Combined 1H, 13C and 11B NMR and mass spectral assignments of boronate complexes of D‐(+)‐glucose,D‐(+)‐mannose,methyl‐α‐D‐glucopyranoside,methyl‐β‐D‐galactopyranoside and methyl‐α‐D‐mannopyranoside

Complex formation between N‐butylboronic acid and D ‐(+)‐glucose, D ‐(+)‐mannose, methyl‐α‐D ‐glucopyranoside, methyl‐β‐D ‐galactopyranoside and methyl α‐D ‐mannopyranoside under neutral conditions was investigated by ¹H, ¹³C and ¹¹B NMR spectroscopy and gas chromatography–mass spectrometry (GC–MS) D ‐(+)‐Glucose and D ‐(+)‐mannose formed complexes where the boronates are attached to the 1,2:4,6‐ and 2,3:5,6‐positions of the furanose forms, respectively. On the other hand, the boronic acid binds to the 4,6‐positions of the two methyl derivatives of glucose and galactose. Methyl α‐D ‐mannopyranoside binds two boronates at the 2,3:4,6‐positions. ¹¹B NMR was used to show the ring size of the complexed sugars and the boronate. GC–MS confirmed the assignments. Copyright © 2003 John Wiley & Sons, Ltd.     

Novel Carbohydrate‐Appended Metal Complexes for Potential Use in Molecular Imaging

Seven discrete sugar‐pendant diamines were complexed to the {M(CO)₃}⁺ (^99mTc/Re) core: 1,3‐diamino‐2‐propyl β‐D ‐glucopyranoside ( L ¹ ), 1,3‐diamino‐2‐propyl β‐D ‐xylopyranoside ( L ² ), 1,3‐diamino‐2‐propyl α‐D ‐mannopyranoside ( L ³ ), 1,3‐diamino‐2‐propyl α‐D ‐galactopyranoside ( L ⁴ ), 1,3‐diamino‐2‐propyl β‐D ‐galactopyranoside ( L ⁵ ), 1,3‐diamino‐2‐propyl β‐(α‐D ‐glucopyranosyl‐(1,4)‐D ‐glucopyranoside) ( L ⁶ ), and bis(aminomethyl)bis[(β‐D ‐glucopyranosyloxy)methyl]methane ( L ⁷ ). The Re complexes [Re( L ¹ – L ⁷ )(Br)(CO)₃] were characterized by ¹H and ¹³C 1D/2D NMR spectroscopy which confirmed the pendant nature of the carbohydrate moieties in solution. Additional characterization was provided by IR spectroscopy, elemental analysis, and mass spectrometry. Two analogues, [Re( L ² )(CO)₃Br] and [Re( L ³ )(CO)₃Br], were characterized in the solid state by X‐ray crystallography and represent the first reported structures of Re organometallic carbohydrate compounds. Conductivity measurements in H₂O established that the complexes exist as [Re( L ¹ – L ⁷ )(H₂O)(CO)₃]Br in aqueous conditions. Radiolabelling of L ¹ – L ⁷ with [^99mTc(H₂O)₃(CO)₃]⁺ afforded in high yield compounds of identical character to the Re analogues. The radiolabelled compounds were determined to exhibit high in vitro stability towards ligand exchange in the presence of an excess of either cysteine or histidine over a 24 h period.     

Methyl 4‐O‐β‐d‐galactopyranosyl α‐d‐mannopyranoside methanol 0.375‐solvate

Methyl β‐d ‐galactopyranosyl‐(1→4)‐α‐d ‐mannopyranoside methanol 0.375‐solvate, C₁₃H₂₄O₁₁·0.375CH₃OH, (I), was crystallized from a methanol–ethanol solvent system in a glycosidic linkage conformation, with ϕ′ (O5_Gal—C1_Gal—O1_Gal—C4_Man) = −68.2 (3)° and ψ′ (C1_Gal—O1_Gal—C4_Man—C5_Man) = −123.9 (2)°, where the ring is defined by atoms O5/C1–C5 (monosaccharide numbering); C1 denotes the anomeric C atom and C6 the exocyclic hydroxymethyl C atom in the βGalp and αManp residues, respectively. The linkage conformation in (I) differs from that in crystalline methyl α‐lactoside [methyl β‐d ‐galactopyranosyl‐(1→4)‐α‐d ‐glucopyranoside], (II) [Pan, Noll & Serianni (2005). Acta Cryst. C 61 , o674–o677], where ϕ′ is −93.6° and ψ′ is −144.8°. An intermolecular hydrogen bond exists between O3_Man and O5_Gal in (I), similar to that between O3_Glc and O5_Gal in (II). The structures of (I) and (II) are also compared with those of their constituent residues, viz. methyl α‐d ‐mannopyranoside, methyl α‐d ‐glucopyranoside and methyl β‐d ‐galactopyranoside, revealing significant differences in the Cremer–Pople puckering parameters, exocyclic hydroxymethyl group conformations and intermolecular hydrogen‐bonding patterns.     

Condensation and Polycondensation of Terephthaldehyde with Methyl D‐Hexopyranosides

The condensation and polycondensations of terephthaldehyde ( 1 ) and methyl D ‐hexopyranosides (gluco‐, galacto‐ and mannopyranoside) are described. Methyl α‐D ‐glucopyranoside and methyl α‐D ‐galactopyranoside react with 1 to give mono‐ 5 a and 6 a and diacetals 5 b and 6 b . Their structures were confirmed by NMR and IR spectroscopy. The polycondensation of methyl α‐D ‐mannopyranoside ( 4 ) with 1 was studied in various solvents within the temperature range of 80–140°C. Regardless of the conversion or the initial comonomer feed ratios the composition of polycondensates depended on the reaction conditions leading to the formation of materials with diverse solubilities, molecular weights and optical properties. The regioselective polycondensation of 1 and 4 was examined by the ¹H NMR spectroscopy of polymer 7 . In the case of five‐membered cyclic acetal units, mixtures of the endo‐H and exo‐H dioxolan‐2‐yl system diastereomers are formed. Experimental examples of functionalization via ester units in polymer molecules 8 are described and the efficiency of the reaction routes and procedures are evaluated. The molecular weight was estimated by size‐exclusion chromatography (SEC) measurements before and after the functionalization.     

Iodine Promoted Glycosylation with Glycosyl Iodides: α‐Glycoside Synthesis

Glycosidation of fully acetylated glucopyranosyl iodide with methanol under the influence of iodine gave α‐glucoside selectively. Use of less reactive acceptors led to the formation of α/β‐mixtures. Glycosylations with fully benzoylated glucosyl iodide yielded β‐glucosides only. In contrast, iodine-promoted glycosylation of serine and threonine with 2‐azido‐2‐deoxy‐glycosyl iodides, easily obtained in three steps, proceeded smoothly, resulting in only α‐linked products in high yield in most cases.     

Diversity of Chemical Constituents from Saxifraga Montana H.

A thorough phytochemical investigation of the whole plant of Saxifraga montana H. afforded a new glucoside, methyl 6″‐O‐(E)‐p‐hydroxycinnamoxyl‐glucosyringate ( 1 ), and seventeen known natural products, 3‐methyl‐6‐methoxy‐3,4‐dihydroisocoumarin‐8‐O‐β‐D‐glucospyranoside ( 2 ), gallic acid ( 3 ), glucosyringic acid ( 4 ), daphnoretin ( 5 ), chamaejasmoside ( 6 ), myricetin ( 7 ), quercetin ( 8 ), quercetin‐3‐O‐β‐D‐galactopyranoside ( 9 ), quercetin‐3‐O‐α‐L‐arabinoside ( 10 ), quercetin‐3‐O‐β‐D‐glucospyranoside ( 11 ), rutin ( 12 ), quercetin‐3‐O‐β‐D‐glucopyranosyl (6‐1) glucopyranoside ( 13 ), ursolic acid ( 14 ), 5,28‐stigmastadien‐3β‐ol ( 15 ), β‐sitosterol ( 16 ), β‐daucosterin ( 17 ), 6′‐palmitoxyl‐β‐daucosterin ( 18 ). On the basis of various spectroscopic methods, especially intensive 2D‐NMR (COSY, HMQC and HMBC), FAB‐MS and HR‐ESI‐MS techniques, their structures were elucidated.     

葡萄糖苷特异性固相萃取固定相的合成、表征及应用

以马来酰亚胺基修饰凝胶载体,通过β-葡萄糖胺和2-亚氨基硫代烷盐酸盐将作为配基的β-葡萄糖脒连接到载体上,合成了一种葡萄糖苷特异性固相萃取固定相,并对其固相萃取性能进行了表征.该固定相对葡萄糖苷具有特异性识别,并成功用于固相萃取分离葡萄糖苷.     

Systematic Dissection of an Aminopyrrolic Cage Receptor for β‐Glucopyranosides Reveals the Essentials for Effective Recognition

A set of structures designed for the recognition of glucosides has been obtained by systematically destructuring a tripodal aminopyrrolic cage receptor that selectively recognizes octyl‐β‐D ‐glucopyranoside (OctβGlc). NMR spectroscopy and isothermal titration calorimetry binding measurements showed that cleavage of one pillar of the cage was beneficial to the binding properties of the receptor, as long as two residual amino groups of the cleaved pillar were present. Removal of these two residual amino groups produced a dramatic loss of affinity for OctβGlc of the resulting monocyclic analogue of the parent cage receptor. A significant improvement in the binding ability was achieved by replacing one pillar with two aminopyrrolic hydrogen‐bonding arms, despite the loss of a preorganized structure. In contrast to the cage receptor, recognition of OctβGlc was observed, even in a competitive medium (30 % DMF in chloroform). Structural studies in solution, carried out through NMR spectroscopy and molecular modeling calculations, led to the elucidation of the 3D binding modes of the side‐armed monocyclic receptors; this highlighted the key role of the amino groups and demonstrated the occurrence of a rotaxane‐like complex, which featured the octyl chain of the glucoside threaded through the macrocyclic ring.     

Regioselective Benzoylation of 6‐O‐Protected and 4,6‐O‐Diprotected Hexopyranosides as Promoted by Chiral and Achiral Ditertiary 1,2‐Diamines

Monobenzoylation of triols (6‐O‐silylated glycopyranosides) or diols (4,6‐O‐benzylidenated glycopyranosides) with benzoyl chloride and triethylamine at ?60° to 23° is promoted by catalytic amounts of ditertiary 1,2‐diamines. The regioselectivity depends mostly on the structure of the alcohols; it is modulated by the configuration and constitution of the diamines, as shown by comparing the effect of Oriyama's catalyst ((S)‐ 1 and (R)‐ 1 ), N,N,N′,N′‐tetramethylethylenediamine (TMEDA), N,N,N′,N′‐tetraethylethylenediamine (TEEDA), Et₃N, and EtNMe₂. The effect of the catalysts on the reactivity is impaired by their steric hindrance. In agreement with the modest enantioselectivity of the mono‐ and dibenzoylation of rac‐cyclohexane‐1,2‐diol in the presence of Oriyama's catalyst, the influence of these diamines on the regioselectivity is rather limited. While associated with procedural simplicity, these catalysts lead, in a few cases, to higher yields of a single benzoate than established methods, viz. in the preparation of the 3‐O‐benzoyl β‐D ‐glucopyranoside 4 , the 2‐O‐benzoyl α‐D ‐galactopyranoside 22 , the 3‐O‐benzoyl α‐D ‐galactopyranoside 23 , and the benzylidenated 2‐O‐benzoyl α‐D ‐galactopyranoside 44 . The regioselective benzoylation of the benzylidenated β‐D ‐mannopyranoside 47 , leading to 48 , appears to be new.     

Chemical Components of Seriphidium Santolium Poljak

A new biflavonoid glucoside, apigenin‐7‐O‐β‐D‐glucopyranoside‐(3′‐O‐7″)‐quercetin‐3″‐methyl ether ( 1 ) together with twenty known compounds, apigenin ( 2 ), luteolin ( 3 ), chrysoeriol ( 4 ), tricin ( 5 ), hispidulin ( 6 ), pectolinarigenin ( 7 ), eupatilin ( 8 ), 5,7‐dihydroxy‐6,3′,4′,5′‐tetramethoxyflavone ( 9 ), 5,7,4′‐trihydroxy‐6,3′,5′‐trimethoxyflavone ( 10 ), 3,6‐O‐dimethylquercetagetin‐7‐O‐β‐D‐glucoside ( 11 ), 6‐hydroxy‐5,7‐dimethoxy‐coumarin ( 12 ), taraxerol ( 13 ), taraxeryl acetate ( 14 ), a mixture of β‐sitosterol ( 15 ) and stigmasterol ( 16 ), a mixture of the n‐alkyl trans‐p‐coumarates ( 17 ), a mixture of the n‐alkyl trans‐ferulates ( 18 ), 2‐hydroxy‐4,6‐dimethoxyacetophenone ( 19 ), 4‐hydroxy‐2,6‐dimethoxyphenol‐1‐O‐β‐D‐glucopyranoside ( 20 ), and 2‐hydroxycinnamoyl‐β‐D‐glucopyranoside ( 21 ), were isolated from the whole plant of Seriphidium santolium Poljak. The structures of these compounds were determined by means of spectral and chemical studies.     

The Chemical Constituents from the Heartwood of Eucalyptus Citriodora

Nineteen compounds were isolated from the CHCl₃ soluble portion of the heartwood of Eucalyptus citriodora. These compounds included trans‐calamenene (1), T‐muurolol (2), α‐cadinol (3), 2β‐hydroxy‐α‐cadinol (4), 4‐hydroxy‐3,5‐dimethoxybenzaldehyde (5), 4‐hydroxy‐3,5‐dimethoxybenzoic acid (6), linoleic acid (7), squalene (8), α‐tocopherol (9), erythrodiol (10), morolic acid (11), betulonic acid (12), cycloeucalenol (13), cycloeucalenol vernolitate (14), β‐sitosterol (15), β‐sitosteryl‐β‐D‐glucopyranoside (16), β‐sitostenone (17), yangambin (18), sesamin (19). Among them, 14 is a new compound. The structures of these compounds were elucidated on the basis of spectroscopic evidence.     

Constituents of the Whole Herb of Clinoponium laxiflorum

The isolation and identification of twenty‐two components (including one new compound) from the whole herb of Clinoponium laxiflorum (Hay) Matsum (Labiatae) are described. Their structures were determined on the basis of spectral and chemical transformation. One new compound is methyl rosmarinate. The other twenty‐one compounds include three steroids (α‐spinasterol, α‐spinasteryl‐3‐O‐β‐D‐glucopyranoside, and β‐sitosteryl‐3‐O‐β‐glucopyranoside), three triterpenes (oleanolic acid, ursolic acid, and betulinic acid), nine flavonoids (didymin, apigenin‐7‐O‐β‐glucopyranoside, luteolin‐7‐O‐β‐glucopyranoside, isosakuranetin, narigenin, apigenin, luteolin, narirutin, and hesperidin), three lignolic acids (rosmarinic acid, 3‐(3,4‐dihydroxyphenyl)lactic acid, and caffeic acid), and three phenols (4‐hydroxybenzaldehyde, 3,4‐dihydroxybenzaldehyde, and 3,4‐dihydroxybenzoic acid).     

Dye sensitized luminescent europium nanoparticles and its time-resolved fluorometric assay for DNA

High performance liquid chromatography (HPLC) method has been developed for simultaneous quantification of limonoid aglycones and glucosides on a reversed phase C₁₈ column using a binary solvent system, coupled with diode array detector. Seven limonoids such as limonin, nomilin, isolimonic acid, ichangin, isoobacunoic acid, limonin 17-β-d glucopyranoside and deacetyl nomilinic acid 17-β-d glucopyranoside were separated and detected at 210 nm. Furthermore, limonoids were separated, identified and quantified in four varieties of citrus fruits and seeds using developed method. Limonin and limonin glucoside were found to be the predominant limonoid aglycone and glucoside, respectively, in all tested samples. The sensitivity of the method was found to be 0.25–0.50 μg for tested limonoids.     

Two new acylated flavonoid glycosides from Morina nepalensis var. alba Hand.‐Mazz.

From the whole plant of Morina nepalensis var. alba Hand.‐Mazz., two new acylated flavonoid glycosides ( 1 and 2 ), together with four known flavonoid glycosides ( 3–6 ), were isolated. Their structures were determined to be quercetin 3‐O‐[2″′‐O‐(E)‐caffeoyl]‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐galactopyranoside (monepalin A, 1 ), quercetin 3‐O‐[2″′‐O‐(E)‐caffeoyl]‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranoside (monepalin B, 2 ), quercetin 3‐O‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐galactopyranoside (rumarin, 3 ), quercetin 3‐O‐β‐D ‐galactopyranoside ( 4 ), quercetin 3‐O‐β‐D ‐glucopyranoside ( 5 ) and apigenin 4^′‐O‐β‐D ‐glucopyranoside ( 6 ). Their structures were determined on the basis of chemical and spectroscopic evidence. Complete assignments of the ¹H and ¹³C NMR spectra of all compounds were achieved from the 2D NMR spectra, including H–H COSY, HMQC, HMBC and 2D HMQC‐TOCSY spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

Highly E‐Selective and Enantioselective Michael Addition to Electron‐Deficient Internal Alkynes Under Chiral Iminophosphorane Catalysis

A highly E‐selective and enantioselective conjugate addition of 2‐benzyloxythiazol‐5(4H)‐ones to β‐substituted alkynyl N‐acyl pyrazoles is achieved under the catalysis of a P‐spiro chiral iminophosphorane. Simultaneous control of the newly generated central chirality and olefin geometry is possible with a wide array of the alkynyl Michael acceptors possessing different aromatic and aliphatic β‐substituents, as well as the various α‐amino acid‐derived thiazolone nucleophiles. This protocol provides access to structurally diverse, optically active α‐amino acids bearing a geometrically defined trisubstituted olefinic component at the α‐position.     

Clionasterol Glucoside and Acylated Clionasterol Glucosides from Oplismenus burmannii

A new clionasterol glucoside, clionasterol‐[(1'→3α)‐O‐β‐D]‐glucopyranoside ( 1 ), a new acylated clionasterol glucoside, clionasterol‐[6'‐O‐acyl‐(1'→3β)‐O‐b‐D]‐glucopyranoside ( 2 ) and clionasterol ( 3 ) were isolated from the aerial parts of Oplismenus burmannii. The nature and length of fatty acid acyl chains in 2 was identified by alkaline methanolysis of compound 2 . The aglycone fraction on GC‐MS analysis showed three peaks in GC at t_R 49.86 (82.1%), 51.13 (13.3%) and 56.53 (4.6%) min, which were characterized as arachidic acid methyl ester ( a ) oleic acid methyl ester ( b ) and 12‐methyltetradecanoic acid methyl ester ( c ) respectively. Thus 2 was characterized as a mixture of three new compounds, clionasterol‐[6'‐O‐eicosanoyl‐(1'→3β)‐O‐β‐D]‐glucopyranoside ( 2a ), clionasterol‐[6'‐O‐(8Z)‐octa‐deca‐9‐enoyl‐(1'→3β)‐O‐β‐D]‐glucopyranoside ( 2b ) and clionasterol‐[6'‐O‐(12‐methyltetradecanoyl)‐(1'→3β)‐O‐β‐D]‐glucopyranoside ( 2c ).     

Hydrophobic and Hydrophilic Balance and Its Effect on Mesophase Behaviour in Hydroxyalkyl Ethers of Methyl Glucopyranoside

Four series of monosubstituted methyl α‐D ‐glucopyranoside hydroxyalkyl ethers were prepared and their thermotropic and lyotropic self‐organising properties were investigated in terms of the hydrophobic–hydrophilic balance with respect to their molecular structures. The results obtained lead us to a new understanding of the forces that drive the formation of condensed soft‐matter phases.     

Synthesis of C‐Glycosyl Phosphate and Phosphonate,Analogues of N‐Acetyl‐α‐d‐Glucosamine 1‐Phosphate

Synthesis of α‐C‐ethylene phosphate and phosphonate as well as α‐C‐methylene phosphate analogues of N‐acetyl‐α‐d‐glucosamine 1‐phosphate is reported starting from the common perbenzylated 2‐acetamido‐2‐deoxy‐α‐C‐allyl glucoside. Anomerisation of the corresponding amino α‐C‐glucosyl aldehyde to the β‐aldehyde was observed. Thus, both amino α‐ and β‐C‐glucosyl methanol were obtained after reduction.     

Purification and Characterization of Three Galactose Specific Lectins from Sajna (Moringa Oleifera L.) Leaves

Three lectins designated as SLL‐1, SLL‐2 and SLL‐3 were purified from small sized Sajna (Moringa oleifera L.) leaves by gel filtration of 100% ammonium sulfate saturated crude protein extract on Sephadex G‐75 followed by ion‐exchange chromatography on DEAE and affinity chromatography on Sepharose‐4B. The molecular weight of the lectins SLL‐1, SLL‐2 and SLL‐3 were 1,55,000, 1,15,000 and 85,000, respectively, as determined by gel filtration on Sephadex G‐150 and 1,60,000; 1,20,000 and 85,500, respectively, by SDS‐polyacrylamide slab gel electrophoresis. SLL‐1 and SLL‐2 are dimer in nature held together by disulfide bond (s), while SLL‐3 is a monomer. The lectins agglutinated specifically rat red blood cells and the agglutination was inhibited specifically by methyl‐α‐D‐galactopyranoside, methyl‐β‐D‐galactopyranoside and D‐galactose. The lectins SLL‐1, SLL‐2 and SLL‐3 contain 3.9, 3.4 and 2.8% neutral sugar, respectively, and the sugar compositions were glucose for SLL‐1, mannose for SLL‐2 and SLL‐3 contained either N‐acetyl‐D‐glucosamine or N‐acetyl‐D‐galactosamine or both. The lectins exhibited cytotoxicity in brine shrimp lethality bioassay.     

Allosteric Recognition of Homomeric and Heteromeric Pairs of Monosaccharides by a Foldamer Capsule

The recognition of either homomeric or heteromeric pairs of pentoses in an aromatic oligoamide double helical foldamer capsule was evidenced by circular dichroism (CD), NMR spectroscopy, and X‐ray crystallography. The cavity of the host was predicted to be large enough to accommodate simultaneously two xylose molecules and to form a 1:2 complex (one container, two saccharides). Solution and solid‐state data revealed the selective recognition of the α‐⁴C₁‐d ‐xylopyranose tautomer, which is bound at two identical sites in the foldamer cavity. A step further was achieved by sequestering a heteromeric pair of pentoses, that is, one molecule of α‐⁴C₁‐d ‐xylopyranose and one molecule of β‐¹C₄‐d ‐arabinopyranose despite the symmetrical nature of the host and despite the similarity of the guests. Subtle induced‐fit and allosteric effects are responsible for the outstanding selectivities observed.