Plant Pigments: Chlorophylls, Carotenoids & Anthocyanins in Photosynthesis & Protection, Summaries of Forestry

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Plant Pigments

Chromatography

Gary Stacey Lab

Teacher workshop, March 8, 2014 University of Missouri Division of Plant Sciences

Chromatography (from Greek χρῶμα chroma "color" and γράφειν graphein "to write") = color separation Paper chromatography

• Pigments from plant tissues are separated based on those chemical properties (i.e., molecular size/solubility/polarity) pigments

 Carotenoids and associated

xanthophylls:

 - act as accessory pigments and trap sunlight energy for photosynthesis.  - act as photo-protective agents, protecting the plants from the effects of excess energy build up that causes the formation of toxins in plants  - anti-oxidants, precursor for vitamin A formation, good for vision maintenance Carotenoids

Carotenoids and xanthophylls

• tetra-terpenes
• are non-polar
• represent more 60 pigments  Carotenoids

 Anthocyanins

 - phenolic pigments  - are polar  - water soluble Anthocyanins

Chromatography (from Greek χρῶμα chroma "color" and γράφειν graphein "to write") = color separation Paper chromatography

• Pigments from plant tissues are separated based on those chemical properties (i.e., molecular size/solubility/polarity) pigments

Rf values of pigments Carotene - 0.98; orange Pheophytin - 0.81; olive green Chlorophyll a - 0.59; blue-green Chlorophyll b - 0.42; yellow-green Anthocyanins - between 0.32 and 0.62; red, pink, purple and blue colors Xanthophyll 1 - 0.28, yellow Xanthophyll 2 - 0.15, yellow www.bioquest.org/summer2008/projectfiles/leaf chromat ography .doc Chromatography Background

Chromatography Background  It is possible to measure the solubility of a pigment in a solvent by measuring how far the pigment travels vs. how far the solvent travels  This is called retention factor, or R f value  Rf values are characteristic of specific pigments and can be used to identify them  The higher the Rf value, the less polar the compound.  Thus, a compound not migrating from the origin would have an Rf of 0, a compound migrating with the solvent front would have an Rf of 1.0, and a compound migrating half as far as the solvent front would have an Rf of 0.5.

References http://warnell.forestry.uga.edu/service/library/index.php3?docID=144&docHistory[]=2& docHistory[]= http://eng.ege.edu.tr/~otles/ColorScience/anthocyanins.htm www.bioquest.org/summer2008/projectfiles/leafchromatography.doc http://facstaff.bloomu.edu/mpugh/Experiment2.pdf http://www.ucmp.berkeley.edu/glossary/gloss3/pigments.html Reiss, Carol 1994. Experiments in Plant Physiology. Englewood Cliffs, NJ: Prentice Hall. http://nationalnursingreview.com/2010/08/beta-carotene-benefits-health/ http://www.biotechlearn.org.nz/focus_stories/breeding_red_fleshed_apples/images/fruits _high_in_anthocyanins