Abstract
A scanning tunneling microscope (STM) was used to observe the temporal formation and organization of dehydrogenative polymer (DHP) synthesized from coniferyl alcohol. The images obtained elucidate this structure for the first time. The structure of DHP, as seen from STM images, shows long-range order. It appears that DHP consists of building units or modules assembled into larger assemblies called supermodules. Supermodules are interconnected into the overall lattice-like polymer structure with or without spherical regions. One module consists of about 20 monomers, while the supermodule contains about 500 monomers. Calculated molecular weights for modules and supermodules agree with DHP molecular weight distribution peaks. Samples prepared at two different pH values, 6.4 and 7.6, have the same characteristics. The results presented demonstrate that the process of lignification, even in in vitro conditions, is highly ordered, and as such contribute to our understanding of the structure of lignin, a significant constitutive and functional element of cell walls.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Atalla R. H., Agarwal U. P. Raman microprobe evidence for lignin orientation in the cell walls of native woody tissue. Science. 1985 Feb 8;227(4687):636–638. doi: 10.1126/science.227.4687.636. [DOI] [PubMed] [Google Scholar]
- Freudenberg K. Lignin: Its Constitution and Formation from p-Hydroxycinnamyl Alcohols: Lignin is duplicated by dehydrogenation of these alcohols; intermediates explain formation and structure. Science. 1965 Apr 30;148(3670):595–600. doi: 10.1126/science.148.3670.595. [DOI] [PubMed] [Google Scholar]
- Hwang R. An approach to lignification in plants. Biochem Biophys Res Commun. 1982 Mar 30;105(2):509–514. doi: 10.1016/0006-291x(82)91464-4. [DOI] [PubMed] [Google Scholar]
- Lewis N. G., Yamamoto E. Lignin: occurrence, biogenesis and biodegradation. Annu Rev Plant Physiol Plant Mol Biol. 1990;41:455–496. doi: 10.1146/annurev.pp.41.060190.002323. [DOI] [PubMed] [Google Scholar]
- Nozu Y. Studies on the biosynthesis of lignin. 3. Dehydrogenative polymerization of coniferyl alcohol by peroxidase. J Biochem. 1967 Nov;62(5):519–530. doi: 10.1093/oxfordjournals.jbchem.a128701. [DOI] [PubMed] [Google Scholar]