Complexation of 4‐dimethylaminoazobenzene with various kinds of cyclodextrins: Effects of cyclodextrins on the thermal cis‐to‐trans isomerization

On the basis of the change in electronic and induced circular dichroism spectra for complex formation, the complexation of 4‐dimethylaminoazobenzene (DAAB) with four kinds of cyclodextrins (α‐ and β‐cyclodextrin (CD), heptakis(2,6‐di‐O‐methyl)‐β‐cyclodextrin, and heptakis(2,3,6‐tri‐O‐methyl)‐β‐cyclodextrin) was studied in methanol–water and dimethyl sulfoxide–water mixtures. It was found that the trans and cis isomers of DAAB form two different types of complex (inclusion and lid type) with CDs, depending on the kinds of CDs and solvents. Further, we have examined the effect of CDs on the thermal cis‐to‐trans isomerization of DAAB. The accelerated or decelerated effect on the thermal isomerization was observed upon adding CDs. The effects of CDs on the thermal isomerization are discussed in connection with the complexation of the cis‐isomer of DAAB with CDs. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 481–487, 2002     

Physical properties of diblock methylcellulose derivatives with regioselective functionalization patterns: First direct evidence that a sequence of 2,3,6‐tri‐O‐methyl‐glucopyranosyl units causes thermoreversible gelation of methylcellulose

This article describes detailed structure‐property relationships of 5 regioselectively methylated celluloses and 10 diblock cellulose derivatives with regioselective functionalization patterns: methyl 2,3,6‐tri‐O‐ ( 1 , 236MC), methyl 2,3‐di‐O‐ ( 2 , 23MC), methyl 2,6‐di‐O‐ ( 3 , 26MC), methyl 3‐O‐ ( 4 , 3MC), methyl 6‐O‐methyl‐cellulosides ( 5 , 6MC), methyl β‐D‐glucopyranosyl‐(1→4)‐2,3,6‐tri‐O‐methyl‐ ( 6 , G‐236MC), methyl β‐D‐glucopyranosyl‐(1→4)‐2,3‐di‐O‐methyl‐ ( 7 , G‐23MC), methyl β‐D‐glucopyranosyl‐(1→4)‐2,6‐di‐O‐methyl‐ ( 8 , G‐26MC), methyl β‐D‐glucopyranosyl‐(1→4)‐3‐O‐methyl‐ ( 9 , G‐3MC), methyl β‐D‐glucopyranosyl‐(1→4)‐6‐O‐methyl‐ ( 10 , G‐6MC), methyl β‐D‐glucopyranosyl‐(1→4)‐β‐D‐glucopyranosyl‐(1→4)‐2,3,6‐tri‐O‐methyl‐ ( 11 , GG‐236MC), methyl β‐D‐glucopyranosyl‐(1→4)‐β‐D‐glucopyranosyl‐(1→4)‐2,3‐di‐O‐methyl‐ ( 12 , GG‐23MC), methyl β‐D‐glucopy‐ranosyl‐(1→4)‐β‐D‐glucopyranosyl‐(1→4)‐2,6‐di‐O‐methyl‐ ( 13 , GG‐26MC), methyl β‐D‐glucopyranosyl‐(1→4)‐β‐D‐glucopyranosyl‐(1→4)‐3‐O‐methyl‐ ( 14 , GG‐3MC), and methyl β‐D‐glucopyranosyl‐(1→4)‐β‐D‐glucopyranosyl‐(1→4)‐6‐O‐methyl‐cellulosides ( 15 , GG‐6MC). Surface tension, differential scanning calorimetry, fluorescence, and dynamic light scattering measurements of aqueous solutions of compounds 1 – 15 revealed that there was no relationship between aggregation behaviors and gel formation, gelation occurred only when the hydrophobic environments formed by hydrophobic interactions between the sequences of 2,3,6‐tri‐O‐methyl‐glucopyranosyl units upon heating. The diblock structure consisting of cellobiosyl block and approx. ten 2,3,6‐tri‐O‐methyl‐glucopyranosyl units was of crucial importance for thermoreversible gelation of methylcellulose. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1539–1546, 2011     

2,3,3′,6‐Tetra‐O‐acetyl‐4,1′,6′‐trichloro‐4,1′,4′,6′‐tetradeoxygalactosucrose

At 160 K, one of the Cl atoms in the furanoid moiety of 3‐O‐acetyl‐1,6‐di­chloro‐1,4,6‐tri­deoxy‐β‐d ‐fructo­furan­osyl 2,3,6‐tri‐O‐acetyl‐4‐chloro‐4‐deoxy‐α‐d ‐galacto­pyran­oside, C₂₀H₂₇­Cl₃O₁₁, is disordered over two orientations, which differ by a rotation of about 107° about the parent C—C bond. The conformation of the core of the mol­ecule is very similar to that of 3‐O‐acetyl‐1,4,6‐tri­chloro‐1,4,6‐tri­deoxy‐β‐d ‐tagato­furanos­yl 2,3,6‐tri‐O‐acetyl‐4‐chloro‐4‐deoxy‐α‐d ‐galacto­pyran­oside, particularly with regard to the conformation about the glycosidic linkage.     

Intramolecular Oxidative O‐Demethylation of an Oxoferryl Porphyrin Complexed with a Per‐O‐methylated β‐Cyclodextrin Dimer

The intramolecular oxidation of ROCH₃ to ROCH₂OH, where the latter compound spontaneously decomposed to ROH and HCHO, was observed during the reaction of the supramolecular complex (met‐hemoCD3) with cumene hydroperoxide in aqueous solution. Met‐hemoCD3 is composed of meso‐tetrakis(4‐sulfonatophenyl)porphinatoiron(III) (Fe^IIITPPS) and a per‐O‐methylated β‐cyclodextrin dimer having an ‐OCH₂PyCH₂O‐ linker (Py=pyridine‐3,5‐diyl). The O=Fe^IVTPPS complex was formed by the reaction of met‐hemoCD3 with cumene hydroperoxide, and isolated by gel‐filtration chromatography. Although the isolated O=Fe^IVTPPS complex in the cyclodextrin cage was stable in aqueous solution at 25 °C, it was gradually converted to Fe^IITPPS (t_1/2=7.6 h). This conversion was accompanied by oxidative O‐demethylation of an OCH₃ group in the cyclodextrin dimer. The results indicated that hydrogen abstraction by O=Fe^IVTPPS from ROCH₃ yields HO‐Fe^IIITPPS and ROCH₂^.. This was followed by radical coupling to afford Fe^IITPPS and ROCH₂OH. The hemiacetal (ROCH₂OH) immediately decomposed to ROH and HCHO. This study revealed the ability of oxoferryl porphyrin to induce two‐electron oxidation.     

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.     

Four new ursane‐type saponins from Morina nepalensis var. alba

Four new ursane‐type saponins, monepalosides C–F, together with a known saponin, mazusaponin II, were isolated from Morina nepalensis var. alba Hand.‐Mazz. Their structures were determined to be 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[alpha;‐L ‐rhamnopyranosyl‐(1 → 2)]‐α‐L ‐arabinopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside C, 1 ), 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[alpha;‐L ‐rhamnopyranosyl‐(1 → 2)]‐β‐D ‐xylopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside D, 2 ), 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[beta;‐D ‐glucopyranosy‐(1 → 2)]‐α‐L ‐arabinopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside E, 3 ) and 3‐O‐β‐D ‐xylopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranoside (monepaloside F, 4 ) on the basis of chemical and spectroscopic evidence. 2D NMR techniques, including ¹H–¹H COSY, HMQC, 2D HMQC‐TOCSY, HMBC and ROESY, and selective excitation experiments, including SELTOCSY and SELNOESY, were utilized in the structure elucidation and complete assignments of ¹H and ¹³C NMR spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

6‐TIPS‐β‐Cyclodextrin‐Modified Fe3O4 for Facile Enantioseparation of 1‐(1‐Naphthyl)ethylamine

A new type of chiral magnetic nanoparticle was prepared from covalently linked magnetic nanoparticles (Fe₃O₄) and heptakis‐(6‐O‐triisopropylsilyl)‐β‐cyclodextrin (6‐TIPS‐β‐CD). The resulting selectors (TIPS‐β‐CD‐MNPs) combined the good magnetic properties Fe₃O₄ and efficient chiral recognition ability of 6‐TIPS‐β‐CD. The enantioselectivity of TIPS‐β‐CD‐MNPs towards 1‐(1‐naphthyl)ethylamine was six times higher than that of the parent β‐CD modified Fe₃O₄ particles.     

Comparative evaluation of a one‐pot strategy for the preparation of β‐cyclodextrin‐functionalized monoliths: Effect of the degree of amino substitution of β‐cyclodextrin on the column performance

To further evaluate the feasibility and applicability of the one‐pot strategy in monolithic column preparation, two novel β‐cyclodextrin‐functionalized organic polymeric monoliths were prepared using two β‐cyclodextrin derivatives, i.e. mono(6‐amino‐6‐deoxy)‐β‐cyclodextrin and heptakis(6‐amino‐6‐deoxy)‐β‐cyclodextrin. In this improved method, mono(6‐amino‐6‐deoxy)‐β‐cyclodextrin or heptakis(6‐amino‐6‐deoxy)‐β‐cyclodextrin reacted with glycidyl methacrylate to generate the corresponding functional monomers and were subsequently copolymerized with ethylene dimethacrylate. The polymerization conditions for both monoliths were carefully optimized to obtain satisfactory column performance with respect to column efficiency, reproducibility, permeability, and stability. The obtained poly(glycidyl methacrylate‐mono(6‐amino‐6‐deoxy)‐β‐cyclodextrin‐co‐ethylene dimethacrylate) and poly(glycidyl methacrylate‐heptakis(6‐amino‐6‐deoxy)‐β‐cyclodextrin‐co‐ethylene dimethacrylate) monoliths exhibited a uniform structure, good permeability, and mechanical stability as indicated by scanning electron microscopy and micro‐high‐performance liquid chromatography experimental results. Because of the probable existence of multi‐glycidyl methacrylate linking spacers on the poly(glycidyl methacrylate‐heptakis(6‐amino‐6‐deoxy)‐β‐cyclodextrin‐co‐ethylene dimethacrylate) monolith, the effect of the ratio of glycidyl methacrylate/heptakis(6‐amino‐6‐deoxy)‐β‐cyclodextrin was especially studied, and satisfactory reproducibility could still be achieved by strictly controlling the composition of the polymerization mixture. To investigate the effect of the degree of amino substitution of β‐cyclodextrin on column performance, a detailed comparison of the two monoliths was also carried out using series of analytes including small peptides and chiral acids. It was found that the β‐cyclodextrin‐functionalized monolith with mono‐glycidyl methacrylate linking spacers demonstrated better chiral separation performance than that with multi‐glycidyl methacrylate linking spacers.     

Synthesis of well‐defined 7‐arm and 21‐arm poly(N‐isopropylacrylamide) star polymers with β‐cyclodextrin cores via click chemistry and their thermal phase transition behavior in aqueous solution

The syntheses of well‐defined 7‐arm and 21‐arm poly(N‐isopropylacrylamide) (PNIPAM) star polymers possessing β‐cyclodextrin (β‐CD) cores were achieved via the combination of atom transfer radical polymerization (ATRP) and click reactions. Heptakis(6‐deoxy‐6‐azido)‐β‐cyclodextrin and heptakis[2,3,6‐tri‐O‐(2‐azidopropionyl)]‐β‐cyclodextrin, β‐CD‐(N₃)₇ and β‐CD‐(N₃)₂₁, precursors were prepared and thoroughly characterized by nuclear magnetic resonance and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. A series of alkynyl terminally functionalized PNIPAM (alkyne‐PNIPAM) linear precursors with varying degrees of polymerization (DP) were synthesized via atom transfer radical polymerization (ATRP) of N‐isopropylacrylamide using propargyl 2‐chloropropionate as the initiator. The subsequent click reactions of alkyne‐PNIPAM with β‐CD‐(N₃)₇ and β‐CD‐(N₃)₂₁ led to the facile preparation of well‐defined 7‐arm and 21‐arm star polymers, namely β‐CD‐(PNIPAM)₇ and β‐CD‐(PNIPAM)₂₁. The thermal phase transition behavior of 7‐arm and 21‐arm star polymers with varying molecular weights were examined by temperature‐dependent turbidity and micro‐differential scanning calorimetry, and the results were compared to those of linear PNIPAM precursors. The anchoring of PNIPAM chain terminal to β‐CD cores and high local chain density for star polymers contributed to their considerably lower critical phase separation temperatures (T_c) and enthalpy changes during phase transition as compared with that of linear precursors. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 404–419, 2009     

Selectivity tuning of cyclodextrin derivatives by specific substitution

A new, highly enantioselective cyclodextrin derivative combining the properties of heptakis(6‐O‐tert‐butyldimethylsilyl‐2,3‐di‐O‐methyl)‐β‐cyclodextrin and heptakis(2,3‐di‐O‐acetyl‐6‐O‐tert‐butyldimethylsilyl)‐β‐cyclodextrin was prepared by exchanging a methyl group for an acetyl substituent in a single glucose unit of heptakis(6‐O‐tert‐butyldimethylsilyl‐2,3‐di‐O‐methyl)‐β‐cyclodextrin. A comparative evaluation of the separation capabilities showed that the enantioselectivity of both “parent” cyclodextrin derivatives is transferred to the new chiral stationary phase.     

A mixed cyclodextrin‐biphenyl thermotropic liquid crystal: Synthesis,liquid‐crystalline properties,and supramolecular organization

A well‐defined structure liquid crystal heptakis [6‐deoxy‐6‐(1‐H‐1,2,3‐triazol‐4‐yl)(methyl)6‐(4‐methoxybiphenyl‐4′‐yloxy) hexanoyl]‐β‐cyclodextrin (H6B‐β‐CD) was synthesized from propargyl 6‐(4‐methoxybiphenyl‐4′‐yloxy) hexanoate (P6B) and heptakis (6‐deoxy‐6‐azido)‐β‐cyclodextrin ((N₃)₇‐β‐CD) by click reaction. The chemical structure of H6B‐β‐CD was confirmed by ¹H NMR, FTIR, and MALDI‐TOF MS. The thermal stability of the compound was investigated by thermogravimetric analysis (TGA). The liquid crystalline behavior was studied by differential scanning calorimetry (DSC), polarizing optical microcopy (POM), and wide‐angle X‐ray diffraction (WAXD) measurement. These investigations have shown that the supramolecular structure of H6B‐β‐CD are consisted of a large scale ordered lamellar structure and a small scale ordered structure (SmE) at low temperature region. As the temperature increases, the small scale structure becomes disordered relatively in the first instance, from smectic E to smectic A. Then, the lamellar structure collapses and nematic phase and isotropic phase are observed in sequence. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2838–2845, 2010     

Photoirradiation surface molecularly imprinted polymers for the separation of 6‐O‐α‐d‐maltosyl‐β‐cyclodextrin

Photoirradiation surface molecularly imprinted polymers for the separation of 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin were synthesized using functionalized silica as a matrix, 4‐(phenyldiazenyl)phenol as a light‐sensitive monomer, and 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin as a template. Fourier transform infrared spectroscopy results indicated that 4‐(phenyldiazenyl)phenol was grafted onto the surface of functionalized silica. The obtained imprinted polymers exhibited specific recognition toward 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin. Equilibrium binding experiments showed that the photoirradiation surface molecularly imprinted polymers obtained the maximum adsorption amount of 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin at 20.5 mg/g. In binding kinetic experiments, the adsorption reached saturation within 2 h with binding capacity of 72.8%. The experimental results showed that the adsorption capacity and selectivity of imprinted polymers were effective for the separation of 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin, indicating that imprinted polymers could be used to isolate 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin from a conversion mixture containing β‐cyclodextrin and maltose. The results showed that the imprinted polymers prepared by this method were very promising for the selective separation of 6‐O‐α‐d ‐maltosyl‐β‐cyclodextrin.     

Enantioselective comprehensive two‐dimensional gas chromatography of lavender essential oil

The enantiomeric composition of several chiral markers in lavender essential oil was studied by flow modulated comprehensive two‐dimensional gas chromatography operated in the reverse flow mode and hyphenated to flame ionization and quadrupole mass spectrometric detection. Two capillary column series were used in this study, 2,3‐di‐O‐ethyl‐6‐O‐tert‐butyldimethylsilyl‐β‐cyclodextrin or 2,3,6‐tri‐O‐methyl‐β‐cyclodextrin, as the chiral column in the first dimension and α polyethylene glycol column in the second dimension. Combining the chromatographic data obtained on these column series, the enantiomeric and excess ratios for α‐pinene, β‐pinene, camphor, lavandulol, borneol, and terpinen‐4‐ol were determined. This maybe a possible route to assess the authenticity of lavender essential oil.     

Structure elucidation and total assignment of 1H and 13C NMR data for a new bisdesmoside saponin from Cordia piauhiensis

Extensive 1D (¹H NMR, HBBD‐¹³C NMR, DEPT‐¹³C NMR) and 2D (COSY, TOCSY, NOESY, HMQC and HMBC) NMR analysis was used to characterize the structure of a new bisdesmoside saponin isolated from the methanol extract of stems of Cordia piauhiensis Fresen as 3β‐O‐[α‐L ‐rhamnopyranosyl‐(1 → 2)‐β‐D ‐glucopyranosyl]ursolic acid 28‐O‐[β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranosyl] ester. Copyright © 2003 John Wiley & Sons, Ltd.     

1H and 13C NMR and X‐ray diffraction data for a diosgenyl N,O‐protected glucopyranoside

The assignments of ¹H and ¹³C NMR chemical shifts together with x‐ray diffraction data for synthesized diosgenyl 3,4,6‐tri‐O‐acetyl‐2‐deoxy‐2‐tetrachlorophthalimido‐β‐D ‐glucopyranoside are described. The structure of this glycoside was established by using homo‐ and heteronuclear two‐dimensional NMR techniques. X‐ray diffraction data for this compound are also reported. Copyright © 2002 John Wiley & Sons, Ltd.     

Two new complex triterpenoid saponins from Gledistsia dolavayi Franch.

Two new triterpenoid saponins, gledistside A ( 1 ) and gledistside B ( 2 ), isolated from the fruits of Gledistsia dolavayi Franch., were characterized as the 3,28‐O‐bisdesmoside of echinocystic acid acylated with monoterpene carboxylic acids. On the basis of spectroscopic and chemical evidence, their structures were elucidated as 3‐O‐β‐D ‐xylopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl‐28‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→4)‐[β‐D ‐galactopyranosyl‐(1→2)]‐α‐L ‐rhamnopyranosyl‐(1→2)‐{6‐O‐[2,6‐dimethyl‐6(S)‐hydroxy‐2‐trans‐2,7‐octadienoyl]}‐β‐D ‐glucopyranosylechinocystic acid ( 1 ) and 3‐O‐β‐D ‐xylopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl‐28‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→4)‐[β‐D ‐galactopyranosyl‐(1→2)]‐α‐L ‐rhamnopyranosyl‐(1→2)‐{6‐O‐[2‐hydroxymethyl‐6‐methyl‐6(S)‐hydroxy‐2‐trans‐2,7‐octadienoyl]}‐β‐D ‐glucopyranosylechinocystic acid ( 2 ). The complete ¹H and ¹³C assignments of saponins 1 and 2 were achieved on the basis of 2D NMR spectra including HMQC‐TOCSY, TOCSY, ¹H–¹H COSY, HMBC, ROESY and HMQC spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

Gas phase isomeric differentiation of oleanolic and ursolic acids associated with heptakis‐(2,6‐di‐O‐methyl)‐β‐cyclodextrin by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

Oleanolic acid (OA) and ursolic acid (UA) are isomeric triterpenoid compounds with similar pharmaceutical properties. Usually, modern chromatographic and electrophoretic methods are widely utilized to differentiate these two compounds. Compared with mass spectrometric (MS) methods, these modern separation methods are both time‐ and sample‐consuming. Herein, we present a new method for structural differentiation of OA and UA by Fourier transform ion cyclotron resonance mass spectrometry (FT‐ICR MS) with the association of heptakis‐(2,6‐di‐O‐methyl)‐β‐cyclodextrin (DM‐β‐CD). Exact MS and tandem MS (MS/MS) data showed that there is no perceptible difference between OA and UA, as well as their β‐cyclodextrin and γ‐cyclodextrin complexes. However, there is a remarkable difference in MS/MS spectra of DM‐β‐CD complexes of OA and UA. The peak corresponding to the neutral loss of a formic acid and a water molecule could only be observed in the MS/MS spectrum of the complex of DM‐β‐CD : OA. Molecular modeling calculations were also employed to further investigate the structural differences of DM‐β‐CD : OA and DM‐β‐CD : UA complexes. Therefore, by employing DM‐β‐CD as a reference reagent, OA and UA could be differentiated with purely MS method. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis of benzyl O-(2,3,3'-tri-O-acetyl-β-D-apiofuranosyl)-(1→3)-2,4-di-O-benzoyl-α-D-xylopyranoside and its X-ray structure

The protected apiose-containing disaccharide, benzyl O-(2,3, 3'-tri-O-acetyl-β-D-apiofuranosyl)-( 1→3)-2, 4-di-O-benzoyl-α-D-xylopyranoside, was synthesized and its X-ray structure provided.     

Synthesis of 2‐(sulfamoylphenyl)‐4′‐(iminoaryl/hetroaryl)‐4‐(4′′‐hydroxyphenyl)‐thiazoles and their O‐glucosides

In continuation of our work, we synthesized 2‐(sulfamoylphenyl)‐4′‐amino‐4‐(4″‐hydroxyphenyl)‐thiazole ( 3a ), which were reacted with various (aryl/hetroaryl) aldehyde to form 2‐(sulfamoylphenyl)‐4′‐(iminoaryl/hetroaryl)‐4‐(4″‐hydroxyphenyl)‐thiazoles ( 4a , 4b , 4c , 4d , 4e , 4f ). Glucosylation of compounds ( 4a , 4b , 4c , 4d , 4e , 4f ) have been done by using acetobromoglucose as a glucosyl donor to afford 2‐(sulfamoylphenyl)‐4′‐(iminoaryl/hetroaryl)‐4‐(2,3,4,6‐tetra‐O‐acetyl‐4″‐O‐β‐D ‐glucosidoxyphenyl)‐thiazoles ( 5a , 5b , 5c , 5d , 5e , 5f ), further on deacetylation to produce 2‐(sulfamoylphenyl)‐4′‐(iminoaryl/hetroaryl)‐4‐(4″‐O‐β‐D ‐glucosidoxyphenyl)‐thiazoles ( 6a , 6b , 6c , 6d , 6e , 6f ). The compounds are confirmed by FTIR, ¹H‐NMR, ¹³C‐NMR, and ES‐Mass spectral analysis. J. Heterocyclic Chem., (2011).     

Veronicafolin－β-环糊精的物化表征及Veronicafolin－羟丙基-β-环糊精包合物溶解性的增强

用氢谱、红外光谱、X-射线粉末衍射、热分析、元素分析等测试方法研究了Veronicafolin (3,5,4′-三羟基-6,7,3′-三甲氧基黄酮) 和β-环糊精 (β-CD) 的固体包合物的谱学特征。元素分析结果显示形成Veronicafolin-β-CD·20H2O包合物，其中C：39.58%, H: 5.75%，表明包合物中主客体比为1∶1。该包合类型属于A_L-型。通过紫外-可见分光光度法研究了在羟丙基-β-环糊精（HP-β-CD）的存在下Veronicafolin的相溶解度曲线，测得校正曲线为y = 24148x + 0.0075 (r=0.9999)，相溶解曲线为y=0.4738x-2.0×10^-7 (r=0.9490)，包结平衡常数Ks为4.5×10⁶mol-1。HP-β-CD提高了黄酮醇Veronicafolin的溶解度。