Synthesis of Perbenzoylated Carbohydrates in Preparation for Anthocyanin Pigment Characterization Brandon Lew March 15, 2006
Jan 14, 2016
Synthesis of Perbenzoylated Carbohydrates in Preparation for
Anthocyanin Pigment Characterization
Brandon Lew
March 15, 2006
Introduction
• Purpose:
To develop a technique for carbohydrate characterization through NMR so that anthocyanin carbohydrate tails may be characterized.
Anthocyanins
http://www.mariquita.com/images/photogallery/strawberries.jpg http://www.personal.psu.edu/staff/m/h/mhl100/images/blueberries.jpg
Carbohydrate Tails
O+
OH
H
OH
OH
R2
OH
R1
35
7
3' 4'
5'
Anthocyanidin Base
O
HOH
OH
OH
H
H
OH
OH
H
Anthocyanin Characterization
• NMR of anthocyanins
Seeram et al. 2002
• Separation of tails
Takeoka et al. 2005
• Combine to perform NMR on separated tails
Carbohydrates
ChairChain
C 4
C 3
C 2
C 1
O
C 5
HOH
OH
OH
H
H
OH
H
C 6
OH
H
OH
C 2
C 3
OHH
C 4 OHH
C 5
C 6
H
OHH
OHH
HOH
C 1
OHH
Can Twist,Resulting inBeta-Anomer
In Beta-Anomer,These are Flipped
Perbenzoylation
• Levene and Meyer (1927) Glucose
• D’Accorso et al. (1981) NMR data of many monosaccharides
R
O
R
O
Perbenzoylation (Protocol 1)
O
HOH
OH
OH
H
H
OH
H OH
H
O
H
H
H
H
OBz
HOBz
BzO
BzO
OBz
O
Cl
Pyridine
100 oC
β-glucose Perbenzoylated-β-glucose
Purification
• Thin-layer chromatography (TLC)
• Column chromatography
• High-pressure liquid chromatography (HPLC)
http://www.hamline.edu/depts/chemistry/facility/images/hplc.jpg
Nuclear Magnetic Resonance Spectroscopy (NMR)
1H/13CEM radiation
Excited State
Ground StateRadio wave Detector
Magnetic Field
Protocol 1 Results: 1H NMR of perbenzoylated β glucose
Protocol 1 Results: HPLC of perbenzoylated maltose
Protocol 1 Results: 13C NMR of perbenzoylated maltose
Perbenzoylation (Protocol 2)
O
HOH
OH
OH
H
H
OH
H OH
H
O
H
H
H
H
OBz
HOBz
BzO
BzO
OBz
O
Cl
Pyridine, CHCl3
0 oC
β-glucose Perbenzoylated-β-glucose
Protocol 2 Results: 1H NMR of perbenzoylated β glucose
Protocol 2 Results: HPLC of perbenzoylated β glucose
Procedure 2 Results: 1H NMR of perbenzoylated α glucose
Conclusion• Protocol 1 – contaminated
• Some disaccharides selectively benzoylated
O
HOH
OH
OH
H
H
OH
H OH
H
O
H
H
H
H
OBz
HOBz
BzO
BzO
OBz
O
Cl
Pyridine
100 oC
β-glucose Perbenzoylated-β-glucose
Conclusion• Protocol 2 – purer, quicker
• Perbenzoylation works for characterization
O
HOH
OH
OH
H
H
OH
H OH
H
O
H
H
H
H
OBz
HOBz
BzO
BzO
OBz
O
Cl
Pyridine, CHCl3
0 oC
β-glucose Perbenzoylated-β-glucose
Future Work
• Use perbenzoylation to characterize carbohydrate tails of anthocyanins
• Anthocyanins differ by their tails
• Important for developing anti-oxidant food additives
Acknowledgements
• Dr. Matachek
• Hamline University
• Ms. Fruen
• Ms. Richter, Bill Mitchell
• Team Research
Synthesis of Perbenzoylated Carbohydrates in Preparation for
Anthocyanin Pigment Characterization
Brandon Lew
March 15, 2006