Benzoxanthene Lignans: Biomimetic synthesis and Pharmacological Potential

Lignans are plant secondary metabolites normally biosynthesized from two phenylpropanoid units by oxidative coupling mediated by the action of laccases.1 Benzoxanthenes (BXL) are rare fluorescent phenolic compounds belonging to this class of secondary metabolites. Their discovery from natural sources is limited to a dozen molecules. In the last 20 years, some benzoxanthene lignans have been synthesized in laboratory with a biomimetic process starting from natural and natural-derived phenylpropanoids. In this synthesis Mn3+ revealed a certain regio-selectivity in affording the fluorescent structure over other possible lignans.2 From the development of this reaction, many BXL differently modified have been obtained and evaluated form several biological properties.3 Considering the promising antiproliferative activity and DNA-binding capability showed by BXL, our efforts have been dedicated to develop a more sustainable approach for their synthesis involving biocatalysts such as laccases, while avoiding the use of toxic organic solvents. Different laccases were screened in these experiments, and mediators were included in a set of reaction for improve reaction yield. The results will be reported herein.