Research progress of nitrobenzoyl sesquiterpenoids as marine characteristic natural products / 药学学报

Sesquiterpenoids are widely found in nature, while nitrobenzoyl sesquiterpenoids are relatively rare. Twelve natural nitrobenzoyl sesquiterpenoids were all derived from marine Aspergillus fungi, which are typical natural products with marine characteristics. These natural products exhibit good antitumor, antiviral, and inhibition of osteoclast differentiation activity, especially in the treatment of osteoclast-related diseases, showing good medicinal development value. This article reviews the natural product sources, chemical structure, chemical synthesis, biosynthesis, bioactivity, and pharmacological mechanisms of nitrobenzoyl sesquiterpenoids and predicts and discusses their absorption, distribution, metabolism, excretion, toxicity (ADME/T), and drug-likeness, providing a comprehensive understanding of the natural products of nitrobenzoyl sesquiterpenoids from marine sources and their potential for pharmaceutical development.

Study on the surface fungus diversity of commercially Platycladi semen based on high-throughput sequencing technology / 药学学报

The structural composition of the surface fungal community of commercially Platycladi semen was analyzed to reveal the surface fungal biodiversity and structural differences. Platycladi semen was collected from Henan, Shandong and Hong Kong, their DNA was extracted, ITS fragments in DNA were amplified by PCR. Miseq was sequenced on Illumina Hiseq 2500 platform after the PCR products were qualified for quality inspection. The sequence OTU cluster was obtained and bioinformatics analysis was carried out. Microbial communities were not observed in the eyes of the Platycladi semen in the three regions. Sequencing results showed that the surface microbial community had high biodiversity, but there were significant differences in species composition. Seven samples o Platycladi semen obtained 345 947 valid sequences, which were divided into 267 OTUs, 3 phylums. 18 classes, 40 orders, 82 families, 120 genus, 191 species fungi. At the genus level, Aspergillus is the dominant species, accounting for the highest proportion, reaching (93.36 ± 6.01)%. Seven samples were contaminated by Aspergillus flavus, and the pollution levels were 14.58%, 15.98%, 17.64%, 16.44%, 0.97%, 23.39% and 18.86%. Except sample No. 5, Aspergillus cibarius was the most abundant, the other six samples were Aspergillus niger, Aspergillus fumigatus and Aspergillus flavus as the core microflora. By analyzing the diversity of fungi distribution in different habitats, we can fully understand the fungi on the surface of Platycladi semen, lay a foundation for early risk warning of Aspergillus flavus contamination and its aflatoxin contamination, and provide a theoretical basis for the quality and safety of Platycladi semen.

Thermotolerant and mesophylic fungi from sugarcane bagasse and their prospection for biomass-degrading enzyme production

Nineteen fungi and seven yeast strains were isolated from sugarcane bagasse piles from an alcohol plant located at Brazilian Cerrado and identified up to species level on the basis of the gene sequencing of 5.8S-ITS and 26S ribosomal DNA regions. Four species were identified: Kluyveromyces marxianus, Aspergillus niger, Aspergillus sydowii and Aspergillus fumigatus, and the isolates were screened for the production of key enzymes in the saccharification of lignocellulosic material. Among them, three strains were selected as good producers of hemicellulolitic enzymes: A. niger (SBCM3), A. sydowii (SBCM7) and A. fumigatus (SBC4). The best β-xylosidase producer was A. niger SBCM3 strain. This crude enzyme presented optimal activity at pH 3.5 and 55 °C (141 U/g). For β-glucosidase and xylanase the best producer was A. fumigatus SBC4 strain, whose enzymes presented maximum activity at 60 °C and pH 3.5 (54 U/g) and 4.0 (573 U/g), respectively. All these crude enzymes presented stability around pH 3.0–8.0 and up to 60 °C, which can be very useful in industrial processes that work at high temperatures and low pHs. These enzymes also exhibited moderate tolerance to ethanol and the sugars glucose and xylose. These similar characteristics among these fungal crude enzymes suggest that they can be used synergistically in cocktails in future studies of biomass conversion with potential application in several biotechnological sectors.

Bioleaching of gold, copper and nickel from waste cellular phone PCBs and computer goldfinger motherboards by two Aspergillus nigerstrains

In an effort to develop alternate techniques to recover metals from waste electrical and electronic equipment (WEEE), this research evaluated the bioleaching efficiency of gold (Au), copper (Cu) and nickel (Ni) by two strains of Aspergillus niger in the presence of gold-plated finger integrated circuits found in computer motherboards (GFICMs) and cellular phone printed circuit boards (PCBs). These three metals were analyzed for their commercial value and their diverse applications in the industry. Au-bioleaching ranged from 42 to 1% for Aspergillus niger strain MXPE6; with the combination of Aspergillus niger MXPE6 + Aspergillus niger MX7, the Au-bioleaching was 87 and 28% for PCBs and GFICMs, respectively. In contrast, the bioleaching of Cu by Aspergillus niger MXPE6 was 24 and 5%; using the combination of both strains, the values were 0.2 and 29% for PCBs and GFICMs, respectively. Fungal Ni-leaching was only found for PCBs, but with no significant differences among treatments. Improvement of the metal recovery efficiency by means of fungal metabolism is also discussed.