- Fungal Dioxygenase AsqJ Is Promiscuous and Bimodal: Substrate-Directed Formation of Quinolones versus Quinazolinones
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Previous studies showed that the FeII/α-ketoglutarate dependent dioxygenase AsqJ induces a skeletal rearrangement in viridicatin biosynthesis in Aspergillus nidulans, generating a quinolone scaffold from benzo[1,4]diazepine-2,5-dione substrates. We report that AsqJ catalyzes an additional, entirely different reaction, simply by a change in substituent in the benzodiazepinedione substrate. This new mechanism is established by substrate screening, application of functional probes, and computational analysis. AsqJ excises H2CO from the heterocyclic ring structure of suitable benzo[1,4]diazepine-2,5-dione substrates to generate quinazolinones. This novel AsqJ catalysis pathway is governed by a single substituent within the complex substrate. This unique substrate-directed reactivity of AsqJ enables the targeted biocatalytic generation of either quinolones or quinazolinones, two alkaloid frameworks of exceptional biomedical relevance.
- Einsiedler, Manuel,Jamieson, Cooper S.,Maskeri, Mark A.,Houk, Kendall N.,Gulder, Tobias A. M.
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supporting information
p. 8297 - 8302
(2021/03/01)
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- EPHA4 CYCLIC PEPTIDE ANTAGONISTS AND METHODS OF USE THEREOF
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Disclosed herein are compounds and methods of use thereof for the modulation of EphA4 receptor activity. In an aspect, is provided a method of treating or preventing a disease or disorder mediated by EphA4, comprising administering to a subject in need thereof a therapeutically effective amount of a compound as described herein, including certain embodiments, or the structural Formula (I), (l-A), (II), (III), (IV), (IV-1), (V), (Vl-A), (Vl-B), (VII-1), (VII-2), (VIII-1), or (VIII-2), or an enantiomer, a mixture of enantiomers, a mixture of two or more diastereomers, or an isotopic variant thereof; or a pharmaceutically acceptable salt, solvate, or hydrate thereof.
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Paragraph 0632-0633; 0639; 0775-0777
(2019/11/19)
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- Total Synthesis and Biological Evaluation of Natural and Designed Tubulysins
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A streamlined total synthesis of N14-desacetoxytubulysin H (Tb1) based on a C-H activation strategy and a short total synthesis of pretubulysin D (PTb-D43) are described. Applications of the developed synthetic strategies and technologies to the synthesis of a series of tubulysin analogues (Tb2-Tb41 and PTb-D42) are also reported. Biological evaluation of the synthesized compounds against an array of cancer cells revealed a number of novel analogues (e.g., Tb14), some with exceptional potencies against certain cell lines [e.g., Tb32 with IC50 = 12 pM against MES SA (uterine sarcoma) cell line and 2 pM against HEK 293T (human embryonic kidney) cell line], and a set of valuable structure-activity relationships. The highly potent cytotoxic compounds discovered in this study are highly desirable as payloads for antibody-drug conjugates and other drug delivery systems for personalized targeted cancer chemotherapies.
- Nicolaou,Yin, Jun,Mandal, Debashis,Erande, Rohan D.,Klahn, Philipp,Jin, Michael,Aujay, Monette,Sandoval, Joseph,Gavrilyuk, Julia,Vourloumis, Dionisios
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supporting information
p. 1698 - 1708
(2016/02/20)
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