The mannan formed by the yeastBullera tsugae

The structure of an extracellular mannan formed by the yeastBullera tsugae has been studied. It has been shown that the repeating unit of this polysaccharide contains -(13)- and -(14)-bound D-mannopyranose residues in equimolar ratio. A comparison has been made of the polymer under investigation with the extracellular mannan from a yeast of the genusRhodotorula. Leningrad Institute of Pharmaceutical Chemistry. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 746–750, November–December, 1985.     

松杉灵芝不同部位的红外光谱分析研究

采用红外光谱三级鉴定法对松杉灵芝菌盖、表皮、菌柄、子实体不同部位的红外光谱图进行了整体分析。结果表明:松杉灵芝的各部位均含萜类、甾醇类、氨基酸、多肽、蛋白质和糖苷类等物质。在松杉灵芝的一维红外光谱中,菌盖的1 649cm-1峰的相对强度明显比表皮、菌柄和子实体强,说明菌盖中所含的氨基酸、多肽、蛋白质物质的量比其它部位高;在二阶导数谱中,四者在1 720~1 600cm-1范围内峰形差别较大,进一步说明松杉灵芝不同部位所含氨基酸、多肽、蛋白质物质不一致;而二维相关红外光谱中,各部位自动峰的数目、峰位置和峰相对强度都有所不同,可推断松杉灵芝各部位本身所含的糖苷类物质是不一致的。     

Antitumor Active Protein-containing Glycans from the Body of Ganoderma tsugae

To explore the effects of traditional herbal medicine Ganoderma tsugae(G. tsugae) on immunomodulatory and antitumor activities, the crude polysaccharides of G. tsugae were purified by filtration, diethylaminoethyl(DEAE) sepharose-fast flow chromatography and sephadex G-100 size-exclusion chromatography. Two main fractions, protein- containing glycans CSSLP-1 and CSSLP-2, were obtained via the gradient elution. The protein content, molecular weight, and monosaccharide composition of the two fractions were analyzed. Furthermore, the influence of the protein-containing glycans from G. tsugae on the activation of human acute monocytic leukemia cell line(THP-1) and their antitumor activities to the human hepatocellular liver carcinoma cell(HepG-2) in vitro were evaluated. The results indicate that CSSLP-1 and CSSLP-2 could increase the pinocytic activity of THP-1 cells and induce THP-1 cells to produce the cytokines of TNFα and IL-2, significantly. CSSLP-1 and CSSLP-2 also played an inhibiting effect on the cancer cell(HepG-2). Moreover, the anti-proliferation activity of CSSLP-1 and CSSLP-2 increased with the participation of TNFα and IL-2 or other antitumor factors induced from THP-1 cells by G. tsugae protein-containing glycan fractions.     

二茂铁吩开环聚合合成茂金属有机高分子研究进展

综述了近年来二茂铁吩化合物的合成及其开环反应的研究进展,同时总结了聚茂金属有机高分子的性质及其应用。     

Bidentate ligands formed by self-assembly

A novel supramolecular strategy to prepare bidentate ligands via the assembly of functionalised monomeric ligands on a dimeric zinc(II) porphyrin template is presented; the assembled bidentate ligands show chelating behaviour and their rhodium complexes display enhanced selectivity in the hydroformylation compared to the non-template analogue.     

The unimolecular dissociation of protonated phenyl ethers formed by chemical ionization

A series of phenyl ethers with cyclic and acyclic olefins has been observed to form proton-bound complexes on protonation under chemical ionization conditions with methane as the reagent gas. The competitive dissociations of these complexes have been studied by ion kinetic energy spectrometry and the measured branching ratios have been correlated with the relative stabilities of the product species.     

The structure and spectra of H-bonded complexes formed by 2-pyridone

The self-assembly complexes formed by 2-pyridone derivatives were theoretically studied by the AM1 and DFT methods to determine their binding energies. The UV, IR, and NMR spectra of the complexes were calculated using the INDO/CIS, AM1, and B3LYP/3-21G methods, respectively. It was shown that the complexes could be formed by two monomers via double hydrogen bonding thanks to the negative binding energy. The affinity for binding was increased by substituents in the monomers. But this stimulating effect depended on the simultaneous influence of the electronic and steric effects. The first absorption bands in the UV spectra of the complexes were blue-shifted relative to that of the monomer because of their larger LUMO-HOMO energy gaps. As hydrogen bonds were formed, the N-H stretching vibrations of the monomers were weakened in the IR spectra of the complexes. And the chemical shifts of the C=C and C≡C carbon atoms were shifted downfield in the ¹³C NMR spectra. The article is published in the original.     

The properties of BCN films formed by ion beam assisted deposition

A study has been made on the formation and the properties of boron carbonnitride (BCN) thin films. The BCN films were produced by ion beam assisted deposition, in which boron and carbon were deposited by electron beam heating and nitrogen was supplied by ion implantation simultaneously. The mechanical properties of BCN films were measured using a ultra micro hardness tester and a friction tester. The atomic ratio and the structure of BCN thin films were estimated by means of X-ray photoelectron spectroscopy, laser Raman spectroscopy and Fourier transform infrared spectroscopy. As preliminary results, it was found that the BCN films are higher in hardness and lower in friction coefficient than diamond-like carbon (DLC) films. The mechanical properties are discussed with the relation of surface composition and structure.     

Hydrolyzability of mannan after adsorption on cellulose

During the pretreatment of lignocellulosic materials, the dissolved mannan would re-adsorb on cellulose, and then inhibited the cellulose hydrolysis by cellulases. However, the adsorption of mannan on cellulose and hydrolyzability of mannan adsorbed on cellulose were not so clear. In this work, the adsorption behavior of mannans on cellulose and the hydrolysis of adsorbed mannan by mannanase were investigated. Adsorption of 1, 4-β-D-mannan (mannan), Konjac glucomannan (GM), and Carob galactomannan (GalM) on Avicel and corn stover (CS) was increased with mannan loading. The adsorbed amount of mannan (94.4 mg/g Avicel and 85.1 mg/g CS) on cellulosic substrates at the mannan concentration of 5 mg/mL was significantly higher (p < 0.05) than that of GM (65.7 mg/g Avicel and 63.7 mg/g CS) and GalM (44.3 mg/g Avicel and 48.7 mg/g CS). Furthermore, the NMR spectra and molecular weight analysis showed that mannan with less side groups and low molecular weight might increase the adsorption. Mannan, GM, and GalM adsorbed on Avicel and CS, which was used as Avicel/CS -mannan/GM/GalM complex, could be hydrolyzed by mannanase, and the hydrolyzability of Avicel-mannan/GalM complexes was stronger than that of Avicel-GM complex. Similarly, the reducing sugars increased by 23.2 and 54.2 % for Avicel-mannan and Avicel-GalM complexes after 48 h hydrolysis by cellulase and mannanase, respectively. The results suggested that the addition of mannanase could hydrolyze the mannan adsorbed on cellulose and potentially improved hydrolysis efficiency of cellulose in lignocelluloses. Additionally, the mannanase supplementation could be extended to the removal of mannan on pulp by mannanase and finally affecting the dissolving pulps and paper quality.     

Nonlamellar phases formed by membrane lipids

A brief rewiev of membrane lipids forming cubic and reversed hexagonal phases is presented. An emphasis is made on anionic lipids and particular microbial lipids.     

Supramolecular polymers formed by cinnamoyl cyclodextrins

6-Cinnamoyl α-cyclodextrin (6-CiO-α-CD) and 6-cinnamoyl β-cyclodextrin (6-CiO-β-CD) were prepared. 6-CiO-α-CD formed intermolecular complexes to give supramolecular oligomers. 6-CiO-β-CD formed insoluble supramolecular complexes in the solid state. The structures of these complexes are discussed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3519–3523, 2003     

Layered structures formed by dinitrobenzoic acids

3,5-dinitrobenzoic acid, 1 and 3,5-dinitro-4-methylbenzoic acid, 2, form cocrystals with 4,4′-bipyridyl but only the latter forms a layered structure, which can incorporate anthracene molecules. Furthermore, 2 forms a pillared type structure with thionicotinamide.     

Elucidation of the isomeric domains formed by sodium N-dodecanoyl-L-prolinate

Investigations aimed at clarifying the nature of geometrical domains of amidic sodium N-dodecanoyl-l-prolinate are reported. NMR investigations on the association of aromatic solutes with the aggregates formed by the amidic surfactant in water show the selective binding of some solutes to the Z domains. Fluorescence quenching experiments allowed us to measure the aggregation number of the aggregates. SAXS experiments gave the average size and structural features of the aggregates. A NMR ROESY experiment evidenced the mosaic-like nature of the domains inside the same aggregate.