1. Wood Chemistry and Biochemistry, Department of Forest Products, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061.
2. Philip Morris USA Research Center, Richmond, VA 23261.
3. Department of Chemistry, McGill University, Montreal, PQ, Canada H3A 2A7.
4. Department of Botany, University of British Columbia, Vancouver, BC, Canada V6T 1Y6.