Botanists unlock the Chilean medical marvel that Charles Darwin missed

Vaccine properties of the soapbark tree to be cultivated in days rather than years by new process

- James Tapper

When Charles Darwin first encountered the soapbark tree on a journey through Chile on his way to the Andes, he was perplexed as to why people found it so fascinating. “[Their] extreme pleasure, I suspect, is chiefly owing to the prospect of a good fire,” he wrote in his diary on 6 April 1835.

To Darwin's modern counterparts, making firewood from soapbark would be more extravagant than using gold leaf for toilet paper. The tree, Quillaja saponaria, has become a vital part of the vaccine supply chain because its bark is refined into a substance called QS-21, worth as much as US$400,000 a gram.

Yet deforestation is forcing researchers to look for new ways to secure vaccine ingredients, and now researchers in Norfolk have found a way to make QS-21 in a matter of days rather than decades.