[Role and mechanism of Cortex Moutan components in inhibiting production of toxic advanced glycation end products (AGEs)].

Advanced glycation end products(AGEs) can lead to many diseases such as diabetes and its complications. In this study, an in vitro non-enzymatic glycosylation reaction model-bovine serum albumin/methylglyoxal(BSA/MGO) reaction system was constructed and incubated with Cortex Moutan extract. High performance liquid chromatography(HPLC) and ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS/MS) were used to detect and identify the active components that inhibited the formation of AGEs in the co-incubation solution of Cortex Moutan extract and MGO, and differential components such as salvianan, paeoniside, benzoylpaeoniflorin, mudanpioside J, galloyloxypaeoniflorin, benzoyloxy-paeoniflorin, 5-hydroxy-3 s-hydroxymethyl-6-methyl-2,3-dihydro benzofuran, and galloylpaeoniflorin were screened out, which were inferred to be the potential active components of Cortex Moutan extract to capture MGO. In addition, BSA-glucose reaction system was performed to investigate the influence of different concentrations of Cortex Moutan extract(decoction concentrations: 40, 80, 120, 160, and 200 mg·mL~(-1)) on inhibiting the production of AGEs in vitro. The inhibitory effects of Cortex Moutan extract and the differential components galloylpaeoniflorin and benzoyl paeoniflorin on the production of AGEs in human umbilical vein endothelial cells(HUVECs) induced by high glucose was further evaluated. Cell apoptosis was observed by acridine orange and ethidium bromide(AO/EB) double fluorescence staining. The results showed that Cortex Moutan Cortex extract and its differential components had certain inhibitory effects on the formation of AGEs, and could reduce cell apoptosis. This study provided reference for the treatment of diabetic vascular complications by Cortex Moutan inhibiting the toxic AGEs.

Construction of a novel electrochemical biosensor based on a mesoporous silica/oriented graphene oxide planar electrode for detecting hydrogen peroxide.

A constant magnetic field (CMF) was used to arrange the orientation of graphene oxide (GO) which was modified on a self-made screen-printed electrode. We evaluated the efficiency of this method for potential analytical application towards the sensing of hydrogen peroxide (H2O2). Mesoporous silica (MS)-encapsulated horseradish peroxidase (HRP) was immobilized on the electrode with vertically arranged GO to construct an H2O2 sensor (denoted as CMF/GO/HRP@MS). The linear range of the response of the CMF/GO/HRP@MS sensor to H2O2 was 0.1-235 µM, and the detection limit was as low as 0.01 µM. The results demonstrated that the vertical arrangement of GO resulting from the CMF on the electrode surface could increase the electron transfer rate. The excellent selectivity and anti-interference ability of this sensor to H2O2 in physiological samples may be attributed to the synergistic effect of mesoporous silica, GO and constant magnetic field.

Antimicrobial and antioxidant activities of Flammulina velutipes polysaccharides and polysaccharide-iron(III) complex [corrected].

FVP is polysacchrides obtained from Flammulina velutipes. A polysacchride named FVP2 was isolated from FVP by DEAE cellulose-52 chromatography and Sephadex G-100 size-exclusion chromatography. FVP-Fe and FVP2-Fe were synthesized by neutralization of FeCl3 carbohydrate solution. The antibacterial and antifungal activities of FVP, FVP2, FVP-Fe, FVP2-Fe were investigated and their antioxidant effects on hydroxyl, 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide anion, 2,2'-azobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, reducing power, inhibition of malondialdehyde (MDA) were assessed in vitro. The results suggested that FVP-Fe and FVP2-Fe significantly suppressed the growth of bacteria Staphylococcus aureus, Escherichia coli, and Bacillus subtilis, and have relatively strong antioxidant activity to scavenge superoxide anion radical. In addition, FVP exhibited strong antioxidant activity to eliminate hydroxyl, DPPH, ABTS radicals, had high reducing power and inhibited the MDA production of health mice liver homogenate induced by auto-oxidation and Fe2+-H2O2 system.

Microbial transformation of curcumol by Aspergillus niger.

Curcumol is a representative index component for the quality control of the essential oil of Curcuma wenyujin Y.H. Chen et C. Ling, an antivirus and anticancer drug in China. Microbial transformation of curcumol (1) by Aspergillus niger AS 3.739 yielded two products. Their structures were elucidated as 3alpha-hydroxycurcumol (2) and 3alpha-(4'-methoxy-succinyloxy)-curcumol (3) by extensive spectroscopic methods including 2D-NMR and HRESI-MS. Among them, 3 is a new compound. Esterification of the substrate with succinic acid is a novel reaction in the field of microbial transformation of natural products. Compound 2, the major transformation product of 1, was a high regio- and stereo-specific hydroxylation product and showed significant antiviral effects.