The adsorption behavior ofp-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature. Experimental r...The adsorption behavior ofp-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature. Experimental results indicated that the equilibrium adsorption data of the four polymeric adsorbents fitted well in the Freundlich isotherm. The adsorption capacity of multi-functional polymeric adsorbent NJ-99 was the highest, which might be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of aminobenzoic acid. The adsorption capacity of o-aminobenzoic acid onto any adsorbent was higher than p-aminobenzoic acid. Thermodynamic studies suggested the exothermic, spontaneous physical adsorption process. Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetics model and the intraparticle mass transfer process was the rate-controlling step.展开更多
A series of extraction equilibrium experiments for aminobenzoic acid were carried out. Tri n octylamine (TOA) and tributyl phosphate (TBP) were selected as complexing agents. 1 Octanol and kerosene were selected ...A series of extraction equilibrium experiments for aminobenzoic acid were carried out. Tri n octylamine (TOA) and tributyl phosphate (TBP) were selected as complexing agents. 1 Octanol and kerosene were selected as diluents. The effects of extractant concentration and pH on the distribution ratio were discussed in detail. It was found that there are ion pair association and hydrogen bond complexing in the extraction. Expressions of the equilibrium distribution for different solvent systems are proposed. The precision of the models is satisfactoy. 展开更多
Aromatics have a broad application in our everyday life ranging from plastics, coatings and fibres, to food and pharmaceuticals. To date the bulk of these aromatics is derived from naphtha-based pet-rochemistry. Howev...Aromatics have a broad application in our everyday life ranging from plastics, coatings and fibres, to food and pharmaceuticals. To date the bulk of these aromatics is derived from naphtha-based pet-rochemistry. However, recent progress in the fermentative production of metabolites using renew-able resources and engineered microbes has enabled the production of bio-precursors, such as 4-amino benzoic acid (pABA) and 2-amino benzoic acid (oABA). In this work we explored the feasibility of Sandmeyer reactions for the conversion of pABA to terephthalic and oABA salicylic acid, providing two very important platform chemicals for the chemical and pharmaceutical industries. We could demonstrate that both acids can be obtained from the amino benzoic acids derived from the shikimate pathway in microbes and plants. Good conversions could be achieved using Sandmeyer reactions at mild conditions with biodegradable reagents and without organic solvents.展开更多
The dependence of electronic absorption spectra antimicrobial property on the substituent position was investigated using three Schiff bases derived from salicylaldehyde and isomeric aminobenzoic acids in three solven...The dependence of electronic absorption spectra antimicrobial property on the substituent position was investigated using three Schiff bases derived from salicylaldehyde and isomeric aminobenzoic acids in three solvents of different polarities. The absorption maxima in all three solvents exhibited dependence on the position of substituent with the absorption maxima undergoing a red shift as solvent polarity increased. The in vitro antibacterial activity of the compounds against some clinically important bacteria namely Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), Enterococcus feacalis (ATCC 29212) was determined in N,N”-dimethylformamide and 1,4-dioxane using the agar dilution method. The results revealed that the ortho and meta substituted Schiff bases exhibited better antimicrobial activity in the non-polar solvent.展开更多
Glassy carbon electrode, which is used to electrochemically determine the content of buformin, is modified with an electropolymerized film of p-aminobenzoic acid in pH 7.0 acetate buffer solution （ABS）. The polymer ...Glassy carbon electrode, which is used to electrochemically determine the content of buformin, is modified with an electropolymerized film of p-aminobenzoic acid in pH 7.0 acetate buffer solution （ABS）. The polymer showed an excellent electrocatalytic activity for the reduction of buformin. In pH 7.0 ABS, the cathodic peak current increased linearly over three concentration intervals of buformin, and the detection limit （S/N=3） was 2.0 ×10^9 g/mL. The method was successfully applied to directly determine buformin in tablets with standard addition recoveries of 95.8 102.5%. The proposed method is simple, cheap and highly efficient.展开更多
基金Project supported by the National Key Technology Research and Development Program of China(No.2006BAC02A15)Opening Foundation of Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection of China(No.JLCBE05006)the Qinglan Project of Jiangsu Province
文摘The adsorption behavior ofp-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature. Experimental results indicated that the equilibrium adsorption data of the four polymeric adsorbents fitted well in the Freundlich isotherm. The adsorption capacity of multi-functional polymeric adsorbent NJ-99 was the highest, which might be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of aminobenzoic acid. The adsorption capacity of o-aminobenzoic acid onto any adsorbent was higher than p-aminobenzoic acid. Thermodynamic studies suggested the exothermic, spontaneous physical adsorption process. Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetics model and the intraparticle mass transfer process was the rate-controlling step.
基金the National Natural Science Foundationof China (No.2 9836 130
文摘A series of extraction equilibrium experiments for aminobenzoic acid were carried out. Tri n octylamine (TOA) and tributyl phosphate (TBP) were selected as complexing agents. 1 Octanol and kerosene were selected as diluents. The effects of extractant concentration and pH on the distribution ratio were discussed in detail. It was found that there are ion pair association and hydrogen bond complexing in the extraction. Expressions of the equilibrium distribution for different solvent systems are proposed. The precision of the models is satisfactoy.
文摘Aromatics have a broad application in our everyday life ranging from plastics, coatings and fibres, to food and pharmaceuticals. To date the bulk of these aromatics is derived from naphtha-based pet-rochemistry. However, recent progress in the fermentative production of metabolites using renew-able resources and engineered microbes has enabled the production of bio-precursors, such as 4-amino benzoic acid (pABA) and 2-amino benzoic acid (oABA). In this work we explored the feasibility of Sandmeyer reactions for the conversion of pABA to terephthalic and oABA salicylic acid, providing two very important platform chemicals for the chemical and pharmaceutical industries. We could demonstrate that both acids can be obtained from the amino benzoic acids derived from the shikimate pathway in microbes and plants. Good conversions could be achieved using Sandmeyer reactions at mild conditions with biodegradable reagents and without organic solvents.
文摘The dependence of electronic absorption spectra antimicrobial property on the substituent position was investigated using three Schiff bases derived from salicylaldehyde and isomeric aminobenzoic acids in three solvents of different polarities. The absorption maxima in all three solvents exhibited dependence on the position of substituent with the absorption maxima undergoing a red shift as solvent polarity increased. The in vitro antibacterial activity of the compounds against some clinically important bacteria namely Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), Enterococcus feacalis (ATCC 29212) was determined in N,N”-dimethylformamide and 1,4-dioxane using the agar dilution method. The results revealed that the ortho and meta substituted Schiff bases exhibited better antimicrobial activity in the non-polar solvent.
基金supported by the System Foundation of Guangdong Food and Drug Administration and Guangdong Institute for Drug Control (nos. SN20106537, ZA20101509)
文摘Glassy carbon electrode, which is used to electrochemically determine the content of buformin, is modified with an electropolymerized film of p-aminobenzoic acid in pH 7.0 acetate buffer solution （ABS）. The polymer showed an excellent electrocatalytic activity for the reduction of buformin. In pH 7.0 ABS, the cathodic peak current increased linearly over three concentration intervals of buformin, and the detection limit （S/N=3） was 2.0 ×10^9 g/mL. The method was successfully applied to directly determine buformin in tablets with standard addition recoveries of 95.8 102.5%. The proposed method is simple, cheap and highly efficient.
