The Metabolic Pathway of Shikimic Acid Aromatic Amino Acids Phenolic Compounds

1. The Metabolic Pathway ofShikimic Acid Aromatic Amino AcidsPhenolic Compounds Jan Michael O. Santos Philippine Normal University College of Science Department of Physical Sciences

2. Outline of Discussion 1. Shikimic Acid Pathway • Origin of Shikimic Acid • Starting Material • Enzymes • Pathway- Mechanism • Product

3. 2. Aromatic Amino Acids • What are the Aromatic Amino Acids • Starting Material • Enzymes • Pathway- Mechanism • Products

4. 3. Phenolic Compounds • What are Phenolic Compounds • Starting Material • Enzymes • Pathway- Mechanism • Products

5. DEFINITION OF TERMS • Shikimic acid or shikimate: is an important biochemical metabolite in plants and microorganisms. • Aromatic compound: is a hydrocarbon with alternating double bonds and single bonds between carbon atoms • Amino acids: are molecules containing an amine group, a carboxylic acid group and a side chain (specific)

6. 4. Phenolic Compounds: are a large and diverse group of molecules, which includes many families of aromatic secondary metabolite in plants. 5. Enzymes: are group of molecules that serve as a catalyst with a high degree of specificity for a certain substrate or class of substrates. It can only act on one substrate or on a family of structurally similar substrates.

7. MAJOR ENZYMES • Synthase: Joints two molecules together w/o hydrolyzing a pyrophosphate bond. • Dehydratase: Removes water to create a double bond • Dehydrogenase: Removes hydrogen atom from its substrate • Kinase: Transfer a phosphate group from a high-energy phosphate compound such as ATP to its substrate.

8. SHIKIMIC ACID

9. Where this came from? Shikimi Illiciumanisatum

10. Shikimic acid is a precursor for: • Aromatic amino acids phenylalanine and tyrosine • Indole, and indole derivatives and a.a.a tryptophan • Alkaloids • Phenylpropanoids, flavonoids, tannins, and lignins.

11. FORMATION OF SHIKIMIC ACID Starting materials 1st: Pyruvate to Phospoenolpyruvate

12. FORMATION OF SHIKIMIC ACID 2nd : Erthryrose-4-phosphate

13. FORMATION OF SHIKIMIC ACID Analyze this reaction, what are the other materials involve?

14. FORMATION OF SHIKIMIC ACID 3-deoxy-D-arabinoheptulosonate 7-phosphate (DAHP) synthase is the first enzyme in a series of metabolic reactions known as the shikimate pathway. Since it is the first enzyme in the shikimate pathway, it controls the amount of carbon entering the pathway.

15. FORMATION OF SHIKIMIC ACID

16. FORMATION OF SHIKIMIC ACID phosphoenolpyruvate B: H+ erythrose-4-phosphate H+ H+ NADPH shikimic acid

17. FORMATION OF SHIKIMIC ACID 3-dehydroquinate synthaseis the second enzyme of the shikimate pathway. It catalyzes the elimination of phosphate from DAHP to generate 3-dehydroquinate (DHQ).

18. FORMATION OF SHIKIMIC ACID

20. FORMATION OF SHIKIMIC ACID 3-Dehydroquinate Dehydratase (DHQD) catalyzes the third step of the shikimate pathway, dehydration of 3-dehydroquinate to 3-dehydroshikimate.

21. FORMATION OF SHIKIMIC ACID

23. FORMATION OF SHIKIMIC ACID Shikimate-5-Dehydrogenase (SDH) The fourth step of the shikimate pathway is the reduction of DHS to shikimate. the reaction is catalyzed by an NADP-dependent shikimatedehydrogenase (SHD)

24. FORMATION OF SHIKIMIC ACID

25. FORMATION OF SHIKIMIC ACID

26. FORMATION OF SHIKIMIC ACID ShikimateKinase (SK)- In the fifth step of the shikimate pathway, shikimatekinase catalyzes the specific phosphorylation of the 3-hydroxyl group of D-shikimate to yield shikimate 3-phosphate using ATP as a co-subtrate

27. FORMATION OF SHIKIMIC ACID

29. FORMATION OF SHIKIMIC ACID 5-Enolpyruvylshikimate 3-Phosphate Synthase (EPSPS) is the sixth enzyme of the shikimate pathway. It catalyzes the reversible formation of 5-enolpyruvyl-shikimate-3- phosphate (EPSP) from shikimate 3-phosphate and PEP.

30. FORMATION OF SHIKIMIC ACID

32. FORMATION OF SHIKIMIC ACID ChorismateSynthase (CS) The seventh and final step in the main trunk of the shikimate pathway is the trans-1,4 elimination of phosphate from EPSP to yield chorismate

33. FORMATION OF SHIKIMIC ACID In this reaction, the second of the three double bonds of the benzene ring is introduced. The reaction is catalyzed by chorismatesynthase and requires reduced flavin for activity even though the overall reaction is redox neutral.

34. FORMATION OF SHIKIMIC ACID

36. SHIKIMIC ACID TO AROMATIC ACID The seven-step shikimate pathway links the metabolism of carbohydrates to the biosynthesis of aromatic amino acids and many aromatic secondary metabolites, including tetrahydrofolate and ubiquinone.

38. Aromatic Amino Acids Y F W

39. Aromatic Amino Acids 1. What are aromatic amino acids? Aromatic Amino Acids are amino acids that include an aromatic ring. Example includes: Phenylalanine, Tryptophan, Histidine, Tyrosine (but only F, W, Y can be synthesized by Shikimate pathway)

40. The Aromatic Family • In plants and microorganism: Phe, Tyr, and Trp • Precursors are: • PEP • ERYTHROSE-4-PHOSPHATE • CHORISMATE

41. The Starting Material CHORISMATE

42. Enzymes Isomerase is an enzyme that catalyzes the structural rearrangement of isomers. Mutase: catalyzes the shifting of a functional group from one position to another within the same molecule. Transferase: catalyzes the transfer of a functional group (methyl or phosphate)from one molecule to another

43. The Pathway

44. The Mechanisms From Chorismate to Prephenate Chorismatemutase catalyzes the Claisen rearrangement of chorismate ion to prephenate ion

45. The Mechanisms What is Claisen Rearrangement? • Claisen Rearrangement is a powerful carbon-carbon bond-forming chemical reaction discovered by Rainer Ludwig Claisen.   

46. In NMR spectrum (chair conformation)

47. Chair and Boat Conformation

48. OVER-ALL STRUCTURE CHORISMATE PREPHENATE

49. Phenylalanine Biosynthesis

50. Prephenatedehyrdatase to Phenylpyruvate