Montreal, Canada, June 15-20, 1986

Frontmatter -- Preface / Cooper, Bernard A. / Whitehead, V. Michael -- Acknowledgments -- Contents -- How it all Began: A Brief History of the Pteridine Symposia / Albert, Adrien -- The Gowland Hopkins Lecture: The Mechanisms of Action of Folate and Pterin Requiring Enzymes / Benkovic, S.J. / Slieker, L.J. / Daubner, S.C. / Courtney, L.F. / Dix, T.A. / Pember, S.O. / Bloom, L.M. / Fierke, C.A. / Mayer, R.J. / Chen, J.-T. / Taira, K. -- Section A: Chemistry of Pterins and Folates -- Side-Chain Chemistry of Pteridines / Pfleiderer, W. / Kang, Y. / Soyka, R. / Hutzenlaub, W. / Wiesenfeldt, M. / Leskopf, W. -- A General Method for the Synthesis of 10-Substituted-10-Deaza Folate Analogues / Nair, M.G. / Toghiyani, Tahereh R. / Ramamurthy, B. / Kisliuk, R.L. / Gaumont, Y. -- Synthesis and Properties of Pyrimidodiazepines as Ring-Strained Probes of Pterin Utilizing Enzymes / Bailey, S.W. / Pike, D.C. / Ayling, J.E. -- Summary: Pterin and Folate Chemistry / Taylor, E. C. -- A Facile Method for Preparing 2,4-Diamino-5,8-Dideazapterins / Hynes, J.B. / Pathak, A. / Panos, C.H. / Okeke, C.C. -- Synthesis of 5,10-Dideaza-5,6,7,8-Tetrahydrofolic Acid (DDATHF) and Analogs / Taylor, Edward C. / Wong, George S. K. / Fletcher, Stephen R. / Harrington, Peter J. / Beardsley, G. Peter / Shih, Chuan J. -- Synthetic Routes to Methotrexate- and Folic Acid-Polyglutamates of High Chemical and Enantiomeric Purity / Przybylski, M. / Renkel, R. / Fonrobert, P. -- In Vivo and In Vitro Evaluations of 5-[4-(Substituted Aryl)-1- Piperazinyl]-6-Alkyl-2,4-Pyrimidinediamines as Antitumor Agents / Werbel, L.M. / Hung, J. / Besserer, J.A. / Boritzki, T.J. / Leopold, W.R. / Fry, D.W. -- The Electrochemical Oxidation of Tetrahydropterin Derivatives / Kwee, S. -- A Practical Synthesis of (6R)- and (6S)-5,6,7,8-Tetrahydrobiopterins / Matsuura, Sadao / Sugimoto, Takashi / Murata, Shizuaki -- Chemical Synthesis and Properties of Quinonoid (6R)-Dihydrobiopterin / Matsuura, Sadao / Murata, Shizuaki / Sugimoto, Takashi -- Pyrazine-Ring Conformations of Tetrahydropterins and Quinonoid-Dihydropterins / Gready, J. E. -- Hydrogenation of Silylated Pterins in Benzene Solution / Boyle, P.H. / Kelly, M.J. -- N(5)-Alkylation of Polyacetylated 5,6,7,8-Tetrahydroneopterins / Antoulas, S. / Viscontini, M. -- Oxidations Photosensitized by Pterins and Diaminopteridines / Aubailly, M. / Santus, R. -- Structure of the Riboflavin Synthase/Lumazine Synthase Complex. Arrangement and Chain Folding of Subunits in the Icosahedral Capsid / Ladenstein, R. / Bartunik, H. D. / Schneider, M. / Huber, R. / Schott, K. / Bacher, A. -- Use of C18 Silica Cartridges to Purify and Characterize Pterins / Jacobson, K. Bruce / Ferre, J. -- Synthesis and Structure-Activity Relationships of Tetrahydrobiopterin Cofactor Analogues / Bigham, E. C. / Smith, G. K. / Reinhard, J. F. -- Synthesis, Purification and Properties of a New Class of Pteridine Derivatives / Ferré, J. / Yim, J. J. / Pfleiderer, W. / Jacobson, K.B. -- Summary: Chemistry of Pterins / Hynes, John B. -- Section B: Biosynthesis and Biochemistry of Pterins -- Biosynthesis of Tetrahydrobiopterin and Related Compounds in Drosophila melanogaster / Brown, G.M. / Primus, J.P. / Switchenko, A.C. -- Tetrahydrobiopterin Biosynthesis in Man / Curtius, H.-Ch. / Takikawa, S. / Niederwieser, A. / Ghisla, S. -- The Biosynthesis of Tetrahydrobiopterin in the Bovine Adrenal Medulla / Smith, Gary K. / Duch, David S. / Nichol, Charles A. -- The Biosynthesis of Tetrahydrobiopterin in Rat Brain / Milstien, Sheldon / Kaufman, Seymour -- Summary: Biosynthesis of Tetrahydrobiopterin / Brown, G.M. -- The Metabolic Role of Tetrahydrobiopterin / Kaufman, Seymour -- Spectroscopic Studies on Tyrosine 3-Monooxygenase from Bovine Adrenal Medulla: A Blue Iron Protein / Haavik, J. / Andersson, K.K. / Petersson, L. / Flatmark, T. -- Queuine-Lacking tNRAs in Relation to the Grade of Malignancy of Specific Tumors, Possible Role of Pteridines / Kersten, W. / Zubrod, E. / Emmerich,