[Effects of nitrogen level on growth of Tetrastigma hemsleyanum and phytochemical content and antioxidant activity in stems and leaves].

As a rare endangered medical plant that newly cultivated,little experimental information is available for growth and metabolites of Tetrastigma hemsleyanum in response to nitrogen( N). The effects of different levels of N on growth of T. hemsleyanum and the content of phytochemicals( polysaccharide,total flavonoids and phenolics) and antioxidant activity( ABTS and FRAP) in stems and leaves were investigated in this study. A certain amount of N had positive effects on most of biological traits,and excessive dose of N went against growth of T. hemsleyanum. With N levels decreased,the polysaccharide content in stems and leaves had no significant change,while the total flavonoid and phenolic content,and antioxidant activities increased steadily. Antioxidant activities and total flavonoid and phenolic content had significant positive correlation. Excessive N fertilizer should be avoided by cultivation.

Silver nanoparticles in situ synthesized by polysaccharides from Sanghuangporus sanghuang and composites with chitosan to prepare scaffolds for the regeneration of infected full-thickness skin defects.

In recent years, silver nanoparticles have widely been used in antibacterial dressings to solve antibiotic resistance problems. However, traditional methods for reducing silver nanoparticles are usually toxic. To overcome this problem, Sanghuangporus sanghuang polysaccharides (FSHPs) were used as a green reducing agent to prepare silver nanoparticles (AgNPs) with a size of 3-35 nm. The FSHPs­silver nanoparticles (FSHPs-Ag) composite with chitosan solution were then freeze-dried to obtain a porous sponge dressing of chitosan-FSHPs-Ag (CS-FSHPs-Ag). The internal pores of CS-FSHPs-Ag were between 50 and 100 µm and had good swelling and water retention properties, which could provide a moist environment for wounds. Based on the experimental results, the appropriate concentration of AgNPs required for CS-FSHPs-Ag to inhibit Escherichia coli and Staphylococcus aureus was determined. Moreover, there was no statistically significant difference between the material treatment and the blank control group, indicating that the material almost showed no toxicity to L929 cells. Finally, this material was used for dressing animal wounds. The results showed that the CS-FSHPs-Ag promoted wound contraction and internal tissue growth better than the wounds treated with Aquacel® Ag, which indicated that the CS-FSHPs-Ag has a great potential as an ideal wound dressing material.

Structure characterization and biological activities of a pectic polysaccharide from cupule of Castanea henryi.

A pectic polysaccharide (CHIP3) was fractionated from the natural cupule of Castanea henryi. It contained mannose (10.70%), rhamnose (8.70%), galacturonic acid (38.21%), galactose (13.75%) and arabinose (28.63%) with a molecular weight of 2.44 × 104 g/mol by multi-laser light scattering. The structure was elucidated by using FT-IR spectroscopy, methylation analysis and NMR analysis. Results showed that the backbone of CHIP3 consisted of 1, 4-α-linked d-GalpA residues containing the non-methyl-esterified carboxyl groups, interspersed with a few 1,2-α-l-Rhap units. Its side chains were attached by two branches to O-4 of Rhap with 1,4-ß-linked d-Galp units and 1,5-α-l-linked Araf units bearing 3,5-substituted α-l-linked Araf residues as branching points. AFM data revealed it existed as a flexible chain in 0.1 M NaNO3 aqueous solution. Furthermore, CHIP3 was demonstrated to have notable antioxidant activity of FRAP, ABTS+ radical scavenging and reducing power. Cytotoxicity assay showed it displayed inhibitory activity against HepG2 cells with IC50 values of 242.6 µg/mL.

Association of various fruiting body macromorphological traits with spore yield in Ganoderma Lingzhi (higher Basidiomycetes), a new medicinal mushroom from China.

To study the correlations and relationship between spore yield and various macromorphological traits of Ganoderma lingzhi, a field experiment was conducted in a randomized block design with 3 replications. Ten macromorphological traits, including pileus diameter, pileus crust thickness, context thickness, tube thickness, pileus thickness, stipe length, stipe diameter, stipe weight, pileus weight, and spore yield, were recorded for all of the tested strains. There was significant variation among the strains for all of the traits studied. The results indicated that the highest variation was observed in spore yield and pileus weight. Correlation studies revealed that among 9 macromorphological traits, only the pileus weight of the fruiting body was significantly positively correlated with spore yield (r2 = 0.674*). Pileus diameter showed significant positive association with pileus weight of fruiting body (r2 = 0.838*). Stepwise multiple regression analysis showed that pileus weight and spore yield had a linear relationship (spore yield = -21.95 + 1.51 * pileus weight). The coefficient of determination of stepwise regression analysis (r2 = 0.4543) revealed 45.43% variation in the spore yield because of its relationship with pileus weight. Regression coefficient (b = 1.51) showed that a unit (1 g) increase in the pileus weight of the fruiting body resulted in a proportional increase of 1.51 g in spore yield. The derived information would be very useful when selecting potentially breeding strains for future G. lingzhi improvement programs.

Structural features of a new heteropolysaccharide from the fruit bodies of Melia azedarach and its effect on cytotoxic activity.

Water-soluble polysaccharides were extracted from the fruit pulps of Melia azedarach and some columns were undertaken to isolate the major polysaccharide (MPS-III). Its structural features were elucidated by IR analysis, carbohydrate analysis, periodate oxidation, Smith degradation, methylation analysis and NMR spectroscopy. Then it was evaluated for the cytotoxic activity in vitro against four human cell lines, using the sulphorhodamine B assay. The data obtained indicated that MPS-III contains a alpha(1-->4) main chain backbone composed of arabinose, mannose in a molar ratio of 1.31:1.0 and has alpha(1-->6) branch structure. And MPS-III showed a strong cytotoxic activity in the BGC-823 cell line.