Thapsigargin--from Thapsia L. to mipsagargin

The sesquiterpene lactone thapsigargin is found in the plant Thapsia garganica L., and is one of the major constituents of the roots and fruits of this Mediterranean species. In 1978, the first pharmacological effects of thapsigargin were established and the full structure was elucidated in 1985. Shortly after, the overall mechanism of the Sarco-endoplasmic reticulum Ca²⁺-ATPase (SERCA) inhibition that leads to apoptosis was discovered. Thapsigargin has a potent antagonistic effect on the SERCA and is widely used to study Ca²⁺-signaling. The effect on SERCA has also been utilized in the treatment of solid tumors. A prodrug has been designed to target the blood vessels of cancer cells; the death of these blood vessels then leads to tumor necrosis. The first clinical trials of this drug were initiated in 2008, and the potent drug is expected to enter the market in the near future under the generic name Mipsagargin (G-202). This review will describe the discovery of the new drug, the on-going elucidation of the biosynthesis of thapsigargin in the plant and attempts to supply the global market with a novel potent anti-cancer drug.

Nero and the last stalk of Silphion: collecting extinct nature in early modern Europe

Many studies of early modern natural history focus upon observational, empirical techniques. Early moderns also contended with entities which could no longer be observed because they no longer existed. Although it is often assumed that extinction only emerged as a concept in the eighteenth century, the concept of natural loss appeared, often unproblematically, in areas outside natural philosophy. A survey of discussions of the extinct plant silphion across Europe in the sixteenth and seventeenth centuries shows that the possibility of natural loss was well aired. Paper technologies for collecting extinct nature ran parallel to investigations of newly found nature, and thus can place the latter in a new light. Although ideas of natural mutability often drew on ideas of historical or political change rather than philosophical concepts of natural constancy, techniques developed for extinct nature, such as the list of lost things, remained influential for the research agendas of naturalists.