6,7-Dimethyl-8-ribityllumazine

6,7-Dimethyl-8-ribityllumazine (DMRL) is a molecule that plays a crucial role in the biosynthesis of riboflavin, also known as vitamin B2. It is an intermediate compound in the biosynthetic pathway of riboflavin in microorganisms, plants, and yeast.

Structure and Properties[edit | edit source]

6,7-Dimethyl-8-ribityllumazine is a heterocyclic compound with a tricyclic structure. It consists of a lumazine ring, which is a derivative of pteridine, substituted at position 8 by a ribityl group and at positions 6 and 7 by methyl groups.

Biosynthesis[edit | edit source]

The biosynthesis of 6,7-dimethyl-8-ribityllumazine involves several steps. The first step is the condensation of 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione (also known as 5-amino-6-ribitylaminouracil) with 3,4-dihydroxy-2-butanone 4-phosphate, catalyzed by the enzyme lumazine synthase. This reaction results in the formation of 6,7-dimethyl-8-ribityllumazine.

The next step is the conversion of 6,7-dimethyl-8-ribityllumazine to riboflavin by the enzyme riboflavin synthase. This reaction involves the removal of a molecule of water and the formation of a fourth ring, resulting in the characteristic structure of riboflavin.

Role in Disease[edit | edit source]

Defects in the biosynthesis of riboflavin, including the formation of 6,7-dimethyl-8-ribityllumazine, can lead to riboflavin deficiency, which can cause various health problems, including anemia, skin disorders, and neurological disorders.