This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Danishefsky spirotryprostatinB synthesis. en August created this image myself and release it into the public domain Transferred from org en transferred to Commons by User Ronhjones using de php CommonsHelper Original uploader was Talbotron at org en Released into the public domain by the author en Talbotron Original