The existence of calcium and nickel in crude oil causes serious damage to oil processing equipment and reduces the quality of products. These metals are extremely hard to remove as they exist in form of stable oil-soluble complexes. If they could be removed during the electric desalination process, economic benefits will be greatly improved. The current study thus aimed to seek clean and non-corrosive demetallizing agents to chelating calcium and nickel during the electric desalination process of crude oil. Two different N-substituted pyridines based core-shell materials of P2VP@SiO 2 (2-vinylpyridine) and P4VP@SiO 2 (4-vinylpyridine) were first prepared, and their metal adsorption capacity and selectivity were explored and compared. The structure and mass grafting ratios (GR) of two materials were determined by FT-IR, TGA, elemental analysis (EA), GPC, SEM and TEM. The GR of P2VP@SiO 2 and P4VP@SiO 2 under different monomer concentrations, reaction temperature and duration were studied. In addition, the effects of various process conditions on nickel and calcium removal rates using the prepared P2VP@SiO 2 and P4VP@SiO 2 were investigated. It was worth noting that due to the difference in N substitution positions, for the same pyridine functional group, P2VP@SiO 2 exhibited more stable adsorption selectivity, while adsorption capacity of P4VP@SiO 2 for calcium and nickel is much better than P2VP@SiO 2 . The calcium and nickel removal rates by P4VP@SiO 2 reached 61.3% and 67.2%, respectively. Briefly, P4VP@SiO 2 could be used as a highly efficient demetallizing agent for removing calcium and nickel in crude oil, with high metal adsorption capacity.
A concise and efficient approach was developed for the synthesis of mono-substituted and di-substituted pyrimidines products via palladium-catalyzed amination of chloro-substituted 5-nitropyrimidines and amines. This synthetic methodology can produce various di-substituted pyrimidines in high yields with good functional group tolerance, and provide a complementary tool for the syntheses of important intermediates of nucleosides and purines with bioactivities.
Chao Yang,Haojie Cai,Xinying Zhu,Lei Zhang,Jing Li
Xanthine oxidoreductase (XOR) and uric acid transporter 1 (URAT1) are two most widely studied targets involved in production and reabsorption of uric acid, respectively. Marketed drugs almost target XOR or URAT1, but sometimes, single agents might not achieve aim of lowering uric acid to ideal value in clinic. Thus, therapeutic strategies of combining XOR inhibitors with uricosuric drugs were proposed and implemented. Based on our initial work of virtual screening, A and B were potential hits for dual-targeted inhibitors on XOR/URAT1. By docking A / B with XOR/URAT1 respectively, compounds I1-7 were designed to get different degree of inhibition effect on XOR and URAT1, and I7 showed the best inhibitory effect on XOR (IC 50 = 0.037 ± 0.001 μM) and URAT1 (IC 50 = 546.70 ± 32.60 μM). Further docking research on I7 with XOR/URAT1 led to the design of compounds II with the significantly improved inhibitory activity on XOR and URAT1, such as II11 and II15 . Especially, for II15 , the IC 50 of XOR is 0.006 ± 0.000 μM, superior to that of febuxostat (IC 50 = 0.008 ± 0.000 μM), IC 50 of URAT1 is 12.90 ± 2.30 μM, superior to that of benzbromarone (IC 50 = 27.04 ± 2.55 μM). In acute hyperuricemia mouse model, II15 showed significant uric acid lowering effect. The results suggest that II15 had good inhibitory effect on XOR/URAT1, with the possibility for further investigation in in-vivo models of hyperuricemia.
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