Design, synthesis, and biological evaluation of novel 4-substituted 1-methyl-1,2,3,6-tetrahydropyridine analogs of MPTP
摘要:
The exceptionally good MAO-B substrate properties of several 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) derivatives have prompted studies to evaluate the corresponding properties of tetrahydropyridines bearing heteroatom-linked groups at C-4. The 1-methyl-4-phenoxy-1,2,3,6-tetrahydropyridine analog proved to be an excellent MAO-B substrate. Unlike analogs bearing hydrocarbon substituents at C-4, the resulting dihydropyridinium metabolite did not undergo further oxidation to the pyridinium compound but rather underwent hydrolytic cleavage. This observation has led to studies designed to explore the possibility of developing novel, nontoxic derivatives of MPTP bearing potential pharmacologically active leaving groups at C-4. In this paper we report the results of synthetic and metabolic studies on a series of tetrahydropyridine analogs of MPTP with oxygen, sulfur, and carbamoyloxy derivatives on C-4 which serve as model compounds to evaluate the scope of this prodrug concept.
Beyond the Cyanine Limit: Peierls Distortion and Symmetry Collapse in a Polymethine Dye
作者:Laren M. Tolbert、Xiaodong Zhao
DOI:10.1021/ja9626953
日期:1997.4.1
Theory predicts that cyanine dyes and related linear systems undergo symmetry collapse and bond localization at long chain lengths. Beyond this ''cyanine limit'', the properties of these systems do not extrapolate from their shorter counterparts. To test this prediction, dipyridocyanines have been synthesized and shown to undergo such symmetry collapse with chain lengths as short as 13.