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Isomaltomegalosaccharide (IMS) is a long chimeric glucosaccharide composed of α-(1 → 6)- and α-(1 → 4)-linked segments at nonreducing and reducing ends, respectively; the hydrophilicity and hydrophobicity of these segments are expected to lead to bifunctionality. We enzymatically synthesized IMS with average degrees of polymerization (DPs) of 15.8, 19.3, and 23.5, where α-(1 → 4)-segments had DPs of 3, 6, and 9, respectively. IMS exhibited considerably higher water solubility than maltodextrin because of the α-(1 → 6)-segment and an identical resistance to thermal degradation as short dextran. Interaction of IMS with a fluorescent probe of 2-p-toluidinylnaphthalene-6-sulfonate demonstrated that IMS was more hydrophobic than maltodextrin, where the degree of hydrophobicity increased as DP of α-(1 → 4)-segment increased (9 6 3). Fluorescent pyrene-estimating polarity of IMS was found to be similar to that of methanol or 1-butanol. The bifunctional IMS enhanced the water solubility of quercetin-3-O-glucoside and quercetin: the solubilization of less-soluble bioactive substances is beneficial in carbohydrate industry.

Dextran dextrinase (DDase) catalyzes formation of the polysaccharide dextran from maltodextrin. During the synthesis of dextran, DDase also generates the beneficial material isomaltomegalosaccharide (IMS). The term megalosaccharide is used for a saccharide having DP=10-100 or 10-200 (DP, degree of polymerization). IMS is a chimeric glucosaccharide comprising alpha-(1 -> 6)- and alpha-(1 -> 4)-linked portions at the nonreducing and reducing ends, respectively, in which the alpha-(1 -> 4)-glucosyl portion originates from maltodextrin of the substrate. In this study, IMS was produced by a practical approach using extracellular DDase (DDext) or cell surface DDase (DDsur) of Gluconobacter oxydans ATCC 11894. DDsur was the original form, so we prepared DDext via secretion from intact cells by incubating with 0.5% G6/G7 (maltohexaose/maltoheptaose); this was followed by generation of IMS from various concentrations of G6/G7 substrate at different temperatures for 96 h. However, IMS synthesis by DDext was limited by insufficient formation of alpha-(1 -> 6)-glucosidic linkages, suggesting that DDase also catalyzes elongation of alpha-(1 -> 4)-glucosyl chain. For production of IMS using DDsur, intact cells bearing DDsur were directly incubated with 20% G6/G7 at 45 degrees C by optimizing conditions such as cell concentration and agitation efficiency, which resulted in generation of IMS (average DP =14.7) with 61% alpha-(1 -> 6)-glucosyl content in 51% yield. Increases in substrate concentration and agitation efficiency were found to decrease dextran formation and increase IMS production, which improved the reaction conditions for DDext. Under modified conditions (20% G6/G7, agitation speed of 100 rpm at 45 degrees C), DDext produced IMS (average DP =14.5) with 65% alpha-(1 -> 6)-glucosyl content in a good yield of 87%.

Inclusion complex of the per-D-mannose-grafted-β-cyclodextrin (Man-CD), which synthesized by azide-alkyne “click reaction”, with Ibuprofen sodium salt (IBUNa) was investigated by NMR spectroscopy. NMR titration showed its 1:1 stoichiometry and 3.3-fold higher binding constant than parent β-cyclodextrin (β-CD). Furthermore, the possible orientations of the guest molecules were deduced by 2D NOESY and ROESY experiments.

Stereo- and regioselective formation of glycosidic linkages is a challenging topic in oligosaccharide syntheses. The stereoselective construction of 1,2-trans-glycosides generally involves neighboring group participation, which is less successful when synthesizing β-1,3-linked oligosaccharides. The combined steric effect of a 2-O-substituent and an aglycon moiety in acceptors increases the efficiency of glycosylation via neighboring group participation. This steric effect was reduced by using vicinal polyol acceptors and was demonstrated in the synthesis of 1,3-linked branched oligosaccharides.

A linear and non-crosslinked polymer, EDTA-linked chitosan (ED-ch), was synthesized by N-acylation of chitosan with EDTA (ethylenediaminetetraacetic acid) monoanhydride under acidic to slightly basic aqueous conditions. The degree of substitution (D.S.) of EDTA residues in the product was changeable depending on the stoichiometry of the acylation reagent, and the structure was confirmed by elemental analysis, FT-IR, 1H and 13C NMR spectroscopy. The newly introduced functional group in ED-ch provided properties such as being a strong chelating reagent and an amphoteric polyelectrolyte. It was found that ED-ch had good water solubility in both acidic and basic regions and precipitated in a narrow pH region. Applicability of ED-ch to the removal of heavy metal ions by flocculation was proven by a model experiment using 10 ppm Cu(II) solution. A simple procedure, mixing ED-ch with D.S. 41% and 70%, and subsequent pH adjustment (4.5 and 2.5) and centrifugal separation of the flocs formed, was shown to remove Cu(II) almost completely from aqueous solution. The residual Cu(II) concentration after these flocculation/separation process with ED-ch reached 0.03 ppm.

Intermolecular interaction of linear-type α-(1 → 6)-glucosyl megalosaccharide rich (L-IMS) and water-insoluble anionic ethyl red was firstly characterized in a comparison with inclusion complexation by cyclodextrins (CDs) to overcome the problem of poor solubility and bioavailability. Phase solubility studies indicated an enhancement of 3- and 9-fold over the solubility in water upon the presence of L-IMS and β-CD, respectively. (1)H NMR and circular dichrosim spectra revealed the dye forms consisted of 1:1 stoichiometric inclusion complex within the β-CD cavity, whereas they exhibited non-specific hydrophobic interaction, identified by solvent polarity changes, with L-IMS. The inclusion complex delivered by β-CD showed an uncompetitive inhibitory-type effect to azoreductase, particularly with high water content that did not promote dye liberation. Addition of the solid dye dispersed into coupled-enzyme reaction system supplied by L-IMS as the dye solubilizer provided usual degradation rate. The dye intermission in series exhibited successful removal with at least 5 cycles was economically feasible.

This study reports the characterization of the ability of Dermacoccus spp. isolated from the deepest point of the world's oceans for azo dye decolorization. A detailed investigation of Dermacoccus abyssi MT1.1(T) with respect to the azoreductase activity and enzymatic mechanism as well as the potential role of the bacterial strain for biocleaning of industrial dye baths is reported. Resting cells with oxygen-insensitive azoreductase resulted in the rapid decolorization of the polysulfonated dye Brilliant Black BN (BBN) which is a common food colorant. The highest specific decolorization rate (vs) was found at 50 °C with a moderately thermal tolerance for over 1 h. Kinetic analysis showed the high rates and strong affinity of the enzymatic system for the dye with a Vmax = 137 mg/g cell/h and a Km = 19 mg/L. The degradation of BBN produces an initial orange intermediate, 8-amino-5-((4-sulfonatophenyl)diazenyl)naphthalene-2-sulfonic acid, identified by mass spectrometry which is later converted to 4-aminobenzene sulfonic acid. Nearly 80% of the maximum vs is possible achieved in resting cell treatment with the salinity increased up to 5.0% NaCl in reaction media. Therefore, this bacterial system has potential for dye decolorization bioprocesses occurring at high temperature and salt concentrations e.g. for cleaning dye-containing saline wastewaters.

Asexual spores of the filamentous fungus Rhizopus arrhizus were used as the resting biomass as they tolerate chitosan gelling for mycelia growing in chitosan beads. Biosorption of lead using the dead detergent pre-treated chitosan-immobilised and grown fungal beads was performed with initial lead (II) nitrate concentrations ranging from 9.02 to 281.65 mg/L. The adsorption data were best correlated with equilibrium adsorption isotherms in the order Redlich–Peterson, Langmuir, Freundlich and Fritz–Schlunder by non-linear regression. The biosorption kinetic model of pseudo second-order (R 2 > 0.99) fitted better than pseudo first-order and modified pseudo first-order models. Among the four pseudo second-order kinetic models, the Blanchard model was the best fit for the experimental biosorption data. The rate-limiting step of biosorption of lead was shown to be intraparticle diffusion controlled according to Weber and Morris model fitting. The beads could be regenerated using 1 M nitric acid solution. This illustrated the good performance of the beads for regenerated sorption/desorption at least five cycles.

The nonylphenol (NP) biosorption and desorption potential for fungal biomass used under batch conditions was investigated using kinetics and isotherm models. Fungal biomass of Rhizopus arrhizus TISTR 3610 exhibited preferential uptake of NP, an endocrine disrupting chemicals. Sporangiospores, asexual spores, were immobilised in chitosan beads. The biosorption data of NP on the moist heat inactivated R. arrhizus –chitosan beads were analyzed using four popular adsorption isotherms and, by using non-linear least-regression with the solver add-in in Microsoft Excel, correlated in order with the Fritz–Schluender > Redlich–Peterson > Freundlich > Langmuir isotherms. The pseudo first-order kinetics was found to have the best fit with the experimental data. The diffusivity of NP in the R. arrhizus –chitosan beads was calculated using the shrinking core model, and the diffusivity values were in the ranges of 2.3736 × 10 −4 –1.8950 × 10 −4 cm 2 s −1 . Desorption to recover the adsorbed NP from the beads was performed in methanol and was best described using a pseudo second-order kinetic model.

LETTER, Oligosaccharide containing macrolides of resin glycosides were effectively constructed by MeOTf promoted intramolecular glycosylation of dodecyl thioglycosyl donors. Synthesis of a key disaccharide intermediate of tricolorin A and total synthesis of tricolorin F were successfully achieved by this approach.

Fully acetylated dodecyl thioglycosides were found to be useful as glycosyl donors by activation with 1-benzenesulfinyl piperidine (BSP) and triflic anhydride (Tf 2 O) at −78 °C. The glycosyl acceptor was added to the reaction mixture at the same temperature to furnish various disaccharide, including the protected Lewis a (Le a ) trisaccharide, in good yields.

The first total synthesis of a unique tetrasaccharide repeating unit of lipopolysaccharide from Salmonella enteritidis has been accomplished by assembly of dodecyl thioglycosides. The crucial key steps were preparation of a rare branched dideoxy sugar, d -tyvelose (3,6-dideoxy- d -arabino- d -hexose) and sequential regioselective glycosylation at 2,3-positions of a central d -mannose residue 5 with d -tyvelose 6 and d -galactose donors 7.

Calcium alginate beads covalently linked with alpha-cyclodextrin (alpha-CD-alginate beads) were prepared and examined for their ability to serve as a supporting matrix for bacterial degradation of nonylphenol, an endocrine disruptor. Column chromatographic experiment using alpha-CD-alginate beads with diameter of 657+/-82 microm and with degree of CD substitution of 0.16 showed a strong affinity for nonylphenol adsorption. Although addition of alpha-CD (2.7-27 mM) to the culture broth of Sphingomonas cloacae retarded nonylphenol degradation, the immobilized bacteria on the CD-alginate beads were effective for the degradation. Batch degradation tests using the immobilized bacteria on alpha-CD-alginate-beads showed 46% nonylphenol recovery after 10-day incubation at 25+/-2 degrees C, and the recovery reached to about 17% when wide and shallow incubation tubes were used to facilitate uptake of the viscous liquid of nonylphenol on the surface of the medium. Scanning electron microscopic photographs revealed that multiplicated bacteria was present both on the surface and inside the beads and the matrix of CD-alginate was stable and suitable during 10-day incubation.

O-Linked glycosylation of serine/threonine residues is a posttranslational modification of proteins and is essential for protein recognition and lipid functions on cell surfaces and within cells. The characterization of differently structured O-linked glycans (O-glycans) is particularly challenging because there is no known endoglycosidase for such groups. Therefore, chemical digestion approaches have been widely used; however, it is sometimes difficult to suppress unwanted side reactions. Recently, we reported a novel O-glycomics procedure using β-elimination in the presence of pyrazolone analogues (BEP). In the present study, we describe a microwave (MW)-assisted BEP procedure for rapid and quantitative O-glycomic analysis. Following optimization of the reaction conditions, the MW-assisted BEP reaction substantially improved the recovery of total O-glycans from model glycoproteins (PSM) and the reaction time was reduced from 16 to 2 h. Combined with sequential solid-phase extractions, this MW-assisted BEP procedure enabled O-glycomic analyses of various biological samples.

Published in Macromolecular Bioscience, 2006, Wiiley-VCH Verlag GmbH & Co. KGaA, Weinheim, A single-stranded DNA readily extracted from industrial discarded salmon milt, was used to prepare hydrogels and complex gels by cross-linking with gelatin and κ-carrageenan, for the oral delivery of probiotic bacteria. The complex gels showed a higher protective capability over the hydrogels for approximately one log scale. However, the hydrogels were more stable during 4°C storage. The Lactobacillus and Lactococcus due to protection of the hydrogels could better tolerate to acid than the Bifidobacterium. Furthermore, food-graded hydrogels were prepared and optimized to a similar protective capability for future applications.

A novel approach to natural β-hydroxy-γ-lactone 2 from 2,5-anhydro- d -mannitol ( 1 ) is described. The key reactions in this synthesis include stereoselective methylation of aldehyde 3 with lithium dimethylcuprate, an intramolecular radical cyclization of seleno carbonate 11 and an intermolecular cross-metathesis of 3-allyl-4-hydroxy-γ-lactone 16 with 1-tridecene.

An efficient and practical method for the large-scale synthesis of an anti-inflammatory glycocluster having seven sialyl Lewis X (SLeX) residues was established on the basis of chemical and enzymatic strategy from β-cyclodextrin (β-CD) as a key starting scaffold material. A key intermediate, β-CD derivative having seven N-acetyl- d -glucosamine (GlcNAc) residues [(GlcNAc)7CD], was prepared by a coupling reaction with heptakis 6-deoxy-6-iodo-β-cyclodextrin and sodium thiolate containing a GlcNAc residue. Subsequent sugar elongation reactions of (GlcNAc)7CD proceeded smoothly by means of β-1,4-galactosyltransferase, α-2,3-sialyltransferase, and α-1,3-fucosyltransferase V in the presence of the corresponding sugar nucleotides (UDP-Gal, CMP-Neu5Ac, and GDP-Fuc) and allowed to give a mono-dispersed glycodendrimer (Mw=7924.5, calcd for C301H490N21O196S7Na7; MALDI-TOF MS, m/z 7946 [M+Na]+) that completely substituted with seven SLeX branches at C-6 positions in excellent overall yield (74%, 3 steps). Hyper-branched glycodendrimer, (SLeX)7CD, exhibited highly amplified inhibitory effect on the interaction of E-selectin with SLeXn-BSA immobilized on the sensor chip by means of surface plasmon resonance method.

A novel chitosan-based polymeric surfactant, DG-chitosan, was prepared via reductive N-alkylation of chitosan with 3-O-dodecyl- d -glucose in acetate buffer (pH 4.3, 0.1 M)-methanol in the presence of sodium cyanoborohydride (NaBH3CN). DG-chitosan was swelling in water, partly dissolvable in pyridine and DMF, and completely soluble in 0.1% aqueous acetic acid. 1H and 13C NMR spectroscopic analyses in 2% acetic acid-d4-methanol-d4 together with elemental analysis showed the degree of substitution was 27%. Formation of polymeric micelles was observed by use of pyrene as a fluorescent probe, and the critical aggregation concentration (CAC) of DG-chitosan was marked equal to 28.1 mg/L.

An efficient synthesis of a useful thioglycosyl donor 2 was accomplished directly from known peracetylated sialic acid methyl ester and 1-dodecanethiol (lauryl mercaptan) in the presence of BF3–OEt2. The reactivities of the lauryl glycosides for glycosidation by means of TMSOTf as a convenient promoter were investigated, and the lauryl thioglycoside showed satisfactory activities. Further transformation of the lauryl glycoside was also attempted to give a 5-azide analogue 14 of the sialic acid, which was also reacted with a secondary alcohol in the presence of TMSOTf to give known glycoside 15 in high yield.

beta(2)-glycoprotein I (beta(2)-GPI) is a major antigen for antiphospholipid antibodies (Abs, aPL) present in patients with antiphospholipid syndrome (APS). We recently reported (I. Lipid Res., 42: 697, 200 1; J Lipid Res., 43: 1486, 2002) that beta(2)-GPI specifically binds to Cu2+-oxidized LDL (oxLDL) and that the beta(2)-GPI ligands are omega-carboxylated 7-ketocholesteryl esters. In the present study, we demonstrate that oxLDL forms stable and nondissociable complexes with beta(2)-GPI in serum, and that high serum levels of the complexes are associated with arterial thrombosis in APS. A conjugated ketone function at the 7-position of cholesterol as well as the omega-carboxyl function of the beta(2)-GPI ligands was necessary for beta(2)-GPI binding. The ligand-mediated noncovalent interaction of beta(2)-GPI and oxLDL undergoes a temperature- and time-dependent conversion to much more stable but readily dissociable complexes in vitro at neutral pH. In contrast, stable and nondissociable beta(2)-GPI-oxLDL complexes were frequently detected in sera from patients with APS and/or systemic lupus erythematodes. Both the presence Of beta(2)-GPI-oxLDL complexes and IgG Abs recognizing these complexes were strongly associated with arterial thrombosis. Further, these same Abs correlated with IgG immune complexes containing beta(2)-GPI or LDL.jlr Thus, the beta(2)-GPI-oxLDL complexes acting as an autoantigen are closely associated with autoimmune-mediated atherogenesis.

A new method for the surface modification of nonporous glass beads (average diameter, 6 μm), which characterized by formation of a 1,3-thiazolidine ring between l -cysteine linkers on the glass bead and reducing ends of chitosan, has been developed. γ-Aminopropyltriethoxysilane (APES)-treated glass bead was first subjected to condensation with an l -cysteine derivative, l -4-carboxy-3-formyl-2,2-dimethylthiazolidine (CFMT), in the presence of water-soluble carbodiimide hydrochloride (WSC) and HOBt. After deprotection by diluted hydrochloric acid, the glass beads with activated cysteine linkers on the surface were treated with reducing chitosan in aqueous acetic acid solution at room temperature. The maximum content of chitosan immobilized on the glass beads estimated by acid-hydrolysis and subsequent glucosamine analysis by Svennerholm method after was 0.73% (w/w). This was obtained by using chitosan having an average molecular weight of 14 kD. Model reactions of the cysteine derivatives with reducing chitosan were also performed and the product was examined by IR and NMR spectroscopy to verify the linkage between cysteine and chitosan.

beta(2)-Glycoprotein I (beta(2)-GPI) is a major antigen for anticardiolipin antibodies (aCL, Abs) present in patients with antiphospholipid syndrome. We recently reported that beta(2)-GPI specifically binds to oxidized LDL (oxLDL) and that the beta(2)-GPI's major ligand, oxLig-1 is 7-ketocholesteryl-9-carboxynonanoate (Kobayashi, K., E. Matsuura, Q. P. Liu, J. Furukawa, K. Kaihara, J. Inagaki, T. Atsumi, N. Sakairi, T. Yasuda, D. R. Voelker, and T. Koike. 2001. A specific ligand for beta(2)-glycoprotein I mediates autoantibody-dependent uptake of oxidized low density lipoprotein by macrophages. J. Lipid Res. 42: 697-709). In the present study, we demonstrate that omega-carboxylated 7-ketocholesteryl esters are critical for beta(2)-GPI binding. A positive ion mass spectrum of a novel ligand, designated oxLig-2, showed fragmented ions at m/z 383 and 441 in the presence of acetone, which share features of oxLig-1 and 7-ketocholesterol. In the negative ion mode, ions at m/z 627, 625, and 243 were observed. oxLig-2 was most likely 7-ketocholesteryl-12-carboxy (keto) dodecanoate. These ligands were recognized by beta(2)-GPI. Liposome binding to macrophages was significantly increased depending on the ligand's concentration, in the presence of beta(2)-GPI and an anti-beta(2)-GPI Ab. Synthesized variant, 7-ketocholesteryl-13-carboxytridecanoate (13-COOH-7KC), also showed a significant interaction with beta(2)-GPI and a similar binding profile with macrophages. Methylation of the carboxyl function diminished all of the specific ligand interactions with beta(2)-GPI. Thus, omega-carboxyl variants of 7-ketocholesteryl esters can mediate anti-beta(2)-GPI Ab-dependent uptake of oxLDL by macrophages, and autoimmune atherogenesis linked to beta(2)-GPI interaction with oxLDL.

A new hybrid material that adsorbs transition metal ions was prepared by immobilizing chitosan on the surface of nonporous glass beads. The glass beads, prepared by etching in aqueous NaOH at 100°C, were first reacted with γ-aminopropyltriethoxysilane (APES) to introduce amino groups on the surface. Subsequently, the resulting aminated beads were treated with glutaraldehyde at 25°C to change the amino groups into aldehyde groups. Finally, chitosan of average molecular weight 40,000 was introduced via the aldehyde groups through a Schiff's reaction. After complete acid-hydrolysis of the immobilized chitosan, the Svennerholm method for glucosamine analysis showed that 0.3% (w/w) chitosan had been successfully introduced on the glass beads. Atomic absorption spectroscopic analysis of eluants of a column of the chitosan-modified glass beads showed that metal ions such as Cu2+, Ag+, Pb2+, Fe3+, and Cd2+ were more than 90% entrapped on a column of beads prepared in this manner.

The 6-O-mesyl derivative of phenyl 1-thio-β- d -glucopyranoside was prepared from d -glucose as a synthetic equivalent of a 6-deoxy-hexosyl donor. Racemic methyl 11-hydroxytetradecanoate (methyl convolvulinolate) was synthesized by Grignard reaction of propylmagnesium bromide with 10-undecenal followed by hydroboration. Both intermediates were coupled by NIS–TfOH-promoted glycosidation to give a mixture of two diasteromeric glucopyranosides, which were separated on a preparative scale by medium pressure chromatography. One of the products was identified as having the natural (S)-configuration by comparison of its 1H NMR spectrum with an authentic sample prepared from the corresponding chiral hydroxyfatty acid.

Immobilization of double-stranded DNA onto nonwoven cellulose fabric by UV irradiation and utilization of DNA-immobilized cloth were examined. The immobilized DNA was found to be stable in water, with the maximum amount of fabric-immobilized DNA being approximately 20 mg/g of nonwoven fabric. The DNA-immobilized cloth could effectively accumulate endocrine disruptors and harmful DNA intercalating pollutants, such as dibenzo-p-dioxin, dibenzofuran, biphenyl, benzo[a]pyrene and ethidium bromide. Additionally, DNA-immobilized cloth was found to bind metal ions, such as Ag+, Cu2+, and Zn2+. The maximum amounts of bound Ag+, Cu2+, and Zn2+ onto DNA-immobilized cloth (1 g) were approximately 5, 2, and 1 mg, respectively. DNA-immobilized cloth containing Ag+ showed antibacterial activity against Escherichia coli and Staphylococcus aureus. DNA-immobilized cloth without metal ion and with Cu2+ or Zn2+ did not show antibacterial activity. These results suggest that immobilized DNA imparts useful functionality to cloth. DNA-immobilized cloth prepared by UV irradiation has potential to serve as a useful biomaterial for medical, engineering, and environmental application.

beta(2)-Glycoprotein I (beta(2)-GPI) is a major antigen for antiphospholipid antibodies (Abs) present in patients with the antiphospholipid syndrome (APS). We previously reported that beta(2)-GPI specifically binds to oxidized low density lipoprotein (oxLDL), but not to native low density lipoprotein (LDL). In the present study, a ligand specific for beta(2)-GPI, oxLig-1, was purified from the extracted lipids of oxLDL. The structure of oxLig-1 was shown to be identical to that of synthesized 7-ketocholesteryl-9-carboxynonanoate by mass spectroscopy and nuclear magnetic resonance analyses. Both purified and synthesized oxLig-1 were recognized by beta(2)-GPI and subsequently by anti-beta(2)-GPI auto-Abs, either in enzyme-linked immunosorbent assay (ELISA) or in ligand blot analysis. Binding of liposomes containing oxLig-1 (oxLig-1-liposomes) to mouse macrophages, J774A.1 cells, was relatively low, as compared with that of phosphatidylserine (PS)-liposomes. In contrast, binding of oxLig-1-liposomes was enhanced more than 10-fold in the presence of both beta(2)-GPI and an anti-beta(2)-GPI auto-Ab (WB-CAL-1), derived from (NZW x BXSB) F1 mouse, an animal APS model. Anti-beta(2)-GPI auto-Abs derived from APS patients with episodes of arterial thrombosis were detected in ELISA, using a solid phase oxLig-1 complexed with beta(2)-GPI. We suggest that autoimmune atherogenesis linked to beta(2)-GPI interaction with oxLDL and Abs may be present in APS.

A new cotton fiber with a chitosan coating (CCCF) was prepared by the oxidation of a cotton thread with potassium periodate at 60°C in water and subsequent treatment with a solution of chitosan in aqueous acetic acid. Infrared spectra of the CCCF suggested the formation of Schiff's base between the chitosan and the oxidized cellulose. Kjeldahl nitrogen analysis of the CCCF showed that the maximum percentage of chitosan introduced into the cotton fiber was 1.58% (w/w). Treatment of the fiber with 2′,7′-difluoro fluorescein (an amino group-specific probe) followed by fluorescent microscopic analysis revealed that the modification with chitosan occurred on the surface of the cotton fiber. Scanning electron microscopy (SEM) photographs showed that the surface of the CCCF was slightly changed after the series reaction. However, the mechanical strength of the cotton thread, which was oxidized by the potassium periodide solution at a concentration of less than 2.0 mg/ml, was found to be almost the same as the original cotton thread. Furthermore, a model experiment for the controlled release of the drug was preformed using shikonin, a component of a Chinese medicine, suggested potential usefulness of the CCCF as a supporter for the controlled release of drugs.

樹脂配糖体は主としてユウガオ科植物より単離された糖脂質である。これらはかつて伝統的民間治療薬の主要成分として研究されていたが、最近では癌細胞に対する細胞毒性、抗菌活性、植物生長の制御効果などのユニークな生物活性が報告されている。これら生理活性を有する樹脂配糖体の多くはアグリコン部の脂肪酸のカルボキシル基と糖水酸基が分子内エステル化したマクロライド構造を有している。これらの注目すべき分子構造と生化学的な特徴より、樹脂配糖体の全合成に関する研究が報告されるようになった。本稿では樹脂配糖体の化学的合成における最近の進歩について紹介する。

Calonyctin A2, a tetrasaccharidic glycolipid having a 22-membered macrolidic structure, has been synthesized by the assembly of three 6-deoxygenated thioglycoside intermediates. The short-step synthesis was achieved by preparation of the most complicated b–c disaccharide unit from phenyl 2,2′:4,6:4′,6′-tri-O-benzylidene-1-thio-β- d -laminaribioside without any glycosidation reaction and by regioselective macrolactonization.

Highly porous beads having an ability to form inclusion complexes with specific substrates have been synthesized and preliminary experiments for the application to adsorbent for affinity column chromatography and controlled release were carried out. Water-insoluble chitosan beads were synthesized by adding an aqueous acetic acid solution of chitosan into ethanolic aqueous sodium hydroxide and subsequent crosslinking with hexamethylene diisocyanate in N, N-dimethylformamide. The resulting beads were further treated with 2-O-formylmethyl-α-cyclodextrin in the presence of sodium cyanoborohydride in acetate buffer at pH 4.4, giving the cyclodextrin-linked chitosan beads. Their inclusion ability was examined by the use of p-nitrophenol and its analogue as model compounds.

An amylose-like α-(1,4)-glucan was synthesized by polycondensation and subsequent deprotection of a partially benzylated phenyl 1-thio-β-maltooctaoside having a sole hydroxyl group at the non-reducing end. The key octasaccharide monomer 6 was prepared by means of a single-site acetolytic reaction of fully acetylated γ-cyclodextrin and several subsequent chemical manipulations at its reducing and non-reducing ends. On activation with methyl triflate, the polycondensation of 6 was found to proceed in diethyl ether through intermolecular glycosidation. The molecular weight of the product obtained by preparative GPC on Sephadex LH-60 was 10 000–18 000. Removal of the O-benzyl groups under Birch reaction gave α-(1,4)-glucan, the stereoregularity of which was confirmed by 1H and 13C NMR spectroscopy.

Biological reconstruction of water-soluble carboxymethylated cellulose (CMC; D.S. =0.47) has been achieved by culturing Acetobacter xylinum in medium containing CMC and d -glucose to give a novel hetero-polysaccharide having a carboxymethyl function. The novel extracellular polysaccharide, carboxymethylated-bacterial cellulose (CM-BC), had an ion exchange ability with enhanced specific adsorption for lead and uranyl ions compared to the original CMC and bacterial cellulose. The contribution of the hydroxy group at C-2 was confirmed by applying carboxymethylated chitin, which possesses acetamido group at C-2 of the glucose residue, as the carbon source of the incubation.

A (+)-10-Camphorsulfonic acid-catalysed acetal exchange reaction of phenyl 1-thio-β-laminaribioside using 3.5 molar equivalents of α,α-dimethoxytoluene gave a tris(benzylidene acetal), which was isolated and characterized as phenyl 3′-O-acetyl-2,2′ : 4,6 : 4′,6′-tri-O-benzylidene-1-thio-β-laminaribioside, and the corresponding 3′-O-benzyl derivative 6. Upon a treatment with pyridinium p-toluenesulfonate, the interglycosidic 2,2′-acetal in 6 underwent selective cleavage to give the 2,2′-diol. Additionally, a reductive ring-opening reaction of 6 with lithium aluminium hydride/anhydrous aluminium chloride, followed by O-acetylation, gave the 2,6,6′-O-acetyl-4,2′,3′,4′-tetra-O-benzyl derivative in 73% yield. A different regioselectivity was observed in the reduction of 6 with borane-trimethylamine adduct/anhydrous aluminium chloride or sodium cyanotrihydroborate/methanesulfonic acid, giving the corresponding 2,4,4′-triol as the major product.

Continuous filamentation of bacterial cellulose (BC) was successfully achieved by using shallow pan for the incubation to regulate thickness of the BC gel produced by Acetobacter xylinum . The BC filament was harvested and prepared directly by picking up BC pellicles, the thin BC gel, and winding slowly from the surface of the culture medium passed through a preliminary bactericidal washing bath. The X-ray diffraction analysis and scanning electron microscopic observation of the BC filament thus obtained showed that the filament was smooth and the fairly good orientation of BC molecules. The average tensile strength was 4.4 g denier −1 for the filament prepared by hot alkaline treatment and subsequent washing with distilled water and dried under tension (Filament W): 3.4 g denier −1 for washing with 10% aqueous ethylene glycol after alkaline treatment followed by drying under tension (Filament E) and 2.4 g denier −1 for the treatment with 10% ethylene glycol after normal water-washing followed by drying under tension.

The continuous Filature of bacterial cellulose has been achieved directly from culture medium using shallow culture pan newly designed. A remarkable progress of fiber properties was observed comparing with regenerated cellulosic filaments on the filament of bacterial cellulose dependently on the rinsing process with water or ethylene glycol. The progress of fiber properties was also shown on the filament of N-acetylglucosamine(GlcNAc) incorporated bacterial cellulose probably due to enforcement of fiber interactions. A copolymer of carboxymethyl-glucose (CM-Glc) and glucose has been achieved successfully to increase the adsorption capacity for lead ion comparing with original carboxymethyl cellulose (CMC).

酢酸菌が菌体外に生産する多糖バクテリアセルロースの培養法の違いによる生産量および物理的性質の変化について検討を行った. 従来からの静置培養に比較して, 回転通気培養や連続巻き上げ皿培養の方がセルロースの収量が向上することがわかった. 特に後者では産生された多糖を直接紡糸することが可能で精製操作を簡略化できる上, 得られた糸はヤング率など力学的強度にも優れていた. 広角X線回折の結果からも優れた分子配向が確認された.

イカ由来β-キチンのN, N-ジメチルホルムアミド (DMF) -尿素溶媒中オルトリン酸との反応により, 高収率でリン酸化キチンを合成できた. 本反応はキチンの低分子量化を伴わず, リン酸基の導入率は反応溶媒DMFと尿素の比率で制御可能であった. 生成物のリン酸基置換度は0.25～1.4のものが得られ, 置換度0.25以上の誘導体は水溶性であった. 水溶性リン酸化キチンはカルシウムイオンを吸着して, 不溶性のアモルファス, ゲル状キチン誘導体が得られた. また牛血漿を用いた血液凝固試験でリン酸化キチンは凝固の促進作用を有することが示された.

Reductive alkylation of the amino group of chitosan with β-cyclodextrin (CD) aldehyde derivatives, i.e., 6-deoxy-6-(4-oxobutyramido)-β-CD and 6-oxo-β-CD, gave two β-CD-linked chitosan derivatives with C4 (4-butylamido) and C0 linking arms, respectively. Degree of substitution (D.S.) of both C4-β-CD and C0-β-CD linked chitosan was controlled by the ratio of starting materials. The structures of the products were confirmed by 1 H and 13 C NMR and FT-IR spectra. Their inclusion properties of C4-β-CD (D.S. 18%) and C0-β-CD linked chitosan (D.S. 17%) with a fluorescent probe, 6-( p -toluidino)-2-napthalene-6-sulfonate (TNS) were investigated in acetate buffer (pH 4.3) at 25 °C. Continuous variation of Job's method revealed that the stoichiometry of inclusion complex of C4-β-CD linked chitosan-TNS was 1:1, whereas that of C0-β-CD linked chitosan was not 1:1. The stability constant of C4-β-CD linked chitosan determined by Benesi–Hildebrand plot was 2.3 × 10 3 M −1 . These results suggested that length of the linking arms between CD and chitosan is influenced on their inclusion property.

Nucleoplasmin was isolated from Xenopus laevis eggs and purified by an improved method using an open column. Its conformation was investigated spectrophotometrically by UV, CD and fluorescence. It was shown that alpha-helix content of nucleoplasmin was 30-40%, and one of the two tryptophan residues in nucleoplasmin located in the hydrophobic surroundings and the other in the relatively hydrophilic surroundings. The isolated nucleoplasmin was found to decondense sperm nuclei of salmon also, suggesting a possibility of the existence of nucleoplasmin-like protein in fish as well. Collapse of the protamine (salmine)-DNA complex as a simple model for fish sperm nuclei by nucleoplasmin was directly observed by measuring OD320 of aqueous protamine-DNA mixtures. This is a molecular level observation for the removal of protamine from DNA-protamine complex.