Design of Inhibitors of Scytalone Dehydratase: Probing Interactions with an Asparagine Carboxamide
摘要:
Among the active-site residues of scytalone dehydratase, the side-chain carboxamide of asparagine 131 has the greatest potential for strong electrostatic interactions. Structure-based inhibitor design aimed at enhancing interactions with this residue led to the synthesis of a series of highly potent inhibitors that have a five- or six-membered ring containing a carbonyl functionality for hydrogen bonding. To achieve a good orientation for hydrogen bonding, the inhibitors incorporate a phenyl substituent that displaces a phenylalanine residue away from the five- or six-membered rings. Without the phenyl substituent, inhibitor binding potency is diminished by three orders of magnitude. Larger K, values of a site-directed mutant (Asn131Ala) of scytalone dehydratase in comparison to those of wild-type enzyme validate the design concept. The most potent inhibitor (K-i = 15 pM) contains a tetrahydrothiophenone that can form a single hydrogen bond with the asparagine carboxamide. Inhibitors with a butyrolactam that can form two hydrogen bonds with the asparagine carboxamide demonstrate excellent in vivo fungicidal activity. (C) 2002 Elsevier Science Ltd. All rights reserved.
衍生自去甲麻黄碱和其他手性(对映体纯的)氨基醇的手性(对映体纯的)硫代磷酰胺酸氢盐和氨基磷酸氢盐及其次膦酰胺类似物催化二烷基嗪与醛的对映选择性加成。四异丙氧基钛的存在增加了对映选择性,为对映体富集的仲醇提供了高达98%的ee。硫代磷酰胺化物和硫代膦酰胺的对映选择性高于氧类似物的对映选择性。在没有Ti(O i Pr)4的情况下,没有羟基的氨基磷酸酯和硫代磷酰胺酸酯也催化将二烷基锌加成到醛上。
Design of scytalone dehydratase inhibitors as rice blast fungicides: Derivatives of norephedrine
作者:Gregory S. Basarab、Douglas B. Jordan、Troy C. Gehret、Rand S. Schwartz、Zdzislaw Wawrzak
DOI:10.1016/s0960-894x(99)00247-4
日期:1999.6
Five X-ray crystalstructures of scytalone dehydratase complexed with different inhibitors have delineated conformationally flexible regions of the binding pocket. This information was used for the design and synthesis of a norephedrine-derived cyanoacetamide class of inhibitors leading to potent fungicides.