1. Contribution from the Department of Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido 1-1, Gifu 501-11, Japan, Department of Chemistry and Molecular Chirality Research Unit, Nagoya University, Chikusa, Nagoya 464-01, Japan, and Section of Molecular Therapeutics, Department of Experimental Pediatrics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030