PODOPHYLLOTOXIN: SOURCES, EXTRACTION, AND PREPARATION OF CYTOTOXIC ANALOG COMPOUNDS

Introduction Podophyllotoxin is the most abundant lignan isolated from Podophyllin, the resin obtained from species of the genera Podophyllum (Berberidaceae) (Ayres, 1990 and refs. cited therein). Lignans are a family of natural products that originated as secondary metabolites through the shikimic acid pathway. They are formed by the union of two phenylpropane units and constitute a complex family of skeletons and characteristic functionalizations, which can be subdivided into four groups: lignans, neolignans, oxyneolignans, and trimers, higher analogs, and mixed lignanoids (Moss, 2000). Among the lignans group, cyclolignans present a carbocycle between both phenylpropane units, created by two single carbon–carbon bonds through the side chains, one of them between the β−β' positions. The aryltetralin structure of podophyllotoxin belongs to cyclolignans.