Here, molecular docking simulation was used to predict and compare interactions between a recombinant Trametes sp. C30 laccase from Saccharomyces cerevisiae and four aflatoxins (AFB 1 , AFB 2 , AFG 1 , and AFG 2 ) as well as their degradation at a molecular level. The computational result of docking simulation indicates that each of the aflatoxins tested can interact with laccase with a binding ability of AFB 1 >AFG 2 >AFG 1 >AFB 2 . Simultaneously, it also demonstrated that aflatoxin B 1 , B 2 , G 1 , G 2 may interact near the T1 copper center of the enzyme through H-bonds and hydrophobic interactions with amino acid residues His481 and Asn288; His481; Asn288, and Asp230; His481 and Asn288. Biological degradation test was performed in vitro in the presence of a recombinant laccase. Degradation increased as incubation time increased from 12 to 60 hr and the maximum degradation obtained for AFB 1 , AFB 2 , AFG 1 , and AFG 2 was 90.33%, 74.23%, 85.24%, and 87.58%, respectively. Maximum degradation of aflatoxins was determined with a total activity 3 U laccase at 30°C in 0.1 M phosphate buffer, pH 5.7 after 48-hr incubation. The experimental results are consistent with that of docking calculation on the biological degradation test of four aflatoxins by laccase.Practical Application: In this study, the degradation efficiencies of laccase for B and G series of aflatoxins were determined by computer simulation and verified by performing in vitro experiments. It can provide reference for rapid screening of aflatoxin degradation-related enzymes.

A B S T R A C T Triclosan, a widely used antimicrobial agent, can increase colitis-associated colon tumorigenesis, and induce liver fibrosis and cancer in mice through mechanisms which may be relevant in humans. In this study, an analytical method using gas chromatography-mass spectrometry (GC-MS) and high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS) was developed to measure dioxins and chlorinated derivatives from triclosan in the presence of active chlorine in seawater matrix. Formation yields of dioxins and chlorinated triclosans were assessed at different initial precursor concentrations under dark and UV light irradiation conditions. Results showed that triclosan was rapidly transformed to its chlorinated derivatives, i.e. tetraclosans and pentaclosans, of which the formation yields peaked after 1 h of reaction. UV light was the key factor to promote the formation of dioxins. With the same initial triclosan/active chlorine ratio, the highest yield of dioxins was observed with lower initial concentrations of triclosan under UV irradiation. Five dioxins, including 2, 1,2,2,3,1,2,3,and 2,3,7, were identified and quantified. 2,3,7,, the most toxic dioxin, was firstly reported as the phototransformation product of triclosan in aquatic solution. Results presented here are useful for a comprehensive understanding of the fate and toxicity of triclosan in contaminated waters.

The study aimed to explore the metabolic changes of adipose tissue of hyperlipidemia rats with hawthorn ethanol extracts (HEE) consumption by a high‐throughput metabolomics approach. HEE were mainly composed of chlorogenic acid, hyperoside, isoquercitrin, rutin, vitexin, quercetin, and apigenin by HPLC analysis. HEE administration significantly lowered levels of the total cholesterols, triglyceride and low‐density lipoprotein cholesterol as compared to the high‐fat diet model. Gas chromatography‐mass spectrometry was used to identify adipose metabolite profiles. Numerous endogenous molecules were altered by high‐fat diet and restored following intervention of HEE. Metabolites elevated in adipose, including l‐threonine, aspartic acid, glutamine, mannose, inositol and oleic acid, were detected after HEE consumption. Fifteen metabolites were identified as potential biomarkers of hyperlipidemia. Pathway analysis showed that most of the discriminant metabolites were included in fatty acid biosynthesis, galactose metabolism, biosynthesis of unsaturated fatty acids, arginine and proline metabolism, alanine, aspartate and glutamate metabolism, glycerolipid metabolism and steroid biosynthesis. These metabolites and metabolic networks we found offer new insights into exploring the molecular mechanisms of lipid‐lowering of hawthorn ethanol extracts on adipose tissue of rats. Practical Application There was a very high proportion of hyperlipidemia in China. Hawthorn is attracting increasing attention owing to their health benefits, low toxicity, effectiveness and might be suitable for long‐term use.

Dioxin exposure tends to accumulate in adipose tissue and alters metabolism in mammals.