Transformation of Tetracycline by Manganese Peroxidase from .

The negative impacts on the ecosystem of antibiotic residues in the environment have become a global concern. However, little is known about the transformation mechanism of antibiotics by manganese peroxidase (MnP) from microorganisms. This work investigated the transformation characteristics, the antibacterial activity of byproducts, and the degradation mechanism of tetracycline (TC) by purified MnP from .

Simultaneously detecting ethyl carbamate and its precursors in rice wine based on a pH-responsive electrochemical impedance sensor.

Intensive efforts have been made to diminish ethyl carbamate in fermentation products. The presented research demonstrated an approach to simultaneously detecting ethyl carbamate and its precursors including urea, citrulline and arginine with nano Mn(Ⅱ)O modified composite working electrode via electrochemical impedance spectroscopy. Adjusting sample solutions at certain pH value leads the differentiated priority of protonation from nitrogen group in the ethyl carbamate (EC) and its precursors.

Enrichment-Free Rapid Detection of Phthalates in Chinese Liquor with Electrochemical Impedance Spectroscopy.

A non-invasive real-time detection technique for phthalates in Chinese liquor is proposed in this paper. This method is based on the measurement of Faradaic impedance in the presence of a redox probe, [Fe(CN)], upon the absorption of phthalates to the graphene electrode surface. This absorption activity is according to the π-π stacking interactions between phthalates and the graphene working electrode which allows direct sampling and analyte preconcentration.

GUITAR-enhanced facile discrimination of aged Chinese Baijiu using electrochemical impedance spectroscopy.

The presented research demonstrated a method to evaluate aged Chinese Baijiu by measuring their electrochemical impedance spectrums (EIS) according to the distinctive colloidal impedance phenomena of verities' aged Baijiu. Graphite from the University of Idaho Thermolyzed Asphalt Reaction (GUITAR) electrode was employed for EIS data collection to achieve enhanced resolution. The obtained EIS Nyquist plots were simulated with the corresponding equivalent circuit to extract the numerical values of parameters which characterize the physicochemical properties of aged Baijiu.

Highly efficient and regioselective synthesis of dihydromyricetin esters by immobilized lipase.

Dihydromyricetin is the principle component of the Chinese herbal tea Teng-cha and a promising ingredient for functional food and nutraceuticals, but its low solubility limits its application potentials. This study explored enzymatic acylation of dihydromyricetin to improve its solubility in lipid systems. Acylation was achieved with several lipases with the synthesis of a major (>86%) product and a minor product.

Design and synthesis of the novel DNA topoisomerase II inhibitors: esterification and amination substituted 4'-demethylepipodophyllotoxin derivates exhibiting anti-tumor activity by activating ATM/ATR signaling pathways.

According to the structure-activity relationship, drug combination principle and bioisosterism, a series of the novel esterification and amination 4'-demethylepipodophyllotoxin derivates were rationally designed in order to discover the potential antitumor prodrug. And then these compounds were tested by the drug-topoisomerase II docking models for virtual screening. Thus, twelve target compounds were screened out and synthesized.

Actinobacillus succinogenes ATCC 55618 fermentation medium optimization for the production of succinic acid by response surface methodology.

As a potential intermediary feedstock, succinic acid takes an important place in bulk chemical productions. For the first time, a method combining Plackett-Burman design (PBD), steepest ascent method (SA), and Box-Behnken design (BBD) was developed to optimize Actinobacillus succinogenes ATCC 55618 fermentation medium. First, glucose, yeast extract, and MgCO(3) were identified to be key medium components by PBD.

Manipulation of heterogeneity product in 4'-demethylepipodophyllotoxin biotransformation process by using yeast extract as nitrogen source.

Manipulation of product heterogeneity was attempted by using yeast extract as nitrogen source in Alternaria alternata S-f6 transformation process of 4'-demethylepipodophyllotoxin. When the nitrogen source of NaNO(3) was replaced by yeast extract, the heterogeneity of biotransformation products was significantly varied from a single product (i.e.

Comparison of lipid content and fatty acid composition between Tuber fermentation mycelia and natural fruiting bodies.

A comparison of lipid content and fatty acid (FA) composition between Tuber fermentation mycelia and natural fruiting bodies indicates that the lipid content in Tuber fermentation mycelia is higher than that in fruiting bodies. Unsaturated FAs (particularly linoleic acid and oleic acid) were the predominant constituents in total FAs in both Tuber fermentation mycelia and fruiting bodies. A total of 23 FAs, including arachidonic, eicosapentaenoic, docosahexaenoic, and γ-linolenic acids, were first identified in the Tuber species.

Determination of the nucleosides and nucleobases in Tuber samples by dispersive solid-phase extraction combined with liquid chromatography-mass spectrometry.

A simple, fast and inexpensive method based on dispersive solid phase extraction (DSPE) combined with LC-MS was developed for simultaneous determination of 7 nucleosides and nucleobases (i.e., adenine, hypoxanthine, uridine, adenosine, guanine, guanosine, and inosine) in Tuber fruiting-bodies and fermentation mycelia.