Definition of menadione in English:

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Pronunciation: /ˌmenəˈdīˌōn/


A synthetic yellow compound related to menaquinone, used to treat hemorrhage. Also called vitamin K3 (see vitamin K).
  • Alternative name: 2-methyl-1,4-naphthoquinone; chemical formula: C11H8O2.
Example sentences
  • This medium is prepared twice each week and is complemented with 8% sheep blood, menadione, and gentamicin, making this medium selective for anaerobes.
  • The K vitamins exist naturally as K 1 in green vegetables and K 2 produced by intestinal bacteria and K 3 is synthetic menadione.
  • After absorption, menadione is thought to become alkylated into biologically active isoprenylated menaquinones.


1940s: from me(thyl) + na(phthalene) + the suffix -dione, used in names of compounds containing two carbonyl groups.

For editors and proofreaders

Syllabification: men·a·di·one

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