Progress 10/01/01 to 09/30/05
Outputs
We developed a method of estimating relative ratios of A-type:B-type interflavan bonds by deconvolution of overlapping isotope patterns. MALDI-TOF MS was used to characterize the structural diversity of PA in HyRed cranberry [Vaccinium macrocarpon, Ait.]. Positive reflectron mode mass spectra showed HyRed cranberry and Ruby Red sorghum PA had unique isotopic clusters showing variation in the nature of interflavan bonds (A-type and B-type; Δ 2 amu). Deconvolution indicated that oligomers, in which one or more interflavan bonds are A-type, occur in a higher proportion than oligomers in which all interflavan bonds are B-type. These isotope patterns are unique to individual foods or beverages and are not an artifact of instrumentation. This deconvolution method was used to characterize the relative ratios of A-type to B-type interflavan bonds as influenced by LC (LH-20 and C-18) fractionation. MALDI-TOF MS indicates that the DP of PA oligomers in the LH-20 fractions
increased in relation to their order of elution. Fraction LH1 contained no PA oligomers, LH2 PA were of 2 to 5 DP, LH3 PA were of 3 to 6 DP, LH4 PA were of 3 to 9 DP, LH5 PA were of 5 to 10 DP, and LH6 PA were of 5 to 12 DP. MALDI-TOF MS also indicates the presence of PA oligomers that contain one gallocatechin unit (Δ 16 amu) at each DP. Deconvolution of isotopic clusters indicated that PA oligomers, in which one or more interflavan bonds are A-type, occur in a higher proportion than oligomers in which all interflavan bonds are B-type. Specifically, PA containing one A-type interflavan bond were the most abundant type in all fractions. All PA fractions were pigmented red, however, only fraction LH1 contained anthocyanins indicating the remaining fractions contained anthocyanin-PA oligomers. MALDI-TOF MS indicates that the DP of PA oligomers in the C18 sub-fractions were not influenced in relation to their retention time. Fraction LH3RP1 contained oligomers of 3 to 5 DP, LH3RP2
PA were of 3 to 5 DP, LH4RP1 PA were of 4 to 7 DP, LH4RP2 PA were of 4 to 7 DP, LH5RP1 and LH5RP2 produced poor spectra. MALDI-TOF MS also indicates the presence of PA oligomers that contain one gallocatechin unit (Δ 16 amu) at each DP. Deconvolution of isotopic clusters indicated that the relative ratio of A-type to B-type interflavan bonds are influenced by retention time on RPC18. Early eluting fractions (LH3RP1 and LH4RP1) contain PA oligmers in which one or more interflavan bonds are A-type, occur in a higher proportion than oligomers in which all interflavan bonds are B-type. Specifically, PA containing one A-type interflavan bond were most abundant in all fractions. Late eluting fractions (LH3RP2 and LH4RP2) did not contain any PA oligomers in which all interflavan bonds were B-type, instead all PA oligomers contained one or more A-type interflavan bonds.
Impacts
Information on the effects of cranberry PA on LDL oxidation may lead to the promotion of cranberries and cranberry juices as functional foods and increase consumer demand. Results from our research will assist the industry if we show that specific PA oligomers protect LDL from oxidation. The industry will be able to use this information to select genotypes or blend varieties to formulate juices that contain these types of PA. Result may help promote cranberries and cranberry juice as functional food.
Publications
- Reed, J.D., C.G. Krueger, M.M. Vestling. 2005. MALDI-TOF mass spectrometry of oligomeric food polyphenols. Phytochem. 66, 2248-2263.
- Krueger, C.G., M.M. Vestling and J.D. Reed. 2004. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of anthocyanin-polyflavan-3-ol oligomers in cranberry fruit [Vaccinium macrocarpon, Ait.] and spray dried cranberry juice. In: Red Wine Color: Revealing the Mysteries, Waterhouse, A. L. and Kennedy, J. A., editors. ACS Symposium Series 886. pp. 232-246.
- Reed, J. 2002. Cranberry flavonoids, atherosclerosis and cardiovascular disease. Critical Reviews in Food Science and Nutrition, 42(Suppl.): 3301-316.
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Progress 01/01/04 to 12/31/04
Outputs
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to characterize the structural diversity of a series of anthocyanin-polyflavan-3-ol oligomers in cranberry fruit and spray dried juice. MALDI-TOF mass spectra provide evidence for a series of compounds corresponding to anthocyanins; cyanidin-hexoses, cyanidin-pentose, peonidin-hexose and peonidin-pentose linked to polyflavan-3-ols through a CH3-CH bridge. Deionizing the isolated anthocyanin-polyflavan-3-ol oligomers with Dowex 50X8-400 cation exchange resin prior to mass spectral analysis allowed the detection of exclusively [M]+ ions because the singly charged oxonium cation does not require further cationization. MALDI-TOF mass spectra of the anthocyanin-polyflavan-3-ols that eluate from Sephadex LH-20 columns with water/ethanol (1:1) contained oligomers with a degree of polymerization (DP) of 1 to DP2. MALDI-TOF MS of the Sephadex-ethanol eluate contained a series
masses corresponding to DP1 to DP4 and the Sephadex-ethanol:methanol (1:1) eluate contained series masses corresponding to DP3 to DP5. The anthocyanin-polyflavan-3-ol oligomers also show structural variation in the nature of the interflavan bond (A-type and B-type). Anthocyanin-polyflavan-3-ol oligomers incorporating a CH3-CH bridge have been described in red wines as a condensation reaction between anthocyanins and flavan-3-ols via acetaldehyde. Our results provide evidence of these oligomeric anthocyanins in the cranberry fruit and unfermented spray dried cranberry juice.
Impacts
Our in vitro research suggests that cranberry flavonoids are potent antioxidants.
Publications
- Krueger, C.G., M.M. Vestling and J.D. Reed. 2004. Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry of Anthocyanin-Polyflavan-3-ol Oligomers in Cranberry Fruit [Vaccinium macrocarpon, Ait.] and Spray Dried Cranberry Juice. ACS Symposium Uncovering the Mysteries of Red Wine Pigments (in press).
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Progress 01/01/03 to 12/31/03
Outputs
We developed a method of estimating relative ratios of A-type:B-type interflavan bonds by deconvolution of overlapping isotope patterns. MALDI-TOF MS was used to characterize the structural diversity of PA in HyRed cranberry [Vaccinium macrocarpon, Ait.]. Positive reflectron mode mass spectra showed HyRed cranberry had unique isotopic clusters showing variation in the nature of interflavan bonds (A-type and B-type). Deconvolution indicated that oligomers, in which one or more interflavan bonds are A-type, occur in a higher proportion than oligomers in which all interflavan bonds are B-type. These isotope patterns are unique to individual foods or beverages and are not an artifact of instrumentation. This deconvolution method was used to characterize the relative ratios of A-type to B-type interflavan bonds as influenced by LC (LH-20 and C-18) fractionation. MALDI-TOF MS indicates that the DP of PA oligomers in the LH-20 fractions increased in relation to their order
of elution. Fraction LH1 contained no PA oligomers, LH2 PA were of 2 to 5 DP, LH3 PA were of 3 to 6 DP, LH4 PA were of 3 to 9 DP, LH5 PA were of 5 to 10 DP, and LH6 PA were of 5 to 12 DP. MALDI-TOF MS also indicates the presence of PA oligomers that contain one gallocatechin unit (16 amu) at each DP. Deconvolution of isotopic clusters indicated that PA oligomers, in which one or more interflavan bonds are A-type, occur in a higher proportion than oligomers in which all interflavan bonds are B-type. Specifically, PA containing one A-type interflavan bond were the most abundant type in all fractions. All PA fractions were pigmented red; however, only fraction LH1 contained anthocyanins indicating the remaining fractions contained anthocyanin-PA oligomers. MALDI-TOF MS indicates that the DP of PA oligomers in the C18 sub-fractions were not influenced in relation to their retention time. Fraction LH3RP1 contained oligomers of 3 to 5 DP, LH3RP2 PA were of 3 to 5 DP, LH4RP1 PA were of 4 to
7 DP, LH4RP2 PA were of 4 to 7 DP, LH5RP1 and LH5RP2 produced poor spectra. MALDI-TOF MS also indicates the presence of PA oligomers that contain one gallocatechin unit (16 amu) at each DP. Deconvolution of isotopic clusters indicated that the relative ratio of A-type to B-type interflavan bonds are influenced by retention time on RPC18. Early eluting fractions (LH3RP1 and LH4RP1) contain PA oligomers in which one or more interflavan bonds are A-type, occur in a higher proportion than oligomers in which all interflavan bonds are B-type. Specifically, PA containing one A-type interflavan bond were most abundant in all fractions. Late eluting fractions (LH3RP2 and LH4RP2) did not contain any PA oligomers in which all interflavan bonds were B-type; instead, all PA oligomers contained one or more A-type interflavan bonds.
Impacts
Information on the effects of cranberry PA on LDL oxidation may lead to the promotion of cranberries and cranberry juices as functional foods and increase consumer demand. Results from our research will assist the industry if we show that specific PA oligomers protect LDL from oxidation. The industry will be able to use this information to select genotypes or blend varieties to formulate juices that contain these types of PA.
Publications
- Krueger, C.G.; M.M. Vestling and J.D. Reed. MALDI-TOF MS demonstrates that the structural diversity of polyflavans in foods and beverages is much greater than previously Appreciated. Abstract and Poster presentation at The 51st Annual Conference on Mass Spectrometry and Allied Topics, June 2-12, 2003 in Montreal, Quebec, Canada.
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Progress 01/01/02 to 12/31/02
Outputs
The earliest form of atherosclerosis is a fatty streak, formed when intimal macrophages have accumulated oxidized LDL in an unregulated manner. Oxidized LDL is recognized by scavenger receptors of macrophages and engulfed. Our research showed that cranberry proanthocyanidins specifically associate with LDL after addition to serum and remain associated with LDL throughout the isolation and preparation procedure. The cranberry proanthocyanidins increase the lag time of Cu+2 induced LDL oxidation. Therefore, cranberry proanthocyanidins are effective anti-oxidants when associated with LDL and if absorbed may protect against oxidation of LDL. Proanthocyandins with higher degree of polymerization (DP) may have greater affinity for LDL than oligomers of lower DP and provide more antioxidant protection. More research on the isolation and characterization of individual proanthocyanidins is required to elucidate the relationship between structure and LDL oxidation.
Impacts
Our in vitro research suggests that cranberry flavonoids are potent antioxidants.
Publications
- Porter, M. L., C. G. Krueger, D. A. Wiebe, D. G. Cunningham and J. D. Reed. 2001. Cranberry Proanthocyanidins Associate with Low-Density Lipoprotein and Inhibit In Vitro Cu2+-Induced Oxidation. J. Sci. Food Agric. 1306-1313.
- Reed, J. 2002. Cranberry flavonoids, atherosclerosis and cardiovascular disease. Critical Reviews in Food Science and Nutrition, 42(Suppl.): 3301-316.
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Progress 01/01/01 to 12/31/01
Outputs
Antioxidant activity of cranberry proanthocyanidins was determined by inhibition of Cu2+ induced low-density lipoprotein (LDL) oxidation. The proanthocyanidin (PA) composition was determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, a technique that allows rapid characterization of the molecular weight and structural diversity of complex oligomeric compounds. The PA from cranberries were chromatographically separated into two fractions. Fraction 1 contained trimers through heptamers, whereas fraction 2 contained pentamers through nonamers. In addition fraction 2 contained PA oligomers with more doubly linked, A-type interflavan bonds. Both PA fractions significantly increased the lag time of LDL oxidation, and the lag time for fraction 2 was significantly higher than for fraction 1. Results indicate that PAs specifically associate with LDL in modified serum and increase the lag time of Cu2+ induced oxidation. Differences between
fractions 1 and 2 in PA structure and effects on LDL oxidation suggest that the degree of polymerisation and the nature of the interflavan bond influence antioxidant properties.
Impacts
(N/A)
Publications
- Howell, A., J. D. Reed, R. Winterbottom, C. G. Krueger. 2002. Bacterial anti-adhesion activity of cranberry vs. other foods. FASEB J., Late-Breaking Abstracts
- Porter, M. L., C. G. Krueger, D. A. Wiebe, D. G. Cunningham, and J. D. Reed. 2001. Cranberry proanthocyanidins associate with low-density lipoprotein and inhibit in vitro Cu2+ -induced oxidation. J Sci Food Agric 81:1306-1313.
- Reed, J. D., M. L. Porter, C. G. Krueger, D. A. Wiebe, and D. G. Cunningham. 2001. Cranberry proanthocyanidins differ in the inhibition of cupric induced oxidation of human low density lipoprotein. FASEB J., Abstracts 15 (5, II): A737.
- Reed, J. D., C. G. Krueger, and M. L. Porter. 2001. Cranberry juice powder decreases low density lipoprotein cholesterol in hypercholesterolemic swine. FASEB J., Late-Breaking Abstracts 15(4, 5): 54.
- Krueger, C. G., M. L. Porter, D. A. Wiebe, D.G. Cummingham, and J. D. Reed. 2000. Potential of cranberry flavonoids in the prevention of copper-induced LDL oxidation. Polyphenols Communications 2000, Volume 2, Freising-Weihenstephan (Germany), September 11-15, 2000. Pp. 447-448.
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