Linyong Zheng

Characterisation and immunostimulatory activity of an α-(1→6)-d-glucan from the cultured Armillariella tabescens mycelia

IPS-B2, an intracellular polysaccharide with anti-tumor effect, was isolated from cultured Armillariella tabescens mycelia by hot water extraction, anion-exchange and gel chromatography. Based on the results of paper chromatography (PC), gas chromatography (GC), infra-red (IR) spectroscopy and (13)C NMR, IPS-B2 was characterized as an α-(1→6)-d-glucan with a molecular weight of 49.5kDa. The effects of IPS-B2 on murine peritoneal macrophages were further investigated. The results demonstrated that IPS-B2 induced nitric oxide (NO) and cytokines (TNF-α, IL-1β and IL-6) production in macrophages. The outcomes of real-time reverse transcription-polymerase chain reaction (RT-PCR) proved that the transcribing level of inducible NO synthase (iNOS), TNF-α, IL-1β and IL-6 mRNA in the peritoneal macrophages have been augmented by IPS-B2. These data suggest that the anti-tumor activity of the polysaccharide from A. tabescens may due to activation of macrophage.

Molecular Diversity of Auricularia polytricha Revealed by Inter-Simple Sequence Repeat and Sequence-Related Amplified Polymorphism Markers

Due to unsatisfying attempts to fingerprint Auricularia polytricha, two different molecular maker systems—Inter-Simple Sequence Repeats (ISSR) and Sequence-related amplified polymorphism (SRAP)—were established and tested to quantify molecular diversity among 19 strains of this fungus. A total of 202 (99.0%) and 459 (95.9%) polymorphic bands were detected by 13 ISSR primers and 14 SRAP primer combinations, respectively. By parsimony method, a phylogenetic tree was constructed based on each analysis; the two trees show that 19 A. polytricha strains were distributed into five or four groups. These results demonstrated that both methods were suitable for discriminating among strains of A. polytricha, and the novel SRAP markers are more efficient and preferable. The result also indicated the high level of genetic diversity of A. polytricha and their relationship between each other. These findings would benefit future research in A. polytricha, especially in breeding and medicine development. It also gives a useful method for fingerprinting of other fungi.

Chemical compositions and volatile compounds of Tricholoma matsutake from different geographical areas at different stages of maturity

Tricholoma matsutake is a commercially important edible fungus. Volatile compounds, chemical compositions, and nutritional values of fruiting bodies at different stages of maturity from different geographical areas were analyzed. The main volatile compounds in T. matsutake fruiting bodies were (E)-2-octenal, phenylacetaldehyde, 3-octanone, methyl cinnamate, benzaldehyde, and 1- octen-3-ol. Kinds and levels of volatile compounds from different geographical areas varied. As the fruiting bodies aged, levels of methyl cinnamate and 1-octen-3-ol gradually declined. Potassium was the most abundant element in T. matsutake fruiting bodies. Of 17 amino acids detected in fruiting bodies, glutamate was the most abundant. Volatile compounds, chemical compositions, and nutritional values of T. matsutake varied with age and geographical origin and can serve as chemical indicators for classication of T. matsutake from different geographical areas and at different stages of maturity.

Mineral constituents of a prized edible mushroom ( Tricholoma matsutake ) and soils beneath the fruiting bodies from the production areas across China

Fruiting bodies (500 g per site) of Tricholoma matsutake and the surface layer of soils collected from 20 spatially distant areas with pristine backgrounds across China were analyzed for potassium, magnesium, calcium, zinc, iron, copper, manganese and cadmium using inductively coupled plasma optical emission spectroscopy. In terms of the bioconcentration and bioexclusion concept, K, Mg, Zn, and Cu were highly bioconcentrated, and their bioconcentration factor values varied between 75-615, 2-107, 38-603 and 7-76, respectively, across the 20 sites. Fe, Mn and Cd were moderately bioconcentrated and their bioconcentration factors (BCFs) varied between 0.6-34.0, 0.4-37.0 and 0.9-7.0 respectively. However, Ca was excluded (BCF<1). T. matsutake is a species that is harvested in the wild as a valuable food and can contain a wide spectrum of both essential and hazardous mineral compounds that accumulate at elevated concentrations even if grown in pristine areas. The estimated intake rate of Cd in the fruiting bodies indicates cause for concern associated with this metal resulting from the daily consumption of between 200 and 400 g of fruiting bodies on a frequent basis during the mushrooming season.

Isolation of a wild Morchella spp. strain and the effects of its extract on ethanol-induced gastric mucosal lesions in rats.

A Morchella spp. strain was isolated from a wild morel mushroom, and the effects of its mycelia extract on the ethanol-induced gastric mucosal lesions of rats were investigated in vivo. Sequence analysis of internal transcribed spacer suggested that this Morchella spp. strain (strain No. M1) was clustered together with M. conica in the phylogenetic tree. The superoxide dismutase (SOD) activity increased significantly compared to the control. However, the malondialdehyde (MDA) level and myeloperoxidase (MPO) activity decreased significantly compared to the control. These results indicated that M1 is one member of M. conica and the protective effects of M1 extract against the ethanol-induced gastric lesions may be related to the increased SOD activity and decreased MDA level and MPO activity in rats.