- Methoxycamalexins and related compounds: Syntheses, antifungal activity and inhibition of brassinin oxidase
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The phytoalexin camalexin is a competitive inhibitor of brassinin oxidase, an enzyme that detoxifies the phytoalexin brassinin and is produced by an economically important plant pathogen. For this reason, the camalexin scaffold has guided the design of inhibitors of brassinin detoxification. To further understand the structure–activity relationships of camalexin related compounds, the syntheses of monomethoxy and dimethoxycamalexins were undertaken. Four monomethoxy camalexins together with 4,6-dimethoxy and 5,7-dimethoxy camalexins were prepared from the corresponding methoxyindoles using the Ayer's method. The dimethoxy derivatives were prepared from the corresponding dimethoxyindole-3-thiocarboxamides using the Hantzsch reaction; however, this method did not work for the syntheses of 4,6-dimethoxy and 5,7-dimethoxycamalexins due to the lower reactivities of the corresponding indole-3-thiocarboxamides. The antifungal activity and brassinin oxidase inhibitory activity of all methoxycamalexins and ten camalexin related compounds were investigated. Among the 20 compounds evaluated, monomethoxycamalexins were stronger antifungals than the dimethoxy derivatives. However, remarkably, 5,6-dimethoxycamalexin, 6,7-dimethoxycamalexin and 5-methoxycamalexin displayed the strongest inhibitory activity against brassinin oxidase, while 4,5-dimethoxycamalexin displayed no inhibitory effect. Altogether the structure–activity relationships of camalexin related compounds suggest that the targets for fungal growth inhibition and brassinin oxidase inhibition are unrelated and emphasize that brassinin oxidase inhibitors do not need to be antifungal.
- Pedras, M. Soledade C.,Abdoli, Abbas
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p. 4461 - 4469
(2018/08/06)
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- 1,2,3-Thiadiazole substituted pyrazolones as potent KDR/VEGFR-2 kinase inhibitors
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KDR kinase inhibition is considered to play an important role in regulating angiogenesis, which is vital for the survival and proliferation of tumor cells. Recently we disclosed a structure-based kinase inhibitor design strategy which led to the identification of a new class of VEGFR-2/KDR kinase inhibitors bearing heterocyclic substituted pyrazolones as the core template. Instability in a rat S9 preparation and poor iv PK profiles for most of these inhibitors necessitated exploration of new pyrazolones to identify new analogs with improved metabolic stability. Optimization of the heterocyclic moiety led to the identification of the thiadiazole series of pyrazolones (D) as potent VEGFR-2/KDR kinase inhibitors. SAR modifications, kinase selectivity profiling, and structural elements for improved PK properties were explored. Oral bioavailability up to 29% was achieved in the rat. Modeling results based on the Glide XP docking approach supported our postulation regarding the interaction of the lactam segment of the pyrazolones with the hinge region of the KDR kinase.
- Tripathy, Rabindranath,Ghose, Arup,Singh, Jasbir,Bacon, Edward R.,Angeles, Thelma S.,Yang, Shi X.,Albom, Mark S.,Aimone, Lisa D.,Herman, Joseph L.,Mallamo, John P.
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p. 1793 - 1798
(2007/10/03)
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- Synthesis and antitumor characterization of pyrazolic analogues of the marine pyrroloquinoline alkaloids: Wakayin and tsitsikammamines
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A series of aza analogues of the marine alkaloids wakayin and tsitsikammamines A and B have been synthesized. The strategy used was based on [3 + 2] cycloaddition reactions involving 3-ethylamine-indole-4,7-dione and different diazo reagents. All the comp
- Legentil, Laurent,Benel, Laurent,Bertrand, Viviane,Lesur, Brigitte,Delfourne, Evelyne
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p. 2979 - 2988
(2007/10/03)
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- Synthesis of novel pentacyclic pyrrolothiazolobenzoquinolinones, analogs of natural marine alkaloids
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Multistep synthesis (12 steps) of new pentacyclic compounds, which are structurally very close to natural marine alkaloids, was performed via a Diels-Alder reaction between 4-methylene-5-(bromomethylene)-4,5-dihydrothiazole and a protected dioxotryptamine
- Bénéteau, Valérie,Besson, Thierry
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p. 2673 - 2676
(2007/10/03)
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- Propenone derivatives
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The present invention relates to propenone derivatives represented by the following formula (I): STR1 wherein R1 represents hydrogen, substituted or unsubstituted lower alkyl, substituted or unsubstituted aryl, or YR5 (wherein Y represents S or O; and R5 represents substituted or unsubstituted lower alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, or a substituted or unsubstituted cyclic ether residue); R2 and R3 independently represent hydrogen, lower alkyl, or substituted or unsubstituted aralkyl, or alternatively R2 and R3 are combined to form substituted or unsubstituted methylene or ethylene; R4 represents hydrogen, hydroxy, lower alkyl, substituted or unsubstituted aralkyl, lower alkoxy, substituted or unsubstituted aralkyloxy, or halogen; and X represents substituted or unsubstituted indolyl; or pharmaceutically acceptable salts thereof.
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