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Avenanthramides in Oat Mitchell L. Wise USDA, ARS Cereal Crops Research Madison, WI. OUTLINE OF PRESENTATION. Phenylpropanoid/avenanthramide biosynthesis Health benefits of avenanthramides Application of suspension cultures to investigate avenanthramide biosynthesis.
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Avenanthramides in Oat Mitchell L. Wise USDA, ARS Cereal Crops Research Madison, WI
OUTLINE OF PRESENTATION • Phenylpropanoid/avenanthramide biosynthesis • Health benefits of avenanthramides • Application of suspension cultures to investigate avenanthramide biosynthesis
General Phenylpropaniod Pathway Glycolysis pentose phosphate + phosphoenolpyruvate erythrose-4-phosphate Protein Tryptophan/protein Shikimate pathway Tyr + Phe Anthranilate PAL Phenylpropanoids phytoalexins phenolic acids lignins flavonoids
Reaction of Phenylpropanoid and 5-Hydroxyanthranilic Acid Catalyzed by HHT Form R phenylpropanoid A (Bp) H p-Coumaric B (Bf) OH caffeic C (Bc) OCH3 ferulate
Grain Avenanthramide Content Shows Strong Genotype X Environment Interaction Emmons & Peterson, Crop Sci 41:1676 (2001)
Grain Avenanthramide Content Shows Strong Genotype X Environment Interaction Emmons & Peterson, Crop Sci 41:1676 (2001)
Effect of Avenanthramide C on VSMC Proliferation [3H] thymidne incorporation (% of control) Nie, Wise, Peterson, Meydani, Atherosclerosis, 186, 260-266 (2006).
Avn C inhibition of Restinoblastosis protein (pp-Rb) polyphosphorylation in VSMC Nie, Wise, Peterson, Meydani, Free Rad. Biol. Med, in press
Effect of Dietary Avenanthramide C on Exercise Stressed Rats Reduction of oxidized glutathione levels and higher ratio of reduced to oxidized form of glutathione. O’Moore and Ji, (2006) unpublished results.
Summary of Health Effects • Reduces vascular smooth muscle cell proliferation • Increased NO production • Inhibition of ppRb, arrest G1-S1 cell cycle progression • Elevation in anti-oxidant enzyme system in rats
HPLC Trace of Media Extract Subsequent to Chitin Elicitation
Avenanthramide A in Culture Media After Elicitation with Chitin
Avenanthramide A in Tissue Extracts Subsequent to Chitin Elicitation
Northern Analysis of Suspension Cells for Barley PR-1 and HHT Subsequent to Elicitation 18S RNA bPR-1 HHT
Conclusions/Future Directions • Avenanthramides are a “value added” phytonutrient unique to oat • Avn content in the grain is highly variable • Basis for variability is unknown • Suspension cultures offer a model to study avenanthramide biosynthesis at the molecular level • SSH cDNA library prepared • What is the involvement of the various isozymes (HHT, 4-CL, PAL)?
Jean Mayer Human Nutrition Research Center MOHSEN MEYDANI LIN NIE Univ Wisconsin, Dept Kinesthesiology LI LI JI KATHLEEN O’MOORE Cereal Crops Research RACHEL ANGEL LAURI HERRIN NICKOLAS PARTRIDGE RON SKADSEN JOHN HERBST ACKNOWLEDGEMENTS