Question

(This is BIOchemistry) While seeking some vitamin supplements, you happen across two brands that both advertise containing vitamin B6. Reading the labels, you see one contains pyridoxamine (PM) and the other contains pyridoxine (PN).

a.) Is there any difference in effectiveness between the two brands? In your answer, explain what metabolically-important compound is being made and what enzymes are needed.

b.) A third bottle contains a compound called pyritinol and advertises itself as being a study aid or "smart drug". How is it similar or different from the two compounds above, PM and PN? What was it originally used for? Propose a mechanism/pathway for pyritinol's effects.

(This problem relates to chapters 22, Biosynthesis of amino acids, nucleotides, and related molecules; and chapter 23, hormonal regulation and integration of mammalian metabolism, from the Lehninger Biochemistry textbook).

Answer 1

Ans a. The brand comprising of pyridoxamine would be more effective as compared to the one consisting of pyridoxine. The vitamin B6 plyas a vital role in prevention from hyperoxularia type I. It is caused by the deficiency of liver perioxisomal alanine:glycoxylate aminotransferase. Hence the enzyme involved in it is AGT alanine glycoxylate aminotransferase.

Ans b. Pyritinol is pretty much similar to pyridoxine with the only contrasting difference between the two being the two molecules joined together by a disulfide bridge. It functions as an antihangover pill and a brain booster. It is concerned with the repair of damaged cholinergic nerves, enhances level of acetylcholine. It also increases the utilization of glucose and cGMP as well as cAMP levels in the brain.