UNASSIGNED: 2-Amino-1-methyl-6-phenylimidazole [4,5-b] pyridine (PhIP), a heterocyclic amine (HAA), is found in meat products heated at high temperatures. However, PhIP is a mutagenic and potential carcinogenic compound. Cassiae semen, a type of medicine and food homology plant, is abundant in China and has been less applied for inhibiting heterocyclic amines.
UNASSIGNED: To investigate the inhibitory effect of cassiae semen extract on PhIP formation within a model system and elucidate the inhibitory mechanism, an ultrasonic-assisted method with 70% ethanol was used to obtain cassiae semen extract, which was added to a model system (0.6 mmol of phenylalanine: creatinine, 1:1). PhIP was analyzed by LC-MS to determine inhibitory effect. The byproducts of the system and the mechanism of PhIP inhibition were verified by adding the extract to a model mixture of phenylacetaldehyde, phenylacetaldehyde and creatinine.
UNASSIGNED: The results indicated that PhIP production decreased as the concentration of cassiae semen extract increased, and the highest inhibition rate was 91.9%. Byproduct (E), with a mass-charge ratio of m/z 199.9, was detected in the phenylalanine and creatinine model system but was not detected in the other systems. The cassiae semen extract may have reacted with phenylalanine to produce byproduct (E), which prevented the degradation of phenylalanine by the Strecker reaction to produce phenylacetaldehyde.
UNASSIGNED: Cassiae semen extract consumed phenylalanine, which is the precursor for PhIP, thus inhibiting the formation of phenylacetaldehyde and ultimately inhibiting PhIP formation. The main objective of this study was to elucidate the mechanism by which cassiae semen inhibit PhIP formation and establish a theoretical and scientific foundation for practical control measures.

BACKGROUND: Browning is the key problem hindering the industrialization of pear wine. The use of high-yield glutathione Saccharomyces cerevisiae in the fermentation of pear wine can inhibit browning. Glutathione reductase (GR) can ensure the reduction of glutathione. Spore immobilization of enzymes is a new technology. It is a new attempt to apply spore-immobilized GR in combination with high-yield glutathione S. cerevisiae to inhibit browning of pear wine.
RESULTS: Saccharomyces cerevisiae spore immobilization enzyme technology was used to immobilize GR in the spores of mutant S. cerevisiae dit1∆, osw2∆ and chs3∆ and wild-type S. cerevisiae. The enzyme activity of GR immobilized by chs3∆ spores was the highest of 3.08 U mg-1 min-1. The chs3∆ spore-immobilized GR had certain resistance to ethanol, citric acid, sucrose, glucose and proteinase K. Electron microscopy analysis showed that the spore wall of chs3∆ had moderate size holes, which might be the main reason why it immobilized GR with the highest enzyme activity. And the GR was immobilized between the prespore membrane and mannoprotein layer of the spore wall. When chs3∆ spore-immobilized GR (chs3∆-GR) was added to Dangshan pear wine fermented by high-yield glutathione S. cerevisiae JN32-9, the presence of chs3∆-GR could further protect amino acids, polyphenols and glucose from oxidation, thereby reducing the browning of the pear wine during storage by 47.32%.
CONCLUSIONS: GR immobilized by S. cerevisiae spores was effective in inhibiting the browning of pear wine. The method was simple, green and effective and did not increase the production cost of pear wine. © 2024 Society of Chemical Industry.

In this study, we mainly focused on predictable regularities of the red shift of ultraviolet spectra for β-phenylethylamine (PEA), NaCl and NaOH in aqueous solution. The absorption peaks of the UV spectra near 191 nm of NaCl, NaOH and PEA in aqueous solution moved in the direction of a red shift while the molar absorption coefficient at the peak increased regularly with the increasing solution concentration. These shifts were obtained for solutions with concentrations ranging from 3.68 to 1000 mmol/L for NaCl, from 0.762 to 2000 mmol/L for NaOH, and from 0.0515 to 8.91 mmol/L for PEA. The plots of the logarithm of the solution concentration for NaCl and PEA versus the absorbance at 191 nm and at the peak were linear, and the plots of the logarithm of the solution concentration for NaCl and PEA versus the wavelength at the peak (shifted from 191 nm) were also linear. In addition, the plots of the logarithm of the solution concentration for NaOH that ranged from 0.762 to 1.96 mmol/L versus the absorbance at 191 nm and at the peak were linear as well as the plots of the logarithm of the solution concentration for NaOH that ranged from 1.96 to 2000 mmol/L versus the wavelength at the peak. The slopes of the absorbance at 191 nm of PEA, NaCl and NaOH were somewhat similar to the absorbance at the peak separately, whereas the slopes of the wavelengths at the peak were different from them. Finally, in order to obtain the predictable regularity of the red shift of the UV spectrum for the mixture, 22 ternary mixtures were prepared. The results indicate that the inhibiting effect of hydroxide ions (OH-) caused the wavelength near 206 nm to remain unchanged when the solution concentration of NaOH in the mixture was more than 0.762 mmol/L.

The degradation of organic contaminants under high salinity condition is still a challenge for environmental remediation due to the inhibiting effect resulted from the side reactions between radicals and anions. Here, we demonstrate the non-radical oxidation process via peroxymonosulfate (PMS) activation by metal-free carbon catalyst for efficiently decomposing bisphenol A (BPA) in saline water. The nitrogen-doped graphitic carbon (NGC700) exhibits excellent catalytic activity for depredating BPA at acid and neutral pH. Based on the scavenger experiments and electron paramagnetic resonance (EPR) analyses, the mechanism of catalytic oxidation was elucidated as the non-radical pathway, and singlet oxygen was identified as the primary reactive species. Experiments on the influence of anions (5-500 mM) further show that the inhibiting effect was overcame due to the non-radical process. Interestingly, Cl- markedly facilitated the catalytic performance by generating HOCl in the catalytic process. The results highlight leveraging the non-radical pathway dominated by singlet oxygen to conquer the inhibitory effect of anions in NGC700/PMS system, which represents a crucial step towards environmental remediation under high salinity condition.

In view of the poor performance of biological nitrogen removal in saline wastewater treatment, nitrogen removal of anaerobic ammonium oxidation(ANAMMOX) with K+ addition was studied. The results showed that K+ addition could strengthen nitrogen removal performance. The effect of K+ on ANAMMOX process was mainly divided into four stages. In the adaptive phase(0-2 mmol·L-1), sudden addition of K+ destroyed the original equilibrium reaction, but ultimately ANAMMOX bacteria could adapt to the presence of K+. Because K+ had no obvious effects on anaerobic ammonia oxidation bacteria, the removal rates of NH4+-N and NO2--N slightly increased. In the ascension phase(2-8 mmol·L-1), K+ played a role in promoting anaerobic ammonia oxidation biological systems, with increasing concentration of K+, the removal rates of NH4+-N and NO2--N significantly increased. In the stabilization phase(8-20 mmol·L-1), the nitrogen removal rate decreased, but was still higher than the control without K+ addition. In the inhibition phase(more than 20 mmol·L-1), K+ largely inhibited anaerobic ammonia oxidation, and its denitrification efficiency was lower than 0 mmol·L-1. In the whole cycle, when the concentration of K+ was 8 mmol·L-1, it achieved the best effect, the average removal rates of NH4+-N and NO2--N were 89.24% and 84.87%, and NRR was 1.113 kg·(m3·d)-1.

The invasive and infiltrative nature of tumor cells leads to the poor prognosis of glioma. Currently, novel therapeutic means to eliminate the tumor cells without damaging the normal brain tissue are still strongly demanded. Significant attentions had been paid to stem cell-based therapy and neural stem cell (NSC) had been considered as one of the efficient delivery vehicles for targeting therapeutic genes. However, whether the NSCs could directly affect glioma cells remains to be seen. In this study, both rat and human glioma cells (C6 and U251) were co-cultured with normal rat embryonic NSCs directly or in-directly. We found the survival, proliferation, invasion and migration of glioma cells were significantly inhibited, while the differentiation was not affected in the in vitro co-culture system. In nude mice, although no significant difference was observed in the tumor growth, survival status and time of tumor-bearing mice were significantly promoted when U251 cells were subcutaneously injected with NSCs. In coincidence with the suppression of glioma cell growth in vitro, expression of mutant p53 and phosphorylation of AKT, ERK1/2 decreased while the level of caspase-3 increased significantly. Our results suggested that normal NSCs could possess direct anti-glioma properties via inhibiting the glioma cell viability, proliferation, invasion and migration. It could be a very promising candidate for glioma treatment.

Co-gasification of rice straw (RS) and Shenfu bituminous coal (SF) was conducted in a thermogravimetric analyzer (TGA) to explore the effects of gasification temperature and blend ratio on reactivity characteristics and synergy behaviours of co-gasification. Moreover, the relationship between the synergy and the K/Ca transformation in co-gasification was studied using flame atomic absorption spectrum (FAAS) and in-situ heating stage microscope. The results showed that the whole reactivities increased with increasing RS proportion and gasification temperature. The transformation of water-soluble and ion-exchanged (ws-ie) calcium was enhanced in whole co-gasification and the ws-ie potassium transformation was obviously inhibited in mid-late reaction. Hence, synergy behaviours were synthetically determined by the enhancement of Ca deactivation and the strengthening of K catalysis. The inhibiting effect was occurred in initial co-gasification and was converted to the synergistic effect at a characteristic conversion, which decreased with increasing RS proportion and decreasing gasification temperature.

Co-gasification of coal char and biomass char was conducted to investigate the interactions between them. And random pore model (RPM) and modified random pore model (MRPM) were applied to describe the gasification behaviors of the samples. The results show that inhibiting effect was observed during co-gasification of corn stalk char with Hulunbeier lignite coal char, while synergistic effects were observed during co-gasification of corn stalk char with Shenmu bituminous coal char and Jincheng anthracite coal char. The inhibiting effect was attributed to the intimate contact and comparable gasification rate between biomass char and coal char, and the loss of the active form of potassium caused by the formation of KAlSiO4, which was proved to be inactive during gasification. While the synergistic effect was caused by the high potassium content of biomass char and the significant difference of reaction rate between coal char and biomass char during gasification.