According to active groups synergetic catalysis principle, a novel phosphodiester receptor 1-( N -guanidinoethyl)-4-( N -hydroxyethyl)-piperazidine hydrochloride was firstly synthesized and the preliminary studies of its DNA cleavage activity. It is characterized and confirmed by methods as 1 H NMR and 13C NMR. A “couple hardness with softness” piperazidine is designed to connect guanidinium group and hydroxyl group; The reserch was showed that the best cleaving conditions was 7.2 in pH; Cleaving DNA by the compound reaction was oxidation process that were proved through the free radicals quenches experiments; The compound can cleaved the pUC 19 DNA by phospholipid transferance was proved by BDNPP.
Eco-friendly enzymatic-recycling has been widely utilized in tackling plastic pollution. However, the limited activity on the polyethylene terephthalate (PET) degradation product mono-hydroxyethyl terephthalate (MHET) leads to the formation of heterogeneous hydrolysis products, resulting in PET downcycling. Herein, by applying a dual-function PET hydrolase Is PETase PA with balanced PET and MHET degradation efficiency, an effective PET hydrolysis process was developed to enhance the terephthalic acid (TPA) product purity. Firstly, the impact of pH on the catalytic activity of Is PETase PA revealed that the pH reduction caused by TPA generation hindered the complete conversion of MHET to TPA. Further investigation of the catalytic mechanism showed that the pH-induced protonation of H208 in the catalytic triad destabilized the interaction between Is PETase PA and MHET. Thus, by introducing pH regulation strategy on the bifunctional Is PETase PA , the single-enzyme process could achieve high-purity TPA recovery (>99 %). Overall, this work ensured the high-quality PET enzymatic-recycling for effectively addressing plastic pollution.
Novel soybean-oil-based (SBO-based) epoxy acrylate (EA) resins were developed via ring-opening reaction of epoxidized soybean oil (ESO) with hydroxyethyl methacrylated maleate (HEMAMA) precursor, a synthesized unsaturated carboxylic acid having two active C═C groups and a side methyl group. Experimental conditions for the synthesis of the precursor and the SBO-based EA (ESO-HEMAMA) product were studied, and their chemical structures were confirmed by FT-IR, 1H NMR, 13C NMR, and gel permeation chromatography. Subsequently, the volatility of HEMAMA was studied and compared with acrylic acid (AA). Furthermore, gel contents and ultimate properties of the UV-cured ESO-HEMAMA resins were investigated and compared with a commercial acrylated ESO (AESO) resin. At last, UV-curing behaviors of the SBO-based EA resins were determined by real-time IR. It was found that the HEMAMA precursor showed much lower volatility than AA, and the optimal pure ESO-HEMAMA resin possessed a C═C functionality up to 6.02 per ESO and biobased content of 65.4%. Meanwhile, the obtained ESO-HEMAMA biomaterials exhibited much superior properties as compared to the AESO resin. For instance, the obtained pure ESO-HEMAMA material possessed a storage modulus at 25 °C of 1.00 GPa, glass transition temperature (Tg) of 70.1 °C, and tensile strength and modulus of 13.4 and 592.1 MPa, which were 9.4, 3.6, 6.9, and 15.7 times the values of the pure AESO material, respectively. The resulting biomaterial with 30% of hydroxyethyl methacrylate diluent even reached a tensile strength of 28.4 MPa and Tg of 89.0 °C. Therefore, the developed SBO-based EA resins are very promising for applications in UV-curable coatings.
危险品化学品经营许可证（带存储）