Piperacillin is a polar organic substance, and can reduce the interfacial tension of oil and water when dissolved in water. In this study, changes in dichloromethane–water interfacial tensions and microdroplet sizes during piperacillin synthesis from an aqueous solution of ampicillin and dichloromethane solution of 4-ethyl-2,3-dioxo-1-piperazine carbonyl chloride (EDPC) were observed using a pendent drop technique and a coaxial ring tube system with embedded high-speed camera, respectively. It was found that the rapid N -acylation reaction caused the piperacillin at the interface to synthesize rapidly and diffuse out slowly, resulting in the interfacial tension decreased from 19.5 mN·m −1 to 7.2 mN·m −1 rapidly and then increased slowly as the concentrations of ampicillin and EDPC were 0.05 mol·L −1 and 0.1 mol·L −1 . Meanwhile, the increase in the concentration of EDPC increased the peak concentration of piperacillin at the interface, and the addition of ethyl acetate to the ampicillin solution promoted mass transfer and reduced the aggregation of piperacillin effectively. During synthesis, the interfacial tension decreased, leading to a change in droplet sizes in the micro-reaction system. The two-phase reaction was carried out in a coaxial ring tube, with ampicillin and EDPC solutions as continuous and dispersed phases, respectively. The reaction reduced the dripping flow area, and the addition of ethyl acetate to the ampicillin solution slightly affected the division of the flow pattern. Under the same flow conditions, the droplet sizes of the reaction group were smaller than those of the no reaction group. The experimental results demonstrated that the increase of the continuous phase, decrease in the dispersed phase flow rate, or increase in EDPC concentration making droplet sizes smaller, and the addition of ethyl acetate slightly affected droplet sizes. These findings are important for the design and optimization of piperacillin synthesis reactors.
In this work, ring-like anhydrides (C4, C5, and C6) with different sizes and succinic anhydrides (C4, C10, C12, C14, and C16) with different side chain lengths were used to modify bovine bone gelatin (BBG) and cold-water fish skin gelatin (CFG), and the effect of acylated gelatins on fish oil-loaded emulsions stability was explored. The results showed that the degree of N -acylation decreased with increased ring sizes or side chain lengths, and the surface hydrophobicity of acylated gelatins increased with increased anhydride carbon numbers. Acylated CFGs had higher droplet stability and lower liquid-gel transition time than acylated BBGs. Only BBG-C12 had a slight increase on the creaming stability among these acylated gelatins. These results demonstrated that the gelatins could be modified by all the anhydrides and their emulsion stabilization ability was dependent on the gelatin type and anhydride structure. The results could be beneficial for protein-based emulsifier development and application.
Jing Yang,Xujiao Tang,Qingqing Wu,Panpan Ren,Yishu Yan,Wei Liu,Chun Pan
Heparin has shown benefits in severe acute pancreatitis (SAP) therapy, but the underlying mechanisms were unknown. Extracellular high-mobility group protein-1 (HMGB-1) has been regarded as a central mediator contributing to inflammation exacerbation and disease aggravation. We hypothesized heparin attenuated the disease by targeting HMGB-1-related pathways. In the present study, the possible therapeutic roles of heparin and its non-anticoagulant derivatives, 6-O-desulfulted heparin and N-acylated-heparin, were determined on mouse models induced by “Two-Hit” of L-arginine. The compounds exhibited potent efficiency by substantially decreasing the pancreatic necrosis, macrophage infiltration, and serum inflammatory cytokine (IL-6 and TNF-α) concentration. Moreover, they greatly reduced the rapidly increasing extracellular HMGB-1 levels in the L-arginine injured pancreases. As a result, multiple organ failure and mortality of the mice were inhibited. Furthermore, the drugs were incubated with the RAW264.7 cells activated with damaged pancreatic tissue of SAP mice in vitro. They were found to inhibit HMGB-1 transfer from the nucleus to the plasma, a critical step during HMGB-1 active secretion from macrophages. The results were carefully re-examined with a caerulein and LPS induced mouse model, and similar results were found. The paper demonstrated heparin alleviated SAP independent of the anti-coagulant functions. Therefore, non-anticoagulant heparin derivatives might become promising approaches to treat patients suffering from SAP.Keywords:heparin;severe acute pancreatitis;HMGB-1;macrophage
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