soapbark

noun

soap·​bark ˈsōp-ˌbärk 

: a Chilean tree (Quillaja saponaria) of the rose family with glossy leaves and terminal white flowers

also : its saponin-rich bark used in cleaning and in emulsifying oils

Example Sentences

Recent Examples on the Web

In fact, the AS01B adjuvant in the Shingrix vaccine (the recombinant herpes zoster vaccine to prevent Shingles) includes QS-21, which is also extracted from the Chilean soapbark tree. —Bruce Y. Lee, Forbes, 15 July 2022

Matrix-M relies on quillaja extract from soapbark trees. —Sarah Jane Tribble, baltimoresun.com, 19 July 2021

Matrix-M is made from the bark of the soapbark tree, which is abundant in Chile. —Justin Meneguzzi, National Geographic, 13 Nov. 2020

Though the company has deemed the soapbark adjuvant as safe, it has not yet been evaluated as part of a final product submitted to the U.S. Food and Drug Administration. —Justin Meneguzzi, National Geographic, 13 Nov. 2020

The rare Chilean soapbark tree produces compounds that can help boost the body’s reaction to vaccines. —Brendan Borrell, The Atlantic, 21 Oct. 2020

This was it: a Chilean soapbark, one of a handful planted on the Berkeley campus starting in the late 1800s. —Brendan Borrell, The Atlantic, 21 Oct. 2020

This was Ricardo San Martin, a scientist who had helped develop the Chilean soapbark industry. —Brendan Borrell, The Atlantic, 21 Oct. 2020

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Word History

First Known Use

1861, in the meaning defined above

Medical Definition

soapbark

noun

soap·​bark ˈsōp-ˌbärk 

1

: a Chilean tree of the genus Quillaja (Q. saponaria) with shiny leaves and white flowers

2

: the saponin-rich bark of the soapbark tree used in cleaning and in emulsifying oil

called also quillaja