increase in water concentration, indicating that pyrenes at C-1 position were associated. In aqueous NaOH solutions (4.4–17.5%, w/w), compound 14 showed a large increase in the ratio I _E/I _M (0.84–8.14) with the increase in NaOH concentration, compared to compound 13 (0.06–0.41). It was found that the association of hydrophobic groups at the reducing-end of cellulose could be controlled by the hydrophilic–hydrophobic balance of compounds and the solvent polarity.     

Mild Pfitzner—Moffat oxidation of the (1→3)-β-D-glucan from Saccharomyces cerevisiae

The structure of the cell wall glucan isolated from the industrial strain of Saccharomyces cerevisiae was characterized as to be composed of a linear (1→3)-β-D-glucan chain with single β-D-glucopyranosyl residues attached to every ninth backbone unit by (1→6)-glycosidic linkages. Mild oxidation of this β-D-glucan with a dimethyl sulfoxide—acetic anhydride reagent yielded an “oxidized” glucan with aldehyde groups introduced at C-6 and carbonyl oxygens located at C-2 and C-4 of the glucopyranosyl rings. The conversion of the oxidized glucan into the polyoxime was used to study the progress of oxidation and to establish the carbonyl groups distribution in this new reactive polysaccharide derived from baker’s yeast cell wall.     

Biotransformation of Paeonol and Emodin by Transgenic Crown Galls of <Emphasis Type="Italic">Panax quinquefolium</Emphasis>

Two aromatic substrates, paeonol (1) and emodin (2), were biotransformed by using transgenic crown galls of Panax quinquefolium. Four biotransformed products (3–6) were isolated and identified by physicochemical and spectral methods. A β-glucoside (3, 73.2% of biotransformation yield) and a 1-(2,4-dimethoxyphenyl)- ethanone (4, 8.03%) were isolated from the suspension cultures after 7-day incubation of substrate 1. Upon administration of substrate 2, another β-glucoside [emodin-6-O-β-d-glucopyranoside (5), 19.2%] and a hydroxylated derivative, citreorosein (6, 54.6%), were also obtained. The results demonstrate that transgenic crown galls of P. quinquefolium have the capacities to catalyze glycosylation, hydroxylation, and methylation reactions in the plant cells on those aromatic compounds.     

Comparison and characterization of polysaccharides from natural and cultured <Emphasis Type="Italic">Cordyceps</Emphasis> using saccharide mapping

Comparison and characterization of polysaccharides from natural and cultured Cordyceps on the basis of their chemical characteristics such as glycosidic linkages were performed for the first time using saccharide mapping. The results showed that polysaccharides from most of the natural and cultured Cordyceps had similar responses to enzymatic digestion. These polysaccharides mainly contained (1→4)-β-D-glucosidic linkages, and (1→4)-α-glucosidic, (1→6)-α-glucosidic, 1,4-β-D-mannosidic, as well as (1→4)-α-D-galactosiduronic linkages also existed in some polysaccharides. Especially, natural and cultured Cordyceps polysaccharides could be discriminated on the basis of high performance liquid chromatography profiles of pectinase hydrolysates, which is helpful to control the quality of polysaccharides from Cordyceps.     

Anionic–Nonionic Mixed Surfactant Systems: Micellar Interaction and Thermodynamic Behavior

The interactions between an anionic surfactant, viz., sodium dodecylbenzenesulfonate and nonionic surfactants with different secondary ethoxylated chain length, viz., Tergitol 15-S-12, Tergitol 15-S-9, and Tergitol 15-S-7 have been studied in the present article. An attempt has also been made to investigate the effect of ethoxylated chain length on the micellar and the thermodynamic properties of the mixed surfactant systems. The micellar properties like critical micelle concentration (CMC), micellar composition (X_A), interaction parameter (β), and the activity coefficients (f_A and f_NI) have been evaluated using Rubingh's regular solution theory. In addition to micellar studies, thermodynamic parameters like the surface pressure (Π_CMC), surface excess values (Γ_CMC), average area of the monomers at the air–water interface (A_avg), free energy of micellization (ΔG_m), minimum energy at the air–water interface (G_min), etc., have also been calculated. It has been found that in mixtures of anionic and nonionic secondary ethoxylated surfactants, a surfactant containing a smaller ethoxylated chain is favored thermodynamically. Additionally, the adsorption of nonionic species on air/water interface and micelle increases with decreasing secondary ethoxylated chain length. Dynamic light scattering and viscometric studies have also been performed to study the interactions between anionic and nonionic surfactants used.     

The Effect of Anomeric Head Groups, Surfactant Hydrophilicity, and Electrolytes onn-Alkyl Monoglucoside Microemulsions

The effects of the variables of head group structure and salt concentration on microemulsions formed in mixtures of water, alkyl ethylene glycol ethers (C_kOC₂OC_k), andn-alkyl β- -glucopyranosides (C_mβG₁) are explored. Phase behavior of mixtures containing an anomer of the surfactant (n-alkyl α- -glucopyranoside, C_mαG₁), or surfactants with long head groups (n-alkyl maltopyranosides, C_mG₂), or NaCl or NaClO₄as electrolyte are systematically reported as a function of temperature and composition. The substitution ofn-alkyl α- -glucopyranosides forn-alkyl β- -glucopyranosides causes precipitation under some conditions in all mixtures studied. These solubility boundaries begin in the water–surfactant binary mixture at the Krafft boundary, then extend to high concentrations of both surfactant and oil. Increasing the effective length of the surfactant head group by adding C_mG₂to water–C_kOC₂OC_k–C_mβG₁mixtures moves the phase behavior dramatically up in temperature when even small amounts of C_mG₂are used. Adding a lyotropic electrolyte, NaCl, to water–C_kOC₂OC_k–C_mβG₁mixtures moves the phase behavior down in temperature, while the hydrotropic electrolyte NaClO₄moves the phase behavior up in temperature.     

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.     

Flavonoids from the aerial part of <Emphasis Type="Italic">Vicia subvillosa</Emphasis>

The new flavone glucoside viscioside, luteolin-4′-O-β-D-galactopyranoside, in addition to the known flavonoids apigenin, luteolin, quercetin, cinaroside, luteolin-4′-O-β-D-glucoside, and isoquercitrin were isolated from the aerial part of Vicia subvillosa. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 30–31, January–February, 2007.     

Synthesis of saccharide precursors for preparation of potential inhibitors of glycosyltranferases

Ethyl 6-O-tert-butyldimethylsilyl-3,4-di-O-acetyl-2-thio-α-D-fructofuranoside (Va), its β-analog (Vb); as well as benzyl 6-O-tert-butyldimethylsilyl-3,4-di-O-acetyl-2-thio-α-D-fructofuranoside (Xa) and its β-analog (Xb), having an unprotected OH group at C-1, were prepared by sequential synthesis starting from commercially available D-fructose. These compounds represent suitable nucleophiles for the preparation of model carbohydrate mimetics of a glycosyltransferase inhibitor type in transition state. The structures of all compounds were confirmed by NMR spectral data and elemental analyses.     

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.     

Facile synthesis of chiral <Emphasis Type="Italic">N</Emphasis>-glycosylated amino acids

Five designed chiral glycosylated amino acids have been synthesized for the first time by coupling of 1,3,4,6-tetra-O-acetyl-β-D-glucosamine sulfate (2), previously prepared by direct acetylation of D-glucosamine hydrochloride with acetic anhydride, with chiral Fmoc-protected amino acids and DIC, HOBt, and DIEA under mild conditions. The structures of these new compounds were characterized by IR, ¹H NMR, and ¹³C NMR spectroscopy and ESI MS.