Ian D. Spenser Professor Emeritus B.Sc. (Birmingham), Ph.D., D.Sc. (London), F.R.S.C., F.R.S.C. (U.K.), F.C.I.C. Biosynthesis Contact Information

---

     The general area of research is the investigation, by means of tracer methods, of the biosynthesis of natural products containing nitrogen.

     Whereas in earlier years sole emphasis was placed on attempts to develop and confirm biogenetic hypotheses by demonstrating non-random incorporation of radioactivity from singly ¹⁴C-labelled substrates into predicted positions of biosynthetic products (e.g., Vitamin B₁, Vitamin B₆, Ephedrine) and to establish thereby that the substrate served as a specific precursor of the products, an additional thrust of current work is leading in several new directions. Among these are:

• the exploitation of multiply labelled substrates (e.g., ¹³C + ¹³C, ¹³C + ²H, assayed by ¹³C and ²H NMR) in attempts to demonstrate intact incorporation of multicarbon fragments;

• the development of probes for the detection and recognition of intermediates between primary precursors and end product;

• development of methods for the investigation of stereochemical aspects of biosynthesis, and, in particular, the chirality and prochirality of precursor-product relationships and of enzyme catalyzed reactions.

     Natural products containing piperidine, pyridine, pyrimidine and purine ring systems serve as vehicles for these methods. Current work focusses on the origin of the two B-vitamins, Thiamin (B₁) and Pyridoxine (B₆).

Research Group (as of November, 2003)

Research Associates:

R.N. Gupta, Ph.D. (McMaster University)


Johannes Zeidler, Dr. rer. nat. (Karlsruhe)

Research Technician:

Richard M. Pauloski, B.Sc. (McMaster University)

Selected Publications:

• J. Zeidler^*, B. G. Sayer and I. D. Spenser
  "Biosynthesis of Vitamin B₁ in yeast. Derivation of the pyrimidine unit from pyridoxine and histidine. Intermediacy of urocanic acid."
  J. Am. Chem. Soc., 125, 13094-13105 (2003).

• J. Zeidler^*, R. N. Gupta, B. G. Sayer and I. D. Spenser
  "Biosynthesis of Vitamin B₆ in yeast. Incorporation pattern of trioses."
  J. Org. Chem., 68, 3486-3493 (2003).

• N. Ullah^*, J. Zeidler and I. D. Spenser
  "Deuterium-labeled 2'-Hydroxypyridoxol."
  SYNLETT No. 9, 1344-1348 (2003).

• J. Zeidler, N. Ullah, R.N. Gupta, R.M. Pauloski, B.G. Sayer and I.D. Spenser
  "2'-Hydroxypyridoxol, a biosynthetic precursor of Vitamins B₆ and B₁ in yeast."
  J. Am. Chem. Soc., 124, 4542-4543 (2002).

• R.N. Gupta, T. Hemscheidt, B.G. Sayer and I.D. Spenser
  "Biosynthesis of Vitamin B₆ in yeast. Incorporation pattern of glucose."
  J. Am. Chem. Soc., 123, 11353-11359 (2001).

• R.N. Gupta, T. Hemscheidt, B.G. Sayer and I.D. Spenser
  "Incorporation of ¹³C glucose into nicotinamide in E. coli and in S. cerevisiae."
  Can. J. Chem. 79, 418 - 425 (2001).

• D.E. Cane, S. Du, and I.D. Spenser
  "Biosynthesis of Vitamin B₆: Origin of the oxygen atoms of pyridoxol phosphate."
  J. Am. Chem. Soc., 122, 4213-4214 (2000).

• D.W. Hughes, I.D. Spenser and J.T. Wrobel
  "An NMR study of the Lythraceae alkaloids."
  Magn. Res. Chem., 38, 707-718 (2000).

• D.E. Cane, S. Du, J.K. Robinson, Y. Hsiung and I.D. Spenser
  "Biosynthesis of Vitamin B₆: Enzymatic conversion of 1-deoxy-D-xylulose 5-phosphate to pyridoxol phosphate."
  J. Am. Chem. Soc., 121, 7722-7723 (1999).

• K. Himmeldirk, B.G. Sayer and I.D. Spenser
  "Comparative biogenetic anatomy of Vitamin B₁: A ¹³C NMR investigation of the biosynthesis of thiamin in Escherichia coli and Saccharomyces cerevisiae."
  J. Am. Chem. Soc., 120, 3581-3589 (1998).

• D.E. Cane, Y. Hsiung, J.A. Cornish, J.K. Robinson and I.D. Spenser
  "Biosynthesis of Vitamin B₆: The oxidation of 4-(phosphohydroxy)-L-thre onine by PdxA."
  J. Am. Chem. Soc., 120, 1936-1937 (1998).

---

Contact Information

Mailing Address: Dr I.D. Spenser Department of Chemistry McMaster University Hamilton, Ont., Canada L8S 4M1	Telephone: Voice (905) 525-9140, ext. 27791 or 23245 FAX   (905) 522-2509
Office: ABB-331	E-mail: spenser@mcmaster.ca

---

Chemistry Faculty
Department of Chemistry.

05nov2003; ids