Xuanwei Zhou

Cordyceps fungi: natural products, pharmacological functions and developmental products

Objectives Parasitic Cordyceps fungi, such as Cordyceps sinensis, is a parasitic complex of fungus and caterpillar, which has been used for medicinal purposes for centuries particularly in China, Japan and other Asian countries. This article gives a general idea of the latest developments in C. sinensis research, with regard to the active chemical components, the pharmacological effects and the research and development of products in recent years.

A review: recent advances and future prospects of taxol-producing endophytic fungi

In the urgent search for more effective ways to treat cancer, new extraction methods of taxol from endophytic fungus have demonstrated high potential in increasing the efficiency of taxol extraction for more efficient and sustainable production of taxol and cancer treatment products. This paper summarizes recent advances in taxol-producing endophytic fungi, both in China and abroad, in the following areas: isolation and identification of endophytic fungi types, extraction and detection methods of endophytic taxol in plants, and improved efficiency of the extraction process. With the advancement of science and technology, new techniques in biotechnology, such as fungal strain improvement and recombining technique and microbial fermentation engineering, have increased the extraction yield from taxol-producing fungi, thereby improved the overall efficiency of taxol production.

Ganodermataceae: Natural Products and Their Related Pharmacological Functions

The objective of this paper is to review the natural products and the pharmacological functions of Ganodermataceae family. Presently, studies on the bioactive components of Lingzhi are focused on polysaccharides and triterpenes/triterpenoids compounds. New Ganoderma polysaccharides, including their molecular weights, glycosyl residue compositions, glycosyl linkage and branches, are summarized in this paper. Also presented are new types of triterpenes and their characteristics from Lingzhi. Taking Ganoderma lucidum as an example, we reviewed its pharmacological functions in anti-tumor and immune-modulating activities for treating hypoglycemosis, hepatoprotection, and the effect on blood vessel system. Based on the advances in Lingzhi research in the past few decades, both G. lucidum and G. sinense are considered as the representative species of medicinal mushroom Lingzhi in China. Until 2001, G. tsugae was only advised to be used as the materials of the health products. The biologically-active components related to pharmacological functions of these three species were studied more than other Ganodermataceae family species; however, which have been used in less modern folk medicine.

Screening of taxol-producing endophytic fungi from Taxus chinensis var. mairei

A total of 38 endophytic fungus strains were isolated from Taxus chinensis var. mairei by the aseptic technique. Genomic DNA was extracted from isolated endophytic fungi and subjected to polymerase chain reaction (PCR) analysis for the presence of the Taxus taxadiene synthase (TS) gene, a rate-limiting enzyme gene in the taxol biosynthetic pathway. Twelve out of 38 isolated endophytic fungus strains showed PCR positive for the ts gene. Subsequently, taxol and its related compounds were extracted from culture filtrates and mycelia of the PCR positive strains, separated by column chromatography, and analyzed by High Performance Liquid Chromatography and Mass Spectrum. The analysis result showed that 3 strains could produce taxol and its related compounds at the detectible level. This study indicates that molecular detection of the ts gene is an efficient method for primary screening of taxol or its related compound-producing endophytic fungi, which can improve prominently screening efficiency.

Recent status and prospects of the fungal immunomodulatory protein family

With the exception of polysaccharides and triterpenes/triterpenoids compounds, fungal immunomodulatory protein (FIP), a small molecule protein, is also an important bioactive component with immune regulating activity. It plays a significant role in immunomodulating. The objective of this paper was to review the latest advances in various aspects of research on FIPs, including their basic components and structural character, characters of diversity, gene cloning and expression, and their biological function, etc. In addition, prospects of utilization value and the exploitation foreground of FIPs were also discussed. The review will provide a useful reference for further research, development, and utilizations of FIPs.

Advances in research of the artificial cultivation of Ophiocordyceps sinensis in China

Abstract Ophiocordyceps sinensis (syn. Cordyceps sinensis), a traditional Chinese medicine called DongChongXiaCao (DCXC) in Chinese, is well known and has been used in Asia countries since the fifteenth century, and it contains some valuable medicinal component defined by modern pharmacological science. DCXC only appears at high altitudes on the Qinghai-Tibetan Plateau. Consequently, it is difficult to find and harvest. Because of its rarity and medicinal value, DCXC has always been one of the most expensive medicines known. As the price of DCXC has risen in recent years, thousands of migrants have entered into the various grasslands to search for them in season, which makes ecological environments of the grassland more fragile. In order to relieve the environmental pressures and protect this valuable resource, the artificial cultivation of DCXC involving two aspects of the genus Hepialus and the fungi of the host larvae should be employed and applied at the first available time point. In this article, the reproduction of moth larvae of the genus Hepialus is first described, which includes their ecological characteristics and the methods of artificial feeding. Second, the generation and isolation method of the fungi from DCXC are subsequently summarized, and then the mechanism of fungal spores to attack the moth larvae are restated. Finally, the basic model of artificial cultivation of DCXC is introduced; meanwhile, the potential application of modern biotechnology to the artificial cultivation is analyzed in prospect. This review article will not only expand people’s knowledge regarding the artificial cultivation of DCXC, but also hopefully provide an informative reference for the development of this valuable resource and the environmental protection of alpine meadows.

Protoplast formation, regeneration and transformation from the taxol-producing fungus Ozonium sp .

The effects of some factors on protoplast isolation and regeneration from taxol-producing fungus Ozonium sp. BT2 were investigated, including the enzymolysis time and temperature, the osmotic pressure stabilizer, mycelial incubation time, the culture medium, the culture methods and preprocessing. The mycelia were digested by enzyme combination of 1.5% lywallzyme, 0.5% snailase, 1.5% cellulase and 1.0% lysozyme for 3 h at 30°C, and a high yield of protoplasts (1.31 ◊ 10 8 /g moist mycelia) were obtained. The protoplasts were purified, and then regenerated by different culture methods. The results showed that regeneration frequency was not different. The protoplasts could regenerate on both PDA and Czapek medium with 0.6 M sucrose, 0.6 M sodium chloride and 0.6 M mannitol, respectively. The regeneration rate was about 2.56% under 25°C on Czapek medium using 0.6 M sodium chloride as osmotic pressure stabilizer. Furthermore, transformants were obtained by transforming the protoplasts with plasmid pAN7-1 carrying hygromycin B phosphotransferase gene (hph) conferring hygromycin resistance. This study provides the foundation to develop an engineered strain of taxol-producing fungus by protoplast mutagenesis, fusion and genetic transformation.

Cloning and Characterization of a Curcin Gene Encoding a Ribosome Inactivating Protein from Jatropha curcas

A curcin gene was isolated by using genomic walker technology and revealed to encode the type-1 ribosome inactivating proteins (RIPs). Analysis of 1802 bp segments revealed the gene including a 694 bp 5′ flanking region, a 882 bp open read frame (ORF) and a 226 bp 3′ flanking region. There are one putative TATA boxes and two possible CAAT box lie in the 5′-flanking region. The ORF encodes a 32 kDa precursor, which contains a 42 amino acid signal peptide. Two possible polyadenylation signals are found in the 3′-flanking region. No introns were found, which is typical of other RIPs gene that has been sequenced. The deduced amino acid sequence of Curcin gene coding region shares high homology with RIPs, e.g. ricin A-chain, gelonin, abrin A-chain, bryodin, trichosanthin and momorcharin, which were found to be 34% (99/287), 34% (98/287), 37% (89/240), 34% (86/249), 36% (87/241) and 36% (88/241), respectively. The cloning of the gene is important foundation to further study the structure, expression and regulation mechanism.

Applied modern biotechnology for cultivation of Ganoderma and development of their products.

A white-rot basidiomycete Ganoderma spp. has long been used as a medicinal mushroom in Asia, and it has an array of pharmacological properties for immunomodulatory activity. There have been many reports about the bioactive components and their pharmacological properties. In order to analyze the current status of Ganoderma products, the detailed process of cultivation of Ganoderma spp. and development of their products are restated in this review article. These include the breeding, cultivating, extracting bioactive component, and processing Ganoderma products, etc. This article will expand people’s common knowledge on Ganoderma, and provide a beneficial reference for research and industrial production.

Cytokines Expression Induced by Ganoderma sinensis Fungal Immunomodulatory Proteins (FIP-gsi) in Mouse Spleen Cells

Ganoderma sinensis fungal immunomodulatory protein (FIP-gsi) was a new member of FIPs family. Based on the cloning of FIP-gsi gene from G. sinensis, this paper reported that FIP-gsi gene was expressed in Escherichia coli expression system. Then, the recombinant proteins were analyzed by the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Finally, the immunomodulatory activity was examined by inducing cytokine genes expression. The results showed that the recombinant FIP-gsi protein could be expressed in E. coli and got the yield of about 25% of the soluble form in the total soluble protein. The FIP-gsi protein was composed of 111 amino acids, and the sequence of homologous rate was 88.6% with FIP-glu (LZ-8). Furthermore, it could enhance the levels of interleukin (IL)-2, IL-3, IL-4, interferon gamma, tumor necrosis factor alpha, and IL-2 receptor (IL-2R) in mouse spleen cells.