Kurita K, Nishibori T, Harata M. Synthesis and asymmetric reducing performance of chitin/dihydronicotinamide conjugates having glycine or L-leucine spacer arms.
Biomacromolecules 2002;
3:705-9. [PMID:
12099814 DOI:
10.1021/bm025509w]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Chitin/dihydronicotinamide conjugates having glycine or L-leucine spacer arms have been prepared and evaluated as asymmetric reducing agents. N-Nicotinoylglycine and N-nicotinoyl-L-leucine were synthesized and coupled with the amino group of water-soluble 50%-deacetylated chitin. The remaining free amino groups were acetylated, and the nicotinamide groups were transformed into dihydronicotinamide moieties by quaternization followed by reduction. The resulting L-leucine-containing conjugate reduced ethyl benzoylformate efficiently with high chemical yield and asymmetric selectivity, whereas the glycine-containing conjugate gave only poor results. The recovered L-leucine-containing conjugate was reduced to regenerate the dihydronicotinamide structure and could be used again. The L-leucine residue has thus proved suitable as a spacer arm to achieve a high reducing performance.
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