In: Lignin ISBN: 978-1-53614-769-8 Editors: Fachuang Lu and Fengxia Yue © 2019 Nova Science Publishers, Inc. Chapter 4 SOLUTION-STATE MULTIDIMENSIONAL NMR OF LIGNINS: APPROACHES AND APPLICATIONS Yuki Tobimatsu 1,* , Toshiyuki Takano 2 , Toshiaki Umezawa 1 and John Ralph 3 1 Research Institute for Sustainable Humanosphere, Kyoto University, Japan 2 Graduate School of Agriculture, Kyoto University, Japan 3 Department of Biochemistry, and the Department of Energy’s Great Lakes Bioenergy Research Center, The Wisconsin Energy Institute, University of Wisconsin-Madison, US ABSTRACT Among numerous analytical techniques developed for lignins, solution-state multidimensional NMR provides unparalleled details of the polymers’ structural features to be elucidated. With an ability to diagnostically identify and approximate the diverse array of the structural elements in lignin polymers, the NMR techniques are becoming essential in numerous lignin research settings including those aiming to investigate the biosynthesis, bioengineering and biodegradation lignins, as well as the chemistry of lignins in various chemical and biochemical contexts in the light of the biorefinery concept. This chapter review will consider some basic and practical aspects of such NMR implementations in current lignin research. Specifically, a handful of key 2D and 3D NMR experiments for characterizing lignins and basic strategies for preparing suitable cell wall lignin samples to apply these NMR techniques are discussed. Keywords: biomass, HMBC, HSQC, plant cell walls, quantitative HSQC, TOCSY * Corresponding Author Email: ytobimatsu@rish.kyoto-u.ac.jp. No part of this digital document may be reproduced, stored in a retrieval system or transmitted commercially in any form or by any means. The publisher has taken reasonable care in the preparation of this digital document, but makes no expressed or implied warranty of any kind and assumes no responsibility for any errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of information contained herein. This digital document is sold with the clear understanding that the publisher is not engaged in rendering legal, medical or any other professional services.