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Webster 1913 Edition

Noun.

(Chem.)

An orange-red crystalline substance,

C15H10O5

, obtained from the buckthorn, rhubarb, etc., and regarded as a derivative of anthraquinone; – so called from a species of rhubarb (

Rheum emodei

Structure diagram of emodin

emodin ‎(countable and uncountable, plural emodins)

(organic chemistry) A purgative resin, 6-methyl-1,3,8-trihydroxyanthraquinone, obtained from some rhubarbs and other plants.