Lignins and Lignans – Recent Developments and Trends Regarding their Pharmaceutical Properties

Lignins and lignans as natural polyphenols exhibit a rather broad variety of common physico-chemical features that can be of interest with respect to their use in the pharmaceutical sector. While polyphenol types have antioxidant, antiinflammatory, antibacterial and eventually antiviral activities in common, structural features beyond the polyphenol aspect differ enormously: isolated lignins are oligomers and/or polymers of monolignol C9-building blocks, while lignans are based on dimers thereof. The structural differences caused lignin to be exploited in the pharmaceutical sector mainly as material for the generation of matrices and carrier for drug delivery, while lignans are tested for the suitability as APIs. The chapter gives an overview of this situation, including the biological backgrounds of the two interesting natural polyphenols, isolation and methods for their characterisation.