Advertisement

Reactions at the A-ring of Proanthocyanidins

  • G. Wayne McGraw

Abstract

The most common reactions at the A-ring of proanthocyanidins (condensed tannins) are examples of electrophilic aromatic substitution where an electrophile displaces a hydrogen (i.e., at C-6 and/or C-8 of procyanidins and profisetinidins). Other types of displacements include dehalogenation, procyanidin degradation, and oxidative free-radical coupling. The hydroxylation pattern of the A-ring controls both reactivity and orientation of substitution, partially by steric effects, but electronic factors have more influence. Examples of A-ring reactions include those of commercial interest (methylolation, condensation) and of diagnostic interest (halogenation, alkylation, hydrogen/deuterium exchange). C- and O-glycosylation are further types of A-ring reactions leading to natural products.

Keywords

Condensed Tannin Ellagic Acid Bark Extract Pyran Ring Pyridinium Bromide 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Roux, D.G.; Ferreira, D. The direct biomimetic synthesis, structure and absolute configuration of angular and condensed tannins. Fortschr. Chem. Org . Naturst. 41: 47 (1982).Google Scholar
  2. 2.
    McGraw, G. W.; Hemingway, R.W. Electrophilic aromatic substitution of catechin: Bromination and benzylation. J. Chem. Soc. Perkin Trans. 1:974 (1982).Google Scholar
  3. 3.
    Kiatgrajai, P.; Wellons, J.D.; L. Gollob, L.; White, J.D. Kinetics of polymerizaiton of (+)-catechin with formaldehyde. J. Org . Chem. 47: 2913 (1982).Google Scholar
  4. 4.
    Haslam, E. Biogenetically patterned synthesis of procyanidins. J. Chem. Soc. Chem. Commun.: 594 (1974).Google Scholar
  5. 5.
    Botha, J.J.; Viviers, P.M.; Ferreira, D.; Roux, D.G. Condensed tannins: Competing nudeophilic centres in biomimetic condensation reactions. Phytochemistry 21: 1289 (1982).CrossRefGoogle Scholar
  6. 6.
    McGraw, G.W.; Hemingway, R.W.; Ohara, S. Reactions of tannin model compounds with methylolphenols. In: Hemingway, R.W.; Conner, A.H.; Branham, S.J. (eds.) Adhesives from Renewable Resources. Symposium Series No. 385, Amercian Chemical Society, Washington, DC. pp. 185–202 (1989).CrossRefGoogle Scholar
  7. 7.
    Weinges, K.; Perner, J.; Marx, H.-D. Synthese des octamethyl-diacetyl-procyanidins B3, Chem. Ber. 103: 2344 (1970).CrossRefGoogle Scholar
  8. 8.
    Engel, D.W.; Hattingh, M.; Hundt, H.K.L.; Roux, D.G. X-ray structure, conformation, and absolute configuration of 8-bromotetra-O-methyl-(+)-catechin. J. Chem. Soc. Chem. Commun.: 695 (1978).Google Scholar
  9. 9.
    Kiehlmann, E.; Lehto, N.; Cherniwchan, D. Iodination and deuteration of catechin derivatives. Can. J. Chem. 66: 2431 (1988).CrossRefGoogle Scholar
  10. 10.
    Fronczek, F.R.; Gannuch, G.; Mattice, W.L.; Hemingway, R.W.; Chiari, G.; Tobiason, F.L.; Houglum, K.; Shannafelt, A. Preference for occupancy of axial positions by substitutents bonded to the heterocydic ring in penta-0-acetyl-(+)-catchin in the crystalline state. J. Chem. Soc. Perkin Trans. 2: 1383 (1985).Google Scholar
  11. 11.
    Hundt, H.K.L.; Roux, D.G. Condensed tannins: Determination of the point of linkage in `terminal’ (+)-catechin units and degradative bromination of 4-flavanylflavan-3,4-diols. J. Chem. Soc. Chem. Commun.: 696 (1978).Google Scholar
  12. Nonaka, G.; Morimoto, S.; Nishioka, I. Tannins and related compounds. Part 13. Isolation and structures of trimeric, tetrameric, and pentameric proanthocyanidins from cinnamon. J. Chem. Soc. Perkin Trans. 1:2139 (1983).Google Scholar
  13. 13.
    Young, D.A.; Cronje, A.; Bates, A.L.; Ferreira, D.; Roux, D.G. Synthesis of condensed tannins. Part 14. Biflavanoid profisetinidins as synthons. The acid-induced `phlobaphene’ reaction. J. Chem. Soc. Perkin Trans. 1: 2521 (1985).CrossRefGoogle Scholar
  14. 14.
    Herrick, F.W.; Bock, L.J. Adhesives from bark extracts. For. Prod. J. 8: 269 (1958).Google Scholar
  15. 15.
    Hillis, W.E.; Urbach, G. Reactions of polyphenols with formaldehyde. J. Appl. Chem. 9: 665 (1959).CrossRefGoogle Scholar
  16. 16.
    Roux, D.G.; Ferreira, D.; Hundt, H.K.L.; Malan, E. Structure, stereochemistry, and reactivity of natural condensed tannins as basis for their extended industrial applicaiton. In: Timell, T.E. (ed.) Proc. of the Eighth Cellulose Conf. Appl. Polym. Symp. No. 28. John Wiley and Sons, New York (1975).Google Scholar
  17. 17.
    Pizzi, A.; Scharfetter, H.O. The chemistry and development of tannin-based adhesives for exterior plywood. J. Appl. Polym. Sci. 22: 1745 (1978).CrossRefGoogle Scholar
  18. 18.
    Plomley, K.F. Tannin-formaldehyde adhesives for wood. CSIRO, Div. For. Prod. Technol. Paper No. 39 (1966).Google Scholar
  19. 19.
    Porter L.J. Viscosity and formaldehyde consumption of procyanidin solutions. In: Hemingway, R.W.; Conner, A.H.; Branham, S.J. (eds.) Adhesives from Renewable Resources. Symposium Series, No. 385, American Chemical Society, Washington, DC. pp. 172–184 (1989).CrossRefGoogle Scholar
  20. 20.
    Hemingway, R.W.; McGraw, G.W. Formaldehyde condensation products of model phenols for conifer bark tannins. J. Liq. Chromatog. 1: 163 (1978).CrossRefGoogle Scholar
  21. 21.
    Hillis, W.E.; Urbach, G. The reaction of (+)-catechin with formaldehyde. J. Appl. Chem. 9: 474 (1959).CrossRefGoogle Scholar
  22. 22.
    Ayla, C. Pines brutia tannin adhesives. J. Appl. Polym. Sci., Appl. Polym. Symp. 40: 69 (1984).Google Scholar
  23. 23.
    Pizzi, A. Tannin-based wood adhesives. In: Pizzi, A. (ed.) Wood Adhesives: Chemistry and Technology. Marcel Dekker, Inc., New York, pp. 177–246 (1983).Google Scholar
  24. 24.
    Rossouw, D. du T.; Pizzi, A.; McGillvray, G. The kinetics of condensation of phenolic polyflavonoid tannins with aldehydes. J. Polym. Sci. Polym. Chem. Ed. 18: 3323 (1980).CrossRefGoogle Scholar
  25. 25.
    Foo, L.Y.; Hemingway, R.W. Condensed tannins: reactions of model compounds with furfuryl alcohol and furfuraldehyde. J. Wood Chem. Technl. 5: 135 (1985).CrossRefGoogle Scholar
  26. 26.
    Pizzi, A.; Rossouw, D.du T.; Daling, G.M.E. The role of aldehydes other than HCHO in tannin-based wood adhesives. Holzforsch. Holzverwert 32: 101 (1980).Google Scholar
  27. 27.
    MacLean, H.; Gardner, J.A.F. Bark extracts in adhesives. Pulp Paper Mag. Can. 53: 111 (1952).Google Scholar
  28. 28.
    Scharfetter, H.; Pizzi, A.; Roussouw, D.du T. IUFRO Conference on Wood Gluing, Merida, Venezuela, Oct. (1977).Google Scholar
  29. 29.
    Herrick, F.W.; Conca, R.J. The use of bark extracts in coldsetting waterproof adhesives. For. Prod. J. 10: 361 (1960).Google Scholar
  30. 30.
    Hemingway, R.W.; McGraw, G.W.; Karchesy, J.J. Condensation of hydroxybenzyl alcohols with catechin: a model for methylolphenols in conifer-bark polyflavonoid adhesives. In: Phenolic Resins, Chemistry and Applications. Weyerhaeuser Science Symposium 2, Weyerhaeuser Co., Tacoma, Washington, pp. 33–67 (1981).Google Scholar
  31. 31.
    Botha, J.J.; Ferreira, D.; Roux, D.G. Synthesis of condensed tannins. Part 4. A direct biomimetic approach to [4,6]- and [4,8]-biflavanoids. J. Chem. Soc. Perkin Trans. 1: 1235 (1981).CrossRefGoogle Scholar
  32. 32.
    Botha, J.J.; Viviers, P.M.; Young, D.A.; duPreez, I.C.; Ferreira, D.; Roux, D.G.; Hull, W.E. Synthesis of condensed tannins. Part 5. The first angular [4,6;4,8]-triflavanoids and their natural counterparts. J. Chem. Soc. Perkin Trans. 1: 527 (1982).CrossRefGoogle Scholar
  33. 33.
    Viviers, P.M.; Botha, J.J.; Ferreira, D.; Roux, D.G.; Saayman, H.M. Synthesis of condensed tannins. Part 7. Angular [4,6;4,8]-prorobinetindin triflavanoids from black wattle (`mimosa’) bark extract. J. Chem. Soc. Perkin Trans. 1: 17 (1983).CrossRefGoogle Scholar
  34. 34.
    Porter, L.J.; Foo, L.Y. Leucocyanidin: Synthesis and properties of (2R,3S,4R)-(+)-3,4,5,7,3’,4’-hexahydroxyflavan. Phytochemistry 21: 2947 (1982).CrossRefGoogle Scholar
  35. 35.
    Stafford, H.A.; Lester, H.H. Flavan-3-ol biosynthesis: The conversion of (+)-dihydroquercetin and flavan-3,4-cis-diol (leucocyanidin) to (+)-catechin by reductases extracted from cell suspension cultures of Douglas-fir. Plant Physiol. 76: 184 (1984).PubMedCrossRefGoogle Scholar
  36. 36.
    Stafford, H.A.; Lester, H.H.; Porter, L.J. Chemical and enzymatic synthesis of monomeric procyanidins (Leucocyanidins or 3’,4’,5,7-tetrahydroxy-flavan-3,4-diols) from (2R,3R)-dihydroquercetin. Phytochemistry 24: 333 (1985).CrossRefGoogle Scholar
  37. 37.
    Kolodziej, H. The first 2,3-trans-3,4-cis-procyanidin. Phytochemistry 24: 2460 (1985).CrossRefGoogle Scholar
  38. 38.
    Delcour, J.A.; Serneels, E.J.; Ferreira, D.; Roux, D.G. Synthesis of condensed tannins. Part 13. The first 2,3-trans-3,4-cis-procyanidins: sequence of units in a `trimer’ of mixed stereochemistry. J. Chem. Soc. Perkin Trans. 1: 669 (1985).CrossRefGoogle Scholar
  39. 39.
    Betts, M.J.; Brown, B.R.; Brown, P.E.; Pike, W.T. Degradation of condensed tannins: structure of the tannin from common heather. J. Chem. Soc. Chem. Commun.: 110 (1967).Google Scholar
  40. 40.
    Sears, K.D.; Casebier, R.L. Cleavage of proanthocyanidins with thioglycollic acid. J. Chem. Soc. Chem. Commun.: 1437 (1968).Google Scholar
  41. 41.
    Betts, M.J.; Brown, B.R.; Shaw, M.R. Reaction of flavanoids with mercaptoacetic acid. J. Chem. Soc. (C):1178 (1969).Google Scholar
  42. 42.
    Sears, K.D.; Casebier, R.L. The reaction of thioglycollic acid with polyflavanoid bark fractions of Tsuga heterophylla. Phytochemistry 9: 1589 (1970).CrossRefGoogle Scholar
  43. 43.
    Thompson, R.S.; Jacques, D.; Haslam, E.; Tanner, R.J.N. Plant proanthocyanidins. Part 1. Introduction; the isolation, structure, and distribution in nature of plant procyanidins. J. Chem. Soc. Perkin Trans. I: 1209 (1982).Google Scholar
  44. 44.
    Hemingway, R.W.; Foo, L.Y.; Porter, L.J. Linkage isomerism in trimeric and polymeric 2,3-cis-procyanidins. J. Chem. Soc. Perkin Trans. 1: 1209 (1982).CrossRefGoogle Scholar
  45. 45.
    Foo, L.Y.; Porter, L.J. Synthesis and conformation of procyanidin diastereoisomers. J. Chem. Soc. Perkin Trans. 1: 1535 (1983).CrossRefGoogle Scholar
  46. 46.
    Foo, L.Y. Facile self-condensation of melacacidin: a demonstration of the reactivity of the pyrogallol A-ring. J. Chem. Soc. Chem. Commun.: 1273 (1985).Google Scholar
  47. 47.
    Foo, L.Y. A novel pyrogallol A-ring proanthocyanidin dimer from Acacia melanoxylon. J. Chem. Soc. Chem. Commun.: 236 (1986).Google Scholar
  48. 48.
    Malan, E.; Roux, D.G. Flavonoids and tannins of Acacia species. Phytochemistry 14: 1835 (1975).CrossRefGoogle Scholar
  49. 49.
    Hemingway, R.W.; Foo, L.Y. Condensed tannins: quinone methide intermediates in procyanidin synthesis. J. Chem. Soc. Chem. Commun.: 1035 (1983).Google Scholar
  50. 50.
    Foo, L.Y.; Hemingway, R.W. Condensed tannins: synthesis of the first `branched’ procyanidin trimer. J. Chem. Soc. Chem. Commun.: 85 (1984).Google Scholar
  51. 51.
    Sears, K.D.; Casebier, R.L.; Hergert, H.L.; Stout, G.H.; McCandlish, L.E. The structure of catechinic acid. A base rearrangement product of catechin. J. Org . Chem. 39: 3244 (1975).Google Scholar
  52. 52.
    Laks, P.E.; Hemingway, R.W.; Conner, A.H. Condensed tannins. Base-catalyzed reactions of polymeric procyanidins with phloroglucinol: intramolecular rearrangements. J. Chem. Soc. Perkin Trans. 1: 1875 (1987).CrossRefGoogle Scholar
  53. 53.
    Laks, P.E.; Hemingway, R.W. Condensed tannins. Structure of the `phenolic acids’. Holzforschung 41: 287 (1987).CrossRefGoogle Scholar
  54. 54.
    Steenkamp, J.A.; Steynberg, J.P.; Brandt, E.V.; Ferreira, D.; Roux, D.G. Phlobatannins, a novel class of ring-isomerized condensed tannins. J. Chem. Soc. Chem. Commun.: 1678 (1985).Google Scholar
  55. 55.
    Steynberg, J.P.; Young, D.A.; Burger, J.F.W.; Ferreira, D.; Roux, D.G. Phlobatannins via facile ring isomerizations of profisetinidin and prorobinetinidin condensed tannin units. J. Chem. Soc. Chem. Commun.: 1013 (1986).Google Scholar
  56. 56.
    Furlong, J.J.P.; Nudleman, N.S. Base-catalyzed aromatic hydrogen exchange in phenols. Acta Sud Americana de Quimica 3: 129 (1983).Google Scholar
  57. 57.
    Weinges, K.; Ebert, W.; Huthwelker, D.; Mattauch, H.; Perner, J. Konstitution und Bildungsmechanismus des Dehydro-dicatechins. Liebigs Ann. Chem. 726: 124 (1969).Google Scholar
  58. 58.
    Hundt, H.K.L.; Roux, D.G. Synthesis of condensed tannins. Part 3. Chemical shifts for determining the 6- and 8-bonding positions of `terminal’ (+)-catechin units. J. Chem. Soc. Perkin Trans. 1: 1227 (1981).CrossRefGoogle Scholar
  59. 59.
    Kiehlmann, E.; van der Merwe, P.J.; Hundt, H.K.L. Synthesis of 6-bromo-, 8-bromo-, and 6,8-dibromocatechin. Org . Prep. Proc. Int. 15: 341 (1983).Google Scholar
  60. 60.
    Locksley, H.D. The chemistry of biflavonoid compounds. Fortschr. Chem. Org . Naturstoffe 30: 208 (1973).Google Scholar
  61. 61.
    Hathway, D.E. The condensed tannins. In: Hillis, W.E. (ed.) Wood Extractives. Academic Press, New York (1962).Google Scholar
  62. 62.
    Young, D.A.; Young, E.; Roux, D.G.; Brandt, E.V.; Ferreira, D. Synthesis of condensed tannins. Part 19. Phenol oxidative coupling of (+)-catechin and (+)-mesquitol. Conformation of bis-(+)-catechins. J. Chem. Soc. Perkin Trans. I:2345 (1987).Google Scholar
  63. 63.
    Hathway, D.E.; Seakins, J.W.T. Autoxidation of catechin. Nature 176: 218 (1955).CrossRefGoogle Scholar
  64. 64.
    Brown, B.R.; Whiteoak, R.J. Polymerisation of flavans. Part VII. Oxidative polymerisation of catechin. J. Chem. Soc.: 6084 (1964).Google Scholar
  65. 65.
    Geismann, T.A.; Crout, D.H.G. Organic Chemistry of Secondary Plant Metabolism. Freeman, Cooper and Co., San Francisco. (1969).Google Scholar
  66. 66.
    Hathway, D.E. Autoxidation of polyphenols. Part IV. Oxidative degradation of the catechinautoxidation polymer. J. Chem. Soc.: 520 (1958).Google Scholar
  67. 67.
    Jacobs, E.; Ferreira, D.; Roux, D.G. Atropisomerism in a new class of condensed tannins based on biphenyl and o-terphenyl. Tetrahedron Letters 24: 4627 (1983).CrossRefGoogle Scholar
  68. 68.
    Tonaka, T.; Nonaka, G.; Nishioka, I. 7-O-Galloyl-(+)-catechin and 3-O-galloylprocyanidin B-3 from Sanguisorba officinalis. Phytochemistry 22: 2575 (1983).CrossRefGoogle Scholar
  69. 69.
    Coxon, D.T.; Holmes, A.; 011is, W.D.; Vora, V.C.; Grant, M.S.; Tee, J.L. Flavanol digallates in green tea leaf. Tetrahedron 28: 2819 (1972).CrossRefGoogle Scholar
  70. 70.
    Nonaka, G.; Nishioka, I. Tannins and related compounds. VII. Phenylpropanoid-substituted epicatechins, cinchonains from Cinchona siccirubra. Chem. Pharm. Bull. 30: 4268 (1982).CrossRefGoogle Scholar
  71. 71.
    Nonaka, G.; Kawahara, O.; Nishioka, L Tannins and related compounds. VIII. A new type of proanthocyanidin, cinchonains lla and 11b from Cinchona succirubra. Chem. Pharm. Bull. 30: 4277 (1982).CrossRefGoogle Scholar
  72. 72.
    Hemingway, R.W. Biflavonoids and proanthocyanidins. In:Rowe, J.W. (ed.) Natural Products Extraneous to the Lignocellulosic Cell Wall of Wood Plants. Springer Verlag, New York (in press).Google Scholar
  73. 73.
    Miyamura, M.; Nohara, T.; Tomimatsu, T.; Nishioka, I. Seven aromatic compounds from the bark of Cinnamomum cassia. Phytochemistry 22: 215 (1983).CrossRefGoogle Scholar
  74. 74.
    Oberholzer, M.E.; Rall, G.J.H.; Roux, D.G. (2R,3S,4S)-3,4,7,3’,4’-Pentamethoxy-2,3-trans3,4-cis-flavan, a novel flavan from Neorautanenia amboensis. Phytochemistry 19: 2503 (1980).CrossRefGoogle Scholar
  75. 75.
    duPreez, I.C.; Roux, D.G. Novel flavan-3,4-diols from Acacia culturiformis. J. Chem. Soc. (C): 1800 (1970).Google Scholar
  76. 76.
    Nonaka, G.; Ezaki, E.; Hayashi, K.; Nishioka, I. Flavanol glucosides from rhubarb and Raphiolepis imbellata. Phytochemistry 22: 1659 (1983).Google Scholar
  77. 77.
    Doskotch, R.W.; Mikhail, A.A.; Chatterjii, S.J. Structure of the water-soluble feeding stimulant for Scolytus multistriatus. A revision. Phytochemistry 12: 1153 (1973).CrossRefGoogle Scholar
  78. 78.
    Karl, C.; Muller, G.; Pederson, P.A. Ein neues Catechinglycosid aus Polypodium vulgare. Z. Naturforsch. 37c: 148 (1982).Google Scholar
  79. 79.
    Kashiwada, Y.; Nonaka, G.; Nishioka, I. Tannins and related compounds. XLV. Rhubarb (5). Isolation and characterization of flavan-3-ol and procyanidin glucosides. Chem. Pharm. Bull. 34: 3208 (1986).Google Scholar
  80. 80.
    Morimoto, S.; Nonaka, G.; Nishioka, I. Tannins and related compounds. XXXVIII. Isolation and characterization of flavan-3-o1 glucosides and procyanidin oligomers from cassia bark Cinnamomum cassia Blume). Chem. Pharm. Bull. 34: 633 (1986).CrossRefGoogle Scholar
  81. 81.
    Nonaka, G.; Nishioka, I. Novel biflavonoids, chalcan-flavan dimers from Gambir. Chem. Pharm. Bull. 28: 3145 (1980).CrossRefGoogle Scholar
  82. 82.
    Nonaka, G.; Nishimura, H.; Nishioka, I. Tannins and related compounds. Part 26. Isolation and structures of stenophyllanins A, B, and C, novel tannins from Quercus stenophylla. J. Chem. Soc. Perkin Trans. 1: 163 (1985).CrossRefGoogle Scholar
  83. 83.
    Bohlmann, F.; Zdero, C.; King, R.M.; Robinson, H. New prenylflavanoids from Marshal lia grandiflora. Phytochemistry 18: 1246 (1979).Google Scholar
  84. 84.
    Gomez, F.; Quijano, L.; Calderon, J.S.; Rodriquez, C.; Tios, T. Prenylflavans from Tephrosia watsoniana. Phytochemistry 24: 1057 (1985).CrossRefGoogle Scholar
  85. 85.
    Bohlmann, F.; Jakupovic, J.; King, R.M.; Robinson, H. Chromones and flavans from Marshallia obovata. Phytochemistry 19: 1815 (1980).CrossRefGoogle Scholar
  86. 86.
    Homberger, K.; Hesse, M. Kopsirachin, ein ungewohnliches Alkaloid aus der Apocynacea Kopsia dasyrachis Ridl. Helv. Chim. Acta 67: 237 (1984).CrossRefGoogle Scholar
  87. 87.
    Shen, Z.; Haslam, E.; Falshaw, C.P.; Begley, M.J. Procyanidins and polyphenols of Larix gmelini bark. Phytochemistry 25: 2629 (1986).CrossRefGoogle Scholar
  88. 88.
    Ferreira, D.; duPreez, I.C.; Wijnmaalen, J.C.; Roux, D.G. Biflavanoid proguibourtinidin carboxylic acids and the biflavanoid homologues from Acacia luderitzii. Phytochemistry 24: 2415 (1985).CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1989

Authors and Affiliations

  • G. Wayne McGraw
    • 1
  1. 1.Department of ChemistryLouisiana CollegePinevilleUSA

Personalised recommendations