Extraction and purification of podophyllotoxin from eastern red cedar (Juniperus virginiana L.) in Oklahoma

Abstract

Podophyllotoxin (ptox) is a pharmaceutical derived from plants used in a broad spectrum of medicinal treatments ranging from inflammatory diseases to cancer. Originally sourced from the rhizomes of the now endangered Indian mayapple (Podophyllum emodi Wall.), ptox can also be found in the foliage of eastern red cedar (ERC). Ptox has been extracted from the foliage of ERC for analytical purposes (Renouard et al., 2011) but no effort has been documented to extract at commercial scale, nor have any attempts to purify ptox from the ERC foliage extract been attempted. This work was intended to develop scalable processes and procedures to extract ptox from dried ERC foliage and then concentrate and partially purify it. Extraction and purification of ptox from ERC foliage required the determination of optimum extraction variables, combined with macroporous resin enrichment of ptox from the extract. The greatest ptox extraction yield was obtained using the combination of a 60 degrees C extraction temperature, 20% ethanol solvent, 1 h extraction duration and a 20:1 solvent:feedstock ratio. The ERC foliage extract was enriched from 0.5 to 0.6% in the field dried ERC foliage to 14% in a 70% methanol eluate from a PAD900 macroporous resin column with 70% recovery of ptox. Using the 70% methanol eluate, we determined that solvent precipitation with sodium carbonate, followed by extraction in ethyl acetate, and re-crystallization in a methanol:chloroform solvent can purify ptox from ERC foliage extract to 89% (dry weight), but with only 10% recovery of ptox throughout the process.