A forty-year journey in plant research: Original contributions to flavonoid biochemistry

Canadian Journal of Botany

Volumn 83, Issue 5, 2005, Pages 433-450

  Ibrahim, Ragai K ^a  

^a Gina Cody School of Engineering and Computer Science   (Canada)

Author keywords

3 D structure; Flavonoid enzymology; Gene cloning; Metabolite localization; Phylogeny

Indexed keywords

AROMATIC COMPOUNDS; BIOCHEMISTRY; BIOSYNTHESIS; CLONING; DRUG PRODUCTS; ENZYMES; GENES;

ENZYMATIC PRENYLATION; FLAVONOID BIOCHEMISTRY; GLUCOSYLTRANSFERASES; METHYLTRANSFERASES;

PLANTS (BOTANY);

BIOCHEMISTRY;

BIOCHEMISTRY; BIOSYNTHESIS; CLONES; DRUGS; ENZYMES; FLAVONOIDS; GENES; PLANTS;

EID: 23144456311     PISSN: 00084026     EISSN: None     Source Type: Journal    
DOI: 10.1139/b05-030     Document Type: Review

References (120)

1. Ananvoranich, S., Varin, L., Gulick, P., and Ibrahim, R.K. 1994. Cloning and regulation of flavonol 3-sulfotransferase in cell suspension cultures of Flaveria bidentis. Plant Physiol. 106: 485-491.
2. Anzellotti, D., and Ibrahim, R.K. 2000. A novel flavonol 2-oxoglutarate-dependent dioxygenase: affinity purification, characterization and kinetin properties. Arch. Biochem. Biophys. 382: 161-172.
3. Anzellotti, D., and Ibrahim, R.K. 2004. Molecular characterization and functional expression of flavonol 6-hydroxylase. BMC Plant Biol. [online] 4: 20. doi: 10.1186/1471-2229-4-20
4. Bajaj, K.L., De Luca, V., Khouri, H.E., and Ibrahim, R.K. 1983. Partial purification and properties of flavonol ring-B O-glucosyltransferases from Chrysosplenium americanum. Plant Physiol. 72: 891-896.
5. Bantignies, B., Séguin, J., Muzac, I., Dédaldéchamp, F., Gulick, P.J., and Ibrahim, R.K. 2000. Direct evidence for ribonucleolytic activity of a PR-10-like protein from white lupin roots. Plant Mol. Biol. 42: 871-881.
6. Barron, D., and Ibrahim 1986. Novel flavonol sulfates from Flaveria chloraefolia. Bull. Liaison Groupe Polyphenols, 13: 540-545.
7. Barron, D., and Ibrahim, R.K. 1987a. Quercetin- and patuletin 3,3′-disulfates from Flaveria chloraefolia. Phytochemistry, 26: 1181-1184.
8. Barron, D., and Ibrahim, R.K. 1987b. 6-Methoxyflavonol 3-monosulfates from Flaveria chloraefolia. Phytochemistry, 26: 2085-2088.
9. Barron, D., and Ibrahim, R.K. 1987c. Synthesis of flavonoid sulfates. I. Stepwise sulfation of positions 3, 7 and 4′ using N,N′- dicyclohexylcarbodiimide and tetrabutylammonium hydrogen sulfate. Tetrahedron, 43: 5197-5202.
10. Barron, D., and Ibrahim, R.K. 1988a. Synthesis of flavonoid sulfates. II. The use of aryl sulfatase in the synthesis of flavonol 3-sulfates. Z. Naturforsch. 43c: 625-630.
11. Barron, D., and Ibrahim, R.K. 1988b. Synthesis of flavonoid sulfates. III. Synthesis of 3′,4′-o-disulfates using sulfur trioxide-trimethylamine complex and of 3′-sulfates using aryl sulfatase. Z. Naturforsch. 43c: 631-635.
12. Barron, D., and Ibrahim, R.K. 1988c. Hydrochloric acid and aryl sulfatase as reagents for uv spectral detection of 3- and 4′-sulfated flavonoids. Phytochemistry, 27: 2335-2338.
13. Barron, D., and Ibrahim, R.K. 1988d;. Ombuin 3-sulfate from Flaveria chloraefolia. Phytochemistry, 27: 2362-2363.
14. Barron, D., and Ibrahim, R.K. 1996. Isoprenylated flavonoids: a survey. Phytochemistry, 43: 921-982.
15. Barron, D., Colebrook, L., and Ibrahim, R.K. 1986. An equimolar mixture of quercetin 3-sulfate and patuletin 3-sulfate from Flaveria chloraefolia. Phytochemistry, 25: 1719-1721.
16. Barron, D., Varin, L., Ibrahim, R.K., Harborne, J.B., and Williams, A.C. 1988. Sulfated flavonoids: an update. Phytochemistry, 27: 2375-2395.
17. Bohm, B.A. 1998a. Flavonoid functions in nature. In Introduction to flavonoids. Chemistry and biochemistry of organic natural products. Vol. 2. Edited by B.A. Bohm. Harwood Academic Publishers, Amsterdam. pp. 339-364.
18. Bohm, B.A. 1988b. Human uses of flavonoids. In Introduction to flavonoids. Chemistry and biochemistry of organic natural products. Vol. 2. Edited by B.A. Bohm. Harwood Academic Publishers, Amsterdam. pp. 365-393.
19. Brisson, L., Vacha, W., and Ibrahim, R.K. 1986. Localization of partially methylated flavonol glucosides in Chrysosplenium americanum. II. Immunofluorescense. Plant Sci. 44: 559-605.
20. Brisson, L., Rideau, M., and Ibrahim, R.K. 1988. Tissue culture of Chrysosplenium americanum and its potential for flavonoid production. Plant Cell Rep. 7: 130-133.
21. Brunet, G., and Ibrahim, R.K. 1980. O-Methylation of flavonoids by cell-free extracts of calamondin orange. Phytochemistry, 19: 741-746.
22. Cacace, S., Schröder, G., Wehinger, E., Strack, D., and Schmidt, J., and Schröder, J. 2003. A flavonol O-methyltransferase from Catharanthus roseus performing two sequential methylations. Phytochemistry, 62: 127-137.
23. Charest, P.-M., Brisson, L., and Ibrahim, R.K. 1986. Ultrastructural features of flavonoid accumulation in leaf cells of Chrysosplenium americanum. Protoplasma, 134: 95-101.
24. Chavadej, S., Brisson, N., McNeil, J.N., and De Luca, V. 1994. Redirection of tryptophan leads to production of low indole glucosinolate canola. Proc. Natl. Acad. Sci. U.S.A. 91: 2166-2170.
25. Chrispeels, M.J. 1980. The endoplasmic reticulum. In The biochemistry of plants. Vol. 1. Edited by N.E. Tolbert. Academic Press, New York. pp. 389-412.
26. Collins, F.W., De Luca, V., Ibrahim, R.K., Voirin, B., and Jay, M. 1981. Polymethylated flavonol synthesis in Chrysosplenium americanum: identification and enzymatic synthesis. Z. Naturforsch. 36c: 730-736.
27. De Carolis, E., and Ibrahim, R.K. 1989. Purfication and kinetics of two phenylpropanoid O-methyltransferase activities from Brassica oleracea. Biochem. Cell Biol. 67: 763-769.
28. De Luca, V., and Ibrahim, R.K. 1982. Characterization of three distinct O-methyltransferases from Chrysosplenium americanum. Phytochemistry, 21: 1537-1540.
29. De Luca, V., and Ibahim, R.K. 1985a. Enzymatic synthesis of polymethylated flavonols in Chrysosplenium americanum. I. Partial purification and some properties of S-adenosyl-L-methionine:flavonol 3-, 6-, 7-, and 4′-O-methyltransferases. Arch. Biochem. Biophys. 238: 595-605.
30. De Luca, V., and Ibrahim, R.K. 1985b. Enzymatic synthesis of polymethylated flavonols in Chrysosplenium americanum. II. Substrate interaction and product inhibition studies of flavonol 3-, 6- and 4′-O- methyltransferases. Arch. Biochem. Biophys. 238: 606-618.
31. Dixon, R.A. 1999. Isoflavonoids. In Comprehensive natural products chemistry. Vol. 1. Edited by U. Sankawa. Elsevier, Amsterdam. pp. 773-823.
32. Eisen, J.A., and Wu, M. 2002. Phylogenetic analysis and gene functional prediction: phylogenomics in action. Theor. Popul. Biol. 61: 481-487.
33. Forkmann, G., and Heller, W. 1999. Biosynthesis of flavonoids. In Comprehensive natural products chemistry. Vol. 1. Edited by U. Sankawa. Elsevier, Amsterdam. pp. 713-748.
34. Forkmann, G., and Martens, S. 2001. Metabolic engineering and applications of flavonoids. Curr. Opin. Biotechnol. 12: 155-160.
35. Gagnon, H., and Ibrahim, R.K. 1997. Effects of various elicitors on the accumulation and secretion of isoflavonoids in white lupin. Phytochemistry, 44: 1463-1467.
36. Gagnon, H., and Ibrahim, R.K. 1998. Aldonic acids: a novel family of nod gene inducers of Mesorhizobium loti, Rhizobium lupini and Sinorhizobium meliloti. Mol. Plant-Microbe Interact. 11: 988-998.
37. -14C]L-phenylalanine and their release into the culture medium. Plant Physiol. 100: 76-79.
38. Gagnon, H., Tahara, S., Bleichert, E., and Ibrahim, R.K. 1992b. Separation of aglycones, glucosides and prenylated isoflavones by high-performance liquid chromatography. J. Chromatogr. 606: 255-259.
39. Gagnon, H., Grandmaison, J., and Ibrahim, R.K. 1995. Phytochemical and immunocytochemical evidence for the accumulation of 2′-hydroxylupalbigenin in lupin nodules and bacteroids. Mol. Plant-Microbe Interact. 8: 131-137.
40. Gang, D.R., Lavid, N., Zubieta, C., Che, F., Beuerle, T., Lewinsohn, E., Noel, J.P., and Pichersky, E. 2002. Characterization of phenylpropene O-methyltransferases from sweet basil: facile change of substrate specificity and convergent evolution within a plant O-methyltransferase family. Plant Cell, 14: 505-519.
41. Gauthier, A., Gulick, P.J., and Ibrahim, R.K. 1996. cDNA cloning and characterization of a 3′/5′-O-methyltransferase for a partially methylated flavonol from Chrysosplenium americanum. Plant Mol. Biol. 36: 1163-1169.
42. Gauthier, A., Gulick, P.J., and Ibrahim, R.K. 1998. Characterization of two cDNA clones which encode O-methyltransferases for the methylation of boh flavonoid and phenylpropanoid compounds. Arch. Biochem. Biophys. 351: 243-249.
43. Grandmaison, J., and Ibrahim, R.K. 1995. Ultrastructural localization of a diprenylated isoflavone in Rhizobium lupini - Lupinus albus symbiotic association. J. Exp. Bot. 46: 231-237.
44. Hallard, D., Bleichert, E., Gagnon, HY., Tahara, S., and Ibrahim, R.K. 1992. Production and release of isoflavonoids in lupin cell cultures. Z. Naturforsch. 47c: 346-352.
45. Hannoufa, A., Varin, L., and Ibrahim, R.K. 1991. Spatial distribution of flavonoid conjugates and their enzymes in Flaveria bidentis. Plant Physiol. 97: 259-263.
46. Hannoufa A., Brown, R.H., and Ibrahim, R.K. 1994. Variations in flavonoid sulfate patterns in relation to photosynthetic types of five Flaveria species. Phytochemistry, 36: 353-356.
47. Hollman, P.C., and Katan, M.B. 1998. Bioavailability and health effects of dietary flavonols in man. Arch. Toxicol. 20: 237-248.
48. Holton, T.A., and Cornish, B.C. 1995. Genetics and biochemistry of anthocyanin biosynthesis. Plant Cell, 7: 1071-1083.
49. Huang, T.-S., Anzellotti, D., Dédaldéchamp, F., and Ibrahim, R.K. 2004. Partial purification, kinetin analysis and amino acid sequence information of a flavonol 3-O-methyltransferase from Serratula tinctoria. Plant Physiol. 134: 1366-1376.
50. Ibrahim, R.K. 1964. Biosynthesis of hydroxybenzoic acids in plants. Biochem. Physiol. Pflanzen, 154: 481-489.
51. Ibrahim, R.K. 1977. Glucosylation of lignin precursors by UDP-glucose:coniferyl alcohol glucosyltransferase in higher plants. Z. Pflanzenphysiol. 85: 253-262.
52. Ibrahim, R.K. 1990. Immunocytochemical localization of plant secondary metabolites and the enzymes involved in their biosynthesis. Phytochem. Anal. 1: 49-59.
53. Ibrahim, R.K. 1992. Immunolocalization of flavonoid conjugates and their enzymes. In Phenolic metabolism in plants. Edited by H. Stafford and R.K. Ibrahim. Plenum Press, New York. pp. 25-61.
54. Ibrahim, R.K. 1997. Plant O-methyltransferase signatures. Trends Plant Sci. 2: 249-250.
55. Ibrahim, R.K., and Anzellotti, D. 2003. The enzymatic basis of flavonoid biodiversity. In Integrative phytochemistry: from ethnobotany to molecular ecology. Edited by J.T. Romeo. Pergamon, Amsterdam. pp. 1-36.
56. Ibrahim, R.K., and Grisebach, H. 1976. Partial purification and properties of UDP-glucose:coniferyl alcohol glucosyltransferase from Paul's scarlet rose cell suspension cultures. Arch. Biochem. Biophys. 176: 700-708.
57. Ibrahim, R.K., and Muzac, I. 2000. The methyltransferase gene superfamily: a tree with multiple branches. In Evolution of metabolic pathways. Edited by J.T. Romeo, R.K. Ibrahim, L. Varin, and V. De Luca. Pergamon Press, Amsterdam. pp. 349-384.
58. 14C, in higher plant. Nature (London), 184: 1803-1804.
59. Ibrahim, R.K., and Towers, G.H.N. 1960a. The identification, by chromatography, of plant phenolic acids. Arch. Biochem. Biophys. 87: 125-128.
60. 14C]labeled compounds. Can. J. Biochem. Physiol. 38: 627-634.
61. 14C]L-tyrosine in some higher plants. Can. J. Biochem. Physiol. 39: 873-880.
62. 14C]labeled compounds. Can. J. Biochem. Physiol. 40: 449-453.
63. Ibrahim, R.K., and Varin, L. 1993. Flavonoid enzymology. In Methods in plant biochemistry. Vol 9. Edited by P.J. Lea. Academic Press, London. pp. 99-131.
64. Ibrahim, R.K., Bohm, B.A., and Towers, G.H.N. 1961. The partial elucidation of the structure of a new coumarin from Hydrangea macrophylla. Can. J. Biochem. Physiol. 39: 1389-1395.
65. Ibrahim, R.K., Towers, G.H.N., and Gibbs, D.R. 1962. Syringic and sinapic acids as indicators of differences between major groups of vascular plants. J. Linn. Soc. Lond. Bot. 58: 223-230.
66. Ibrahim, R.K., De Luca, V., Khouri, H., Latchinian, L., Brisson, L., and Charest, J.-P. 1987. Enzymology and compartmentation of polymethylated flavonol glucosides in Chrysosplenium americanum. Phyochemistry, 26: 1237-1245.
67. Ibrahim, R.K., Chavadej, S., and De Luca, V. 1994. Engineering altered glucosinolate biosynthesis by two alternate strategies. In Genetic engineering of plant secondary metabolism. Edited by B.E. Ellis, G.W. Kuroki, and H.E. Stafford. Plenum Press, New York. pp. 125-152.
68. Ibrahim, R.K., Bruneau, A., and Bantignies, B. 1998. Plant O-methyltransferases: molecular analysis, common signature and classification. Plant Mol. Biol. 36: 1-10.
69. Jay, M., De Luca, V., and Ibrahim, R.K. 1982. Meta-Methylation of rings A (8-) and B (3′-) is catalyzed by two distinct O-methyltransferases in Lotus corniculatus. Z. Naturforsch. 38: 413-417.
70. Jay, M., De Luca, V., and Ibrahim, R.K. 1985. Purification, properties and kinetic mechanism of flavonol 8-O-methyltransferase from Lotus corniculatus. Eur. J. Biochem. 153: 321-325.
71. Khouri, H.E., and Ibrahim, R.K. 1984. Kinetic mechanism of a flavonol ring-B O-glucosyltransferase from Chrysosplenium americanum. Eur. J. Biochem. 142: 559-564.
72. Khouri, H.E., and Ibrahim, R.K. 1987. Resolution of five position-specific O-methyltransferases by fast-protein liquid chromatofocusing. J. Chromatogr. 407: 291-297.
73. Khouri, H.E., Ishikura, N., and Ibrahim, R.K. 1986. FPLC purification and some properties of a partially methylated flavonol glucoside 2′-/5′-O-methyltransferase from Chrysosplenium americanum. Phytochemistry, 25: 2475-2479.
74. Khouri, H.E., De Luca, V., and Ibrahim, R.K. 1988a. Enzymatic synthesis of polymethylated flavonols in Chrysosplenium americanum. III. Purification and kinetic analysis of S-sdenosyl-L-methionine:3-methylquercetin 7-O-methyltransferase. Arch. Biochem. Biophys. 265: 1-7.
75. Khouri, H.E., Tahara, S., and Ibrahim, R.K. 1988b. Partial purification, characterization and kinetic analysis of isoflavone 5-O-methyltransferase from yellow lupin roots. Arch. Biochem. Biophys. 262: 592-598.
76. Kornblatt, J., Muzac, I., Lim, Y., Ahn, J.H., and Ibrahim, R.K. 2004. Role of Ser286 in cosubstrate binding and catalysis of a flavonol O-methyltransferase. Biochem. Cell Biol. 82: 531-537.
77. Kurowska, E.M., and Manthey, J.A. 2004. Hypolipidemic effects and absorption of citrus polymethoxylated flavones in hamsters with diet-induced hyperchloesterolemia. J. Agric. Food Chem. 52: 2879-2886.
78. Laflamme, P., Khouri, H.E., Gulick, P.J., and Ibrahim, R.K. 1993. Enzymatic prenylation of isoflavones in white lupin. Phytochemistry, 34: 147-151.
79. Lam, K., Dayanandan, S., and Ibrahim, R.K. 2004. Phylogenomic analysis of plant O-methyltransferases. In Proceedings of the XXII International Conference on Polyphenols, Helsinki, Finland, 25-28 August 2004. Edited by A. Hoikkala and O. Soidinsalo. University of Helsinki, Helsinki. pp. 497-498.
80. Lamoureux, S., Vacha, W., and Ibrahim, R.K. 1986. Localization of partially methylated flavonol glucosides in Chrysosplenium americanum. I. Preparation and some properties of an anti-trimethylflavonol glucoside antibody. Plant Sci. 44: 169-173.
81. Latchinian, L., and Ibrahim, R.K. 1989. Characterization of a monoclonal antibody specific to a flavonol ring-B O-glucosyltransferase. Biochem. Cell Biol. 67: 210-213.
82. Latchinian, L., and Ibrahim, R.K. 1991. Flavonol ring-B O-glucosyltransferase: purification, production of polyclonal antibodies and immunolocalization. Arch. Biochem. Biophys. 289: 230-236.
83. Latchinian, L., Khouri, H.E., and Ibrahim, R.K. 1987. Fast protein affinity chromatography of two flavonol O-glucosyltransferases. J. Chromatogr. 388: 235-242.
84. Macheix, J.-J., and Ibrahim, R.K. 1984. The O-methyltransferase system of apple fruit cell suspension culture. Biochem. Physiol. Pflanzen. 179: 659-664.
85. Manthey, J.A., Guthrie, N., and Grohmann, K. 2001. Biological properties of citrus flavonoids pertaining to cancer and inflammation. Curr. Med. Chem. 8: 135-153.
86. Marchand, L., Charest, P.-M., and Ibrahim, R.K. 1987. Localization of methylated flavonol glucosides in Chrsosplenium americanum. III. Immunogold labeling. J. Plant Physiol. 131: 339-348.
87. Middleton, E., Jr., and Kandaswamy, C. 1994. The impact of plant flavonoids on mammalian biology: implications for immunity, inflammation and cancer. In The flavonoids - advances in research since 1986. Edited by J.B. Harborne. Chapman & Hall, London. pp. 619-652.
88. Muzac, I., Wang, J., Anzellotti, D., Zhang, H., and Ibrahim, R.K. 2000. Functional expression of an Arabiodopsis cDNA clone encoding flavonol 3′-O-methyltransferase and characterization of the gene product. Arch. Biochem. Biophys. 375: 385-388.
89. N'Dong, C., Anzellotti, D., Ibrahim, R.K., Huner, N., and Sarhan, F. 2003. Daphnetin methylation by a novel O-methyltransferase is associated with cold acclimation and photosystem II excitation pressure in rye. J. Biol. Chem. 278: 6854-6861.
90. Piotrowski, M., Schemenewitz, A., Lopukhina, A., Müller, A., Janowitz, T., Weiler, E.W., and Oecking, C. 2004. Desulfoglucosinolate sulfotransferases from Arabidopsis thaliana catalyze the final step in the biosynthesis of the glucosinolate core structure. J. Biol. Chem. 279: 50717-50725.
91. Pople, J.A., and Beveridge, D. 1970. Approximate molecular orbital theory. McGraw-Hill, New York.
92. Rice-Evans, C.A., and Miller, N.J. 1996. Antioxidant activity of flavonoids as bioactive compounds. Biochem. Soc. Trans. 24: 790-794.
93. Roda, A.L., Oldham, N.J., Svatos, A., and Baldwin, I.T. 2003. Allometric analysis of the induced flavonols on the leaf surface of wild tobacco (Nicotiana attenuata). Phytochemistry, 62: 527-536.
94. Schijlen, E.G., de Vos, C.H., van Tunen, A.J., and Bovy, A.G. 2004. Modification of flavonoid biosynthesis in crop plants. Phytochemistry, 65: 2631-2648.
95. Schröder, G., Wehinger, E., Lukacin, R., Wellmann, F., Seefelder, W., Schwab, W., and Schröder, J. 2004. Flavonoid methylation: a novel 4′-O-methyltransferase from Catharanthus roseus, and evidence that partially methylated flavanones are substrates of four different flavonoid dioxygenases. Phytochemistry, 65: 1085-1094.
96. Schubert, H.L., Blumenthal, R.M., and Cheng, X. 2003. Many paths to methyl transfer: a chronicle of convergence. Trends Biochem. Sci. 28: 329-335.
97. Séguin, J., Muzac, I., and Ibrahim, R.K. 1998. Purification and immunological characterization of a recombinant trimethylflavonol 3′-O-methyltransferase. Phytochemistry, 49: 319-325.
98. Stafford, H.A. 1990. Flavonoid metabolism. CRC Press, Boca Raton, Fla.
99. Tahara, S., and Ibrahim, R.K. 1995. Prenylated isoflavonoids: an update. Phytochemistry 38: 1073-1094.
100. Thresh, K.,and Ibrahim, R.K. 1985. Are spinach chloroplasts involved in flavonoid O-methylation? Z. Naturforsch. 40c: 331-335.
101. Tsang, Y.-F., and Ibrahim, R.K. 1979. Evidence for the existence of meta- and para-directing O-methyltransferases in tobacco cell cultures. Z. Naturforsch. 34c: 46-50.
102. VanEtten, H.D., Mansfield, J.W., Bailey, J.A., and Farmer, E.E. 1994. Two classes of plant antibiotics: phytoalexins versus "phytoanticipins". Plant Cell, 6: 1191-1192.
103. Varin, L. 1992. Flavonoid sulfation: Phytochemistry, enzymology and molecular biology. In Phenolic metabolism in plants. Edited by H. Stafford and R.K. Ibrahim. Plenum Press, New York. pp. 233-254.
104. Varin, L., and Ibrahim, R.K. 1989. Partial purification and characterization of three flavonol-specific sulfotransferases from Flaveria chloraefolia. Plant Physiol. 90: 977-981.
105. Varin, L., and Ibrahim, R.K. 1991. Partial purification and some properties of flavonol 7-sulfotransferase from Flaveria bidentis. Plant Physiol. 95: 1858-1863.
106. Varin, L., and Ibrahim, R.K. 1992. Novel flavonol 3-sulfotransferase: purification, kinetic properties and partial amino acid sequence. J. Biol. Chem. 267: 1858-1863.
107. Varin, L., Barron, D., and Ibrahim. 1986. Identification and biosynthesis of sulfated and glucosylated flavonols in Flaveria bidentis. Z. Naturforsch. 41c: 813-819.
108. Varin, L., Barron, D., and Ibrahim, R.K. 1987a. Enzymatic assay of flavonoid sulfotransferase. Anal. Biochem. 161: 176-180.
109. Varin, L., Barron, D., and Ibrahim, R.K. 1987b. Enzymatic synthesis of sulphated flavonoids in Flaveria spp. Phytochemistry, 26: 135-138.
110. Varin, L., De Luca, V., Ibrahim, R.K., and Brisson, N. 1992. Moecular characterization of two plant flavonol sulfotransferases. Proc. Natl. Acad. Sci. U.S.A. 89: 1286-1290.
111. Vitali, A., Giardina, B., Monache, G.D., Rocca, F., Silvestrini, A., Tafi, A., and Botta, B. 2003. Chalcone dimethylallyltransferase from Morus nigra cell cultures: substrate specificity studies. FEBS Lett. 557: 33-38.
112. Willits, M.G., Giovanni, M., Prata, R.T.N., Kramer, C.M., De Luca, V., Steffens, J.C., and Graser, G. 2004. Biofermentation of modified flavonoids: an example of in vivo diversification of secondary metabolites. Phytochemistry, 65: 31-41.
113. Winkel-Shirley, B. 2001. Flavonoid biosynthesis: a colorful model for genetics, biochemistry, cell biology and biotechnology. Plant Physiol. 126: 485-493.
114. Yang, E.B., Zhao, Y.N., Zhang, K., and Mack, P. 1999. Daphnetin, one of the coumarin derivatives, is a protein kinase inhibitor. Biochem. Biophys. Res. Commun. 260: 682-685.
115. Yang, H., Ahn, J.-H., Ibrahim, R.K., Lee, S., and Lim, Y. 2004. The three-dimensional structure of Arabidopsis thaliana O-methyltransferase by homology-based modelling. J. Mol. Graph. Model. 23: 77-87.
116. Yazaki, K., Kunihisha, M., Fujisaki, T., and Sato, F. 2002. Geranyl diphosphate: 4-hydroxybenzoate geranyltransferase from Lithospermum erythrorhizon. J. Biol. Chem. 277: 6240-6246.
117. Zhang, H., Wang, J., and Goodman, H.M. 1997. An Arabisopsis gene encoding a putative 14-3-3-interacting protein, a caffeic acid/5-hydroxyferulic acid O-methyltransferase. Biochim. Biophys. Acta, 1353: 199-202.
118. Zhu, B.T., Enzell, E.L., and Liehr, J.G. 1994. Catechol O-methyltransferase-catalyzed rapid O-methylation of mutagenic flavonoids: metabolic inactivation as a possible reason for their lack of carcinogenicity in vivo. J. Biol. Chem. 269: 292-299.
119. Zubieta, C., He, X.-Z., Dixon, R.A., and Noel, J.P. 2001. Structures of two natural product methyltransferases reveal the basis for substrate specificity in plant O-methyltransferases. Nat. Struct. Biol. 8: 271-279.
120. Zubieta, C., Kota, P., Ferrer, J.L., Dixon, R.A., and Noel, J.P. 2002. Structural basis for the modulation of lignin monomer methylation by caffeic acid/5-hydroxyferulic acid 3/5-O-methyltransferase. Plant Cell, 14: 1265-1277.