Место издания:U.U. Uspanov Kazakh Research Institute of Soil Science and Agrochemistry of Kazakhstan web site at http://soil.kz/ Almaty
Первая страница:55
Последняя страница:60
Аннотация:A characteristic feature of lignin structures are their tendency to condensation reactions, which can lead to the formation of new stable C-C bonds. This lignin property with its high resistance to degradation divide it from other natural polymers and largely determines its action in biochemical processes, in-cluding the formation of humic acids. The determination of lignin in plants, soils and humus acids in-volved the alkaline oxidation with copper oxide at 1700 C under pressure in nitrogen environ-ment. Comparison of 13C-NMR spectra of native lignin preparations, isolated from different species of tree and herbaceous plants, with a spectrum of humic acid diagnosed that, the number of peaks at 102, 115, 119, 131, 152, 166 ppm also have a lignin genesis. Secondly, heterogeneous set of peaks in the spectra of different plants and, consequently, in the molecules of humic acids of different soils, must also be different. Thirdly, lignin of southern taiga trees is the source of more advanced in space mole-cules of humic acid with developed aliphatic part. Cinnamilic phenols from steppe plants form a spa-tially compact structure of Chernozem humic acids.
