Isolation and extraction of lucidin primeveroside from Rubia tinctorum L. and crystal structure elucidation.

Highlights: [•] We extract and identify four compounds from Rubia tinctorum L. [•] Anthraquinone compounds identified are lucidin primeveroside, ruberythric acid, alizarin and lucidin-ω-ethyl ether. [•] We provide first known crystal structure of lucidin primeveroside. [•] We provide the first ever known crystal structure of an anthraquinone glycoside. [•] We demonstrate flaws in previous analysis of madder phytochemicals. [Copyright &y& Elsevier]