Secondary Products - II

1. Secondary Products - II Phenolics

2. Phenolics

3. Synthesis of Phenolics • Phenolics are synthesized by a number of different pathways • Two most important: • Shikimic acidpathway - more important in plants • Malonic acid pathway - more important in fungi

4. Shikimic Acid Pathway • Converts intermediates from glycolysis (phosphoenol-pyruvate) and the PPP (erythrose-4-PO4) into the aromatic amino acids: phenylalanine, tryptophan, and tyrosine

6. See Shikimic Acid Pathway

8. See Pathway for Phenolic Secondary Products

9. Simple Phenolics • Allelopathic compounds • Defense cmpds against insect herbivores and fungi • Certain phenolics (furanocoumarins) are phototoxic - not toxic till activated by sunlight (near UV-A) • Activated furanocoumarins can insert into DNA and bind to pyrimidine bases - blocks transcription and leads to cell death • Abundant in Apiaceae • Urushiol in poison ivy

10. Urushiol Poison ivy urushiol Poison oak urushiol

11. Coumarins • Large group – 1300 coumarins have been identified • Basic coumarin is a 2 ring structure, phenol and pyrone • Many anticoagulants including Warfarin

12. Lignin a complex phenolic Lignin monomers • Polymer of three phenolic alochols • Different species have different ratios of these monomers • Lignin in beech has 100:70:7 of coniferyl: sinapyl: para-coumaryl

14. Flavinoids • One of the largest classes of phenolics • Carbon skeleton has 15 carbons with two benzene rings connected by a 3-C bridge -C3-

15. Flavinoids • Flavinoids classified into different groups based on the degree of oxidation of the 3-C bridge • Anthocyanins • Flavones • Flavonols • Isoflavones • Majority of flavinoids exist as glycosides

16. Anthocyanins

17. Tannins • Tannin a general name for a large group of complex phenolic substances that are capable of tanning animal hides into leather by binding collagen

18. Tetrahydrocannabinol