ω-Carboxyl variants of 7-ketocholesteryl esters are ligands for β2-glycoprotein I and mediate antibody-dependent uptake of oxidized LDL by macrophages

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. Welker, 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-carboxytxidecanoate (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

Water soluble EDTA-linked chitosan as a zwitterionic flocculant for pH sensitive removal of Cu(II) ion

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, H-1 and C-13 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

Selection of Neighboring Group Participation Intermediates of Fully Acylated Donors around the Glycosylation Sites in Oligosaccharide Acceptors

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 beta-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

The DNA-based gels for oral delivery of probiotic bacteria

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.Published in Macromolecular Bioscience, 2006, Wiiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Biosorption of nonylphenol on dead biomass of Rhizopus arrhizus encapsulated in chitosan beads

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 immobilisation 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-Schlüender > 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 x 10^[-4] to 1.8950 x 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

Synthesis of a tetrasaccharide repeating unit of O-antigenic polysaccharide of Salmonella enteritidis by use of unique and odorless dodecyl thioglycosyl donors

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

Pre-activation of fully acetylated dodecyl thioglycosides with BSP-Tf2O led to efficient glycosylation at low temperature

Fully acetylated dodecyl thioglycosides found to be used as glycosyl donors by activation with 1.benzenesulfinyl piperidine (BSP) and triflic anhydride (Tf2O) at -78℃, and the glycosyl acceptor was added to the reaction mixture at the same temperature to furnish various disaccharides and Lewis a (Le^a) trisaccharide in good yields

Cyclodextrin-linked alginate beads as supporting materials for Sphingomonas cloacae, a nonylphenol degrading bacteria

Calcium alginate beads covalently linked with α-cyclodextrin (α-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 α-CD-alginate beads with diameter of 657 ± 82 μm and with degree of CD substitution of 0.16 showed a strong affinity for nonylphenol adsorption. Although addition of α-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 α-CD-alginate-beads showed 46% nonylphenol recovery after 10-day incubation at 25 ± 2℃, 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

Intramolecular Glycosylation Approach toward Constructing the Macrocyclic Structure of Resin Glycosides

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.LETTE