Abstract To illuminate changes in the secondary metabolic spectrum and hypoglycemic activity between Rose roxburghii fruit fermented (RRFF) by Chinese traditional distiller’s yeast and R. roxburghii fruit (RRF) using UPLC–MS/MS and streptozotocin-induced diabetic mice. Secondary metabolomics in the RRFF apparently differs from those in RRF; 32 pentacyclic triterpenoids were identified first, and ursolic acid-substituted roxburix acids were found to be the marker compounds. Testing of HepG2 cells indicated that RRFF had good glucose consumption capacity. Additionally, fasting blood glucose levels, glucose tolerance tests, plasma insulin levels and insulin resistance in diabetic mice indicated that RRFF was better than RRF. More importantly, RRFF exhibited good structure in pancreatic tissue. These results indicate that the fermentation process is beneficial for increasing the content of triterpenoids and enhancing hypoglycemic activity. Traditional fermentation with Chinese traditional distiller’s yeast can provide a way to expand the application of nutritious fruits with short shelf life.

Electrosynthesis of dimethyl carbonate (DMC) from methanol and carbon monoxide using an Cu(phen)Cl2 catalyst was achieved at room temperature and atmospheric pressure. The catalytic activity of the ligand 1,10-phenanthroline (phen) and the catalytic system were analyzed. The IR characterization results for the complex catalyst showed that copper ions were coordinated by nitrogen atoms of phen. In addition, the effects of the influencing factors, such as reaction time (t), reaction temperature (T) and the surface area of the working electrode (SWE) were studied.

The turbulent flow in a Kenics Static Mixer (KSM) was intensified under the mutual-coupling effect between the twisted leaves and the tube-wall. In order to understand the intrinsic features of turbulent flow in KSM, the Hilbert-Huang Transform based on Empirical Mode Decomposition were first introduced to describe the time-frequency features of the pressure fluctuation. The Hilbert spectra of pressure fluctuation time series were quantitatively evaluated under different Reynolds numbers, and different radial and axial positions, respectively. The experimental results showed that: the fluctuation frequencies of pressure signals in a KSM were mainly distributed below 40 Hz, and more than 68% of the energy of signals is concentrated within 10 Hz. Compared with the other IMFs, the pressure component of C6 in the range of 7.82~15.63 Hz has the maximum fluctuation energy ratio. As the flow rate increases, the energy of fluctuation of fluid micelles and the proportion of low-frequency energy increases. The pressure fluctuation with higher energy ratio of low frequency (0~10 Hz) had lower amplitudes at r/R=0.3 because of the core of forced vortex. Nevertheless, the effect of the free vortex was that the pressure fluctuation with lower energy ratio of low frequency had higher amplitudes at r/R=0.8. The higher amplitudes of pressure fluctuation at cross sections of CS3 (z=420 mm) and CS5 (z=620 mm) proved that the transitions between the adjacent mixing element had better mixing performance.