1. Centre de Recherches sur les Macromolécules Végétales, CNRS, Affiliated with the Joseph Fourier University of Grenoble, B.P. 53, 38041 Grenoble Cedex 9, France, Institute of Chemistry, Slovak Academy of Sciences, SK-84238 Bratislava, Slovak Republic, and College of Environmental Science and Forestry, State University of New York, Syracuse, New York 13210