The crystal structure of a trimeric lignin model 1 presenting the characteristic pattern of biphenyl (5,5') and aryl-alkyl-ether (beta-O-4) linkages has been determined. The crystal system is triclinic and the crystallographic unit cell consists of two monomeric molecules. These results are compared with crystal data from the literature of simple models of the 5,5' and beta-O-4 structure type. The availability of a terminal aldehyde function on the model affords some interesting intermolecular interactions by weak hydrogen bonding which controls the conformation of the molecule and the aromatic ring orientation in particular; an unexpected cisoïd conformation of the biaryl unit is observed based on the 64.4 degrees value found for the torsion angle between the two 5,5' aromatic rings.
Zinc(") complexes of N-pyridylcinnamides (H, m-OCH3, p-OCH, and /?-OH derivatives) were studied by spectrophotometric methods in aprotic media, and represent a chemical model inhibition by cinnamides of coniferyl alcohol dehydrogenase (CAD), a zinc enzyme involved in the lignilication process. The complexation of Npyridylcinnamide and m-methoxy-N-pyridylcinnamide with zinc ion is effected according to a 1 : 1 stoichiometry (ML), whereas a two-step equilibrium ( M + L = MLI='.ML*) is preferred with p-methoxy and p-hydroxy compounds. These ligands are mainly bonded through the carbonyl oxygen atom and the nitrogen of the pyridyl ring. Molar absorptivities for these complexes, not directly available, were calculated from analysis of the experiemental data. The UV complexation results are also supported by the stoichiometry of the complexes, which were synthesized and characterized.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.