An Integrated Strategy Based on 10-DAB Extraction and In Situ Whole-Cell Biotransformation of Renewable Taxus Needles to Produce Baccatin III.

Baccatin III is a crucial precursor in the biosynthesis pathway of paclitaxel. Its main sources are extraction from Taxus or chemical synthesis using 10-deacetylbaccatin III (10-DAB) as substrate. However, these preparation approaches exhibit serious limitations, including the low content of baccatin III in Taxus and the complicated steps of chemical synthesis. Heterologous expression of 10-deacetylbaccatin III-10-O-acetyltransferase (TcDBAT) in microbial strains for biotransformation of 10-DAB is a promising alternative strategy for baccatin III production. Here, the promotion effects of glycerol supply and slightly acidic conditions with a low-temperature on the catalysis of recombinant TcDBAT strain were clarified using 10-DAB as substrate. Taxus needles is renewable and the content of 10-DAB is relatively high, it can be used as an effective source of the catalytic substrate 10-DAB. Baccatin III was synthesized by integrating the extraction of 10-DAB from renewable Taxus needles and in situ whole-cell catalysis in this study. 40 g/L needles were converted into 20.66 mg/L baccatin III by optimizing and establishing a whole-cell catalytic bioprocess. The method used in this study can shorten the production process of Taxus extraction for baccatin III synthesis and provide a reliable strategy for the efficient production of baccatin III by recombinant strains and the improvement of resource utilization rate of Taxus needles.

Comparative study of reactive oxygen species and tetracycline degradation pathways in catalytic peroxodisulfate activation by asymmetric mesoporous TiO2 and the corresponding controlled-release materials.

The removal of trace amounts of antibiotics from water environments while simultaneously avoiding potential environmental hazards during the treatment is still a challenge. In this work, green, harmless, and novel asymmetric mesoporous TiO2 (A-mTiO2) was combined with peroxodisulfate (PDS) as active components in a controlled-release material (CRM) system for the degradation of tetracycline (TC) in the dark. The formation of reactive oxygen species (ROS) and the degradation pathways of TC during catalytic PDS activation by A-mTiO2 powder catalysts and the CRMs were thoroughly studied. Due to its asymmetric mesoporous structure, there were abundant Ti3+/Ti4+ couples and oxygen vacancies in A-mTiO2, resulting in excellent activity in the activation of PDS for TC degradation, with a mineralization rate of 78.6%. In CRMs, ROS could first form during PDS activation by A-mTiO2 and subsequently dissolve from the CRMs to degrade TC in groundwater. Due to the excellent performance and good stability of A-mTiO2, the resulting constructed CRMs could effectively degrade TC in simulated groundwater over a long period (more than 20 days). From electron paramagnetic resonance analysis and TC degradation experiments, it was interesting to find that the ROS formed during PDS activation by A-mTiO2 powder catalysts and CRMs were different, but the degradation pathways for TC were indeed similar in the two systems. In PDS activation by A-mTiO2, besides the free hydroxyl radical (·OH), singlet oxygen (1O2) worked as a major ROS participating in TC degradation. For CRMs, the immobilization of A-mTiO2 inside CRMs made it difficult to capture superoxide radicals (·O2-), and continuously generate 1O2. In addition, the formation of sulfate radicals (·SO4-), and ·OH during the release process of CRMs was consistent with PDS activation by the A-mTiO2 powder catalyst. The eco-friendly CRMs had a promising potential for practical application in the remediation of organic pollutants from groundwater.

Comparative study of the performance of controlled release materials containing mesoporous MnOx in catalytic persulfate activation for the remediation of tetracycline contaminated groundwater.

Controlled release materials (CRMs) are an emerging oxidant delivery technique for in-situ chemical oxidation (ISCO) that solve the problems of contaminant rebound, backflow and wake during groundwater remediation. CRMs were fabricated using ordered mesoporous manganese oxide (O-MnOx) and sodium persulfate (Na2S2O8) as active components, for the removal of antibiotic pollutants from groundwater. In both static and dynamic groundwater environments, persulfate can first be activated by O-MnOx within CRMs to form sulfate radicals and hydroxyl radicals, with these radicals subsequently dissolving out from the CRMs and degrading tetracycline (TC). Due to their excellent persulfate activation performance and good stability, the constructed CRMs could effectively degrade TC in both static and dynamic simulated groundwater systems over a long period (>21 days). The TC removal rate reached >80 %. Changing the added content of O-MnOx and persulfate could effectively regulate the performance of the CRMs during TC degradation in groundwater. The process and products of TC degradation in the dynamic groundwater system were the same as in the static groundwater system. Due to the strong oxidizing properties of sulfate radicals and hydroxyl radicals, TC molecules were completely mineralized within the groundwater systems, resulting in only trace levels of degradation products being detectable, with low- or non-toxicity. Therefore, the CRMs constructed in this study exhibited good potential for practical application in the remediation of organic pollutants from both static and dynamic groundwater environments.

Inotodiol inhibits cells migration and invasion and induces apoptosis via p53-dependent pathway in HeLa cells.

BACKGROUND: Inonotus obliquus, namely as Chaga mushroom, is a medicinal and edible fungus, which is widely used in food and medical fields. Inotodiol, a natural lanostane-type triterpenoid with remarkable pharmacological activities, was isolated from Inonotus obliquus, which its potential anti-tumor molecular mechanism was elaborated poorly. PURPOSE: The aim of the present study was to investigate the effect of Inotodiol on HeLa cell migration, invasion and apoptosis through p53-dependent pathway. STUDY DESIGN AND METHODS: The potential mechanisms of Inotodiol on HeLa cell anti-metastatic and pro-apoptosis via wound healing assay, trans-well invasion assay, flow cytometry, caspase-3 activity assay and western blot analysis were studied, as well as the involvement of p53 signaling pathway in anti-metastatic and pro-apoptosis of Inotodiol. Besides, the function of tumor suppressor p53 was further verified by small interfering RNA. RESULTS: Firstly, the cell viability assay showed that low-concentration of Inotodiol had no cytotoxicity to HeLa cells and whereas the concentration above 25 µM significantly inhibited HeLa cell growth and even induced apoptosis. This result was further demonstrated by cell proliferation and morphology assay. Secondly, in vitro wound healing and trans-well invasion assays reported that low-concentration treatment of Inotodiol significantly inhibited cells migration and invasion in a dose-dependent manner, the western blot analysis of matrix mettalloprotinase-2 (MMP2) and matrix mettalloprotinase-9 (MMP9) levels were also decreased. Moreover, Inotodiol notably induced tumor cell apoptosis by Annexin-V-FITC apoptosis assay, which is associated with activation pro-apoptotic proteins of PARP, cleaved caspase-3 and Bax expression, inhibition anti-apoptotic protein Bcl-2 expression. Finally, the anti-tumor activity of Inotodiol was attenuated by silencing p53 tumor suppressor, the result revealed that pre-treatment with p53-specific small interfering RNA (si-p53) markedly inhibited Intodiol-indeuced HeLa cell apoptosis and decreased the caspase-3 activity. What is more, the inhibitory effect of Inotodiol on tumor migration and invasion was blocked under p53 knockdown. CONCLUSION: To sum up, the present study indicated that Inotodiol possessed the potential to prevent malignant tumor migration and invasion, and it might be a natural active compound candidate for clinical treatment of human cervical cancer.

Application of integrative cloud point extraction and concentration for the analysis of polyphenols and alkaloids in mulberry leaves.

A simple and efficient method based on cloud point extraction and concentration combined with high performance liquid chromatography was developed for the simultaneous separation and determination of five target compounds (deoxynojirimycin, chlorogenic acid, rutin, isoquercitrin and astragalin) in mulberry leaves samples. Firstly, to obtain a high extraction rate, the ultrasound assisted extraction was developed on acid modified Triton X-114 system. Under the optimal conditions, the total maximum extraction yields of five target compounds reached 20.80 mg/g, which was superior to conventional solvent extraction. After the cloud point extraction and concentration, the HPLC analysis parameters of calibration curve, intra-day and inter-day precision, limits of detection for the five target compounds were determined systematically. The proposed method was successfully used to extract, concentrate, separate and determine the polyphenols and alkaloids in mulberry leaves.

[Effect of Long-term Fertilizer Application on the Stability of Organic Carbon in Particle Size Fractions of a Paddy Soil in Zhejiang Province, China].

Effects of chemical fertilizers and organic manure on the soil organic carbon (SOC) content in particle size fractions of paddy soil were investigated in a 17-year long-term fertilization field experiment in Zhejiang Province, China. The inherent chemical composition of silt- and clay-associated SOC was evaluated with solid-state 13C-NMR spectroscopy. Compared to CK (no fertilizer treatment), NPKRS (NPK fertilizers plus rice straw) , NPKOM (NPK fertilizers plus organic manure) , NPK (NPK fertilizers) and OM (organic manure alone) treatments significantly (P <0. 05) increased the SOC content of sand- (2-0.02 mm), silt- (0.02-0.002 mm) and clay-sized (< 0.002 mm) fractions. However, no significant difference was observed in the accumulation of silt- and clay-associated SOC between CK and rice straw (RS) treatments. Besides, in comparison with plots applied with NPK fertilizers alone, combined application of organic amendments and NPK fertilizers facilitated the storage of newly sequestered SOC in silt- and clay-sized fractions, which could be more conducive to the stability of SOC. Based on 13C-NMR spectra, both silt and clay fractions were composed of Alkyl-C, O-alkyl-C, Aromatic-C and carbonyl-C. Changes in the relative proportion of different C species were observed between silt and clay fractions: the clay fraction had relatively more Alkyl-C, carbonyl-C and less O-alkyl-C, Aromatic-C than those in the silt fraction. This might be ascribed to the fact that the organic matter complexed with clay was dominated by microbial products, whereas the silt appeared to be rich in aromatic residues derived from plants. The spectra also showed that the relative proportion of different C species was modified by fertilization practices. In comparison with organic amendments alone, the relative proportion of Alkyl-C was decreased by 9.1%-11.9% and 13.7%-19.9% under combined application of organic amendments and chemical fertilizers, for silt and clay, respectively, and that of O-alkyl-C was increased by 2.9%-6.3% and 13.4%-22.1%, respectively. These results indicated that NPKOM and NPKRS treatments reduced the decomposition rate of SOC. The aromaticity, hydrophobicity and, hence, chemical recalcitrance of silt- and clay-associated SOC in the NPK fertilizer treatments were lower than those of the organically amended plots and unfertilized treatments, indicating decreased recalcitrance of SOC against decomposition. We concluded that long-term application of organic manure combined with chemical fertilizers, either through increased accumulation of both recalcitrant compounds and carbohydrates or reduced decomposition of organic matter, was a sustainable strategy for facilitating carbon accumulation of the paddy soil investigated in this study.

Lead accumulation and tolerance of Moso bamboo (Phyllostachys pubescens) seedlings: applications of phytoremediation.

A hydroponics experiment was aimed at identifying the lead (Pb) tolerance and phytoremediation potential of Moso bamboo (Phyllostachys pubescens) seedlings grown under different Pb treatments. Experimental results indicated that at the highest Pb concentration (400 µmol/L), the growth of bamboo seedlings was inhibited and Pb concentrations in leaves, stems, and roots reached the maximum of 148.8, 482.2, and 4282.8 mg/kg, respectively. Scanning electron microscopy revealed that the excessive Pb caused decreased stomatal opening, formation of abundant inclusions in roots, and just a few inclusions in stems. The ultrastructural analysis using transmission electron microscopy revealed that the addition of excessive Pb caused abnormally shaped chloroplasts, disappearance of endoplasmic reticulum, shrinkage of nucleus and nucleolus, and loss of thylakoid membranes. Although ultrastructural analysis revealed some internal damage, even the plants exposed to 400 µmol/L Pb survived and no visual Pb toxicity symptoms such as necrosis and chlorosis were observed in these plants. Even at the highest Pb treatment, no significant difference was observed for the dry weight of stem compared with controls. It is suggested that use of Moso bamboo as an experimental material provides a new perspective for remediation of heavy metal contaminated soil owing to its high metal tolerance and greater biomass.

Adjuvant hyperbaric oxygen therapy in the treatment of hemodialysis patients with chronic osteomyelitis.

BACKGROUND: Hemodialysis dependence is an independent risk factor for hematogenous complication, including distant metastatic infection and osteomyelitis. Chronic osteomyelitis is a serious disease that fails to respond to aggressive medical and surgical treatment. Hyperbaric oxygen therapy has been proved to enhance bone and soft tissue healing in many studies. This article presents the preliminary result of hyperbaric oxygen therapy in hemodialysis-dependent patients with chronic osteomyelitis. MATERIALS AND METHODS: Ten hemodialysis dependent patients who were diagnosed with chronic diffuse osteomyelitis were treated prospectively with adjunctive hyperbaric oxygen therapy, in addition to aggressive surgical debridement and antibiotic treatment. RESULTS: The hyperbaric oxygen therapy averaged 20 daily sessions. Successful treatment was achieved in eight patients (80%). The mean length of treatment was 21 days. The preliminary results are comparable with other series. CONCLUSION: Hyperbaric oxygen is effective as an adjunct to aggressive medical and surgical treatment in chronic refractory osteomyelitis among hemodialysis-dependent patients.