[Study of mycelial polysaccharide from Paraisaria dubia of Ophiocordyceps gracilis asexual].

In order to provide a foundation for the development and application of Ophiocordyceps gracilis and increase the new resources of cordyceps,an asexual Paraisaria dubia was isolated from an O. gracilis fruit body. After 10 days of liquid fermentation,white globular mycelium and clear transparent fermentation were produced. The mycelium was extracted by hot water and precipitated with ethanol to obtain intracellular crude polysaccharide. The protein was deproteinized to obtain deproteinized polysaccharide. The intracellular pure polysaccharide was purified by Sepharose 4 B column chromatography and were analyzed by UV,IR,1 H-NMR,and13 CNMR data,as well as GC and HPLC. The results showed that the intracellular polysaccharide of P. dubia was composed of glucose,galactose and mannose with a molar ratio of 25. 54 ∶2 ∶1. It was a ß-configuration glycosylic bond,containing pyranoside. The initial connection of polysaccharide was ß(1→2)(1→4)(1→6) connection. This experiment provides a theoretical basis for the development and application of P. dubia.

(1E,4E)-1-(2-Nitro-phen-yl)-5-(2,6,6-trimethyl-cyclo-hex-1-en-1-yl)penta-1,4-dien-3-one.

In the title curcumin-ionone derivative, C(20)H(23)NO(3), the dihedral angle between the cyclo-hexene and benzene rings is 21.03 (8)°, with both double bonds in the inter-linking olefinic chain adopting E conformations. Two of the methyl-ene groups of the ß-ionone ring are disordered over two sets of sites with occupancy ratios of 0.50:0.50 and 0.60:0.40. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds into zigzag chains extending along the b axis.

[Influence of culture mode on bacterial cellulose production and its structure and property].

Acetobacter xylinum NUST4.2 has been applied in the studies to examine the production, structure and thermal property of bacterial cellulose (BC) produced in stationary culture and in the stirred tank reactor. These differences are as follows: BC yield reached 7.5 g/L in stationary culture for 6 days and its productivity was 0.052 g/L/h. BC production reached 3.13 g/L in the stirred tank reactor for 72h and its productivity was 0.043 g/L/h. SEM showed that there was almost no difference between network structure built of entangled cellulose ribbons produced in static culture and in the reactor. But the cellulose ribbons produced in static culture were a much more entangled and denser network with curved and overlapping cellulose ribbons in comparison with that one produced in the stirred tank reactor. Also the thickness of the cellulose ribbons seems to differ between the two BC samples, with the one from static culture distinguished by the slightly thinner ribbons. FT-IR revealed that there was no effect of stirring on the chemical structure of BC, but intermolecular hydrogen bond of cellulose was weakened. Furthermore, BC synthesized in static culture displayed I(alpha)-rich cellulose. XRD results indicated that no remarkable change in the cellulose crystallographic form of the BC samples. Nevertheless, BC produced in static culture was characterized by a higher crystallinity, higher I(alpha) content and higher crystalline size than cellulose that was produced in the reactor. All of these results revealed that stirring in the reactor interfere strongly in the process of nascent microfibrils crystallization, favoring the formation of smaller size microfibrils and increased I(beta), the more stable allomorph. Compared with cotton cellulose, the changes of thermal decomposition behavior in the BC samples were that BC produced in static culture displayed better thermal stability, but BC produced in the stirred reactor displayed better flame retarding.

[Comparation of Toxic Effect of Silicious Mineral Dusts on Lung Epithelial A549 Cells].

Considering the high contents of minerals and the potential health risk of mineral dusts to human and the environment, this paper was aimed to figure out the toxic effect and mechanism of four common mineral particles (quartz, albite, sericite, and montmorillonite). Cytotoxicity assays for cell viability (MTT assay), membrane integrity (LDH assay), oxidative stress (H2O2 assay) and inflammatory cytokines (TNF-α and IL-6 assay) were applied. The results showed the influence of these mineral particles on A549 cell viability followed the order of momtmorillonite > cericite≥quartz > albite. There was no obvious relation between cell viability and the content of SiO2, however, good linear correlation with the content of iron, and the cytotoxicity of mineral dusts was strengthened with increasing iron content. Mineral dusts generated H2O2 in cell or cell-free systems. In particular, H2O2 exhibited a linear correlation with the iron content, which meant that iron in the mineral dusts played an important role in the generation of reactive radical. Among those samples, oxidative stress induced by montmorillonite was distinctly stronger, while there was negligible influence induced by quartz and albite. Besides, all the tested samples induced damage to A549 cell membrane, and triggered the release of TNF-α or IL-6, but differed by the kinds of mineral dusts. In conclusion, composition and structure directly affected, but were not the only factors that contributed to the biological activity of mineral dusts, the evaluation of cell viability, membrane damage, free radicals and inflammatory reaction induced by mineral dusts should take the external morphology, surface active groups, solubility, adsorption and ion exchange properties into consideration.