Phenolic polymers synthesized by reactions of p-benzoquinone with 15N-labelled protein or(15NH4)2SO4 were studied by using 15N CP-MAS NMR technique in combination with chemical approaches.Results showed that more than...Phenolic polymers synthesized by reactions of p-benzoquinone with 15N-labelled protein or(15NH4)2SO4 were studied by using 15N CP-MAS NMR technique in combination with chemical approaches.Results showed that more than 80% of nitrogen in quinone-protein polymers was in the form of amide with some present as aromatic and/or aliphatic alone and less than 10% of nitrogen occurred as heterocyclic N.The nitrogen distribution in the non-hydrolyzable residue of the quinone-protein polymers was basically similar to that of soil humic acid reported in literature with the exception that a higher proportion of N as heterocyclic N and aromatic amine and a lower proportion of N as amide and aliphatic amine were found in the former than in the latter. More than 70% of total nitrogen in quinones(NH4)2SO4 polymer was acid resist ant,of which about 53% occurred as pyrrole,nitrile and imino type N.The possible roles of the reactions of phenols or quinones with proteins in the formation of humic acid,especially the non-hydrolyzable nitrogen in humic acid,are discussed.展开更多
文摘Phenolic polymers synthesized by reactions of p-benzoquinone with 15N-labelled protein or(15NH4)2SO4 were studied by using 15N CP-MAS NMR technique in combination with chemical approaches.Results showed that more than 80% of nitrogen in quinone-protein polymers was in the form of amide with some present as aromatic and/or aliphatic alone and less than 10% of nitrogen occurred as heterocyclic N.The nitrogen distribution in the non-hydrolyzable residue of the quinone-protein polymers was basically similar to that of soil humic acid reported in literature with the exception that a higher proportion of N as heterocyclic N and aromatic amine and a lower proportion of N as amide and aliphatic amine were found in the former than in the latter. More than 70% of total nitrogen in quinones(NH4)2SO4 polymer was acid resist ant,of which about 53% occurred as pyrrole,nitrile and imino type N.The possible roles of the reactions of phenols or quinones with proteins in the formation of humic acid,especially the non-hydrolyzable nitrogen in humic acid,are discussed.
