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.
MenadioneDballs. Ballandstick model of the menadione molecule Derived from File benzoquinoneDballs File HydroquinoneDballs and File LvalineDballs Jynto and Ben Mills Naphthoquinones Vitamin Images by Jynto
Page 2023 Free-images.com. All images are Public Domain