- New Multidentate Compounds of Ether-Ester Type
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A series of ether-esters containing multidentate components have been prepared from phenoxyacetic acid.The ligands were synthesized from the appropriate phenoxyacetic acid chloride and various alcohols.Four types of new compounds have been obtained. - Keywords: Acyclic crown compounds; Ester-ether crown compounds; Multidentate ligands; Phenoxyacetic acid ester
- Lin, Whei Oh,de Souza, Maria C. Bastos Viera,Altoe, Antonio P.,Alt, Helmut G.
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Read Online
- Polycarboxylated compounds and compositions containing same
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Methods of selectively modifying lignin, polycarboxylated products thereof, and methods of deriving aromatic compounds therefrom. The methods comprise electrochemically oxidizing lignin using stable nitroxyl radicals to selectively oxidize primary hydroxyls on β-O-4 phenylpropanoid units to corresponding carboxylic acids while leaving the secondary hydroxyls unchanged. The oxidation results in polycarboxylated lignin in the form of a polymeric β-hydroxy acid. The polymeric β-hydroxy acid has a high loading of carboxylic acid and can be isolated in acid form, deprotonated, and/or converted to a salt. The β-hydroxy acid, anion, or salt can also be subjected to acidolysis to generate various aromatic monomers or oligomers. The initial oxidation of lignin to the polycarboxylated form renders the lignin more susceptible to acidolysis and thereby enhances the yield of aromatic monomers and oligomers obtained through acidolysis.
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Page/Page column 22-23
(2021/06/09)
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- Modulation of DNA damage response by targeting ATM kinase using newly synthesized di-phenoxy acetamide (DPA) analogs to induce anti-neoplasia
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Background: Imbalance and instability in the structure of the DNA have become major characteristics of cancer. In response to DNA damage, DNA damage response (DDR) protein, ataxia telangiectasia mutated (ATM), plays a pivotal role in the modulation of regulatory regions responsible for inhibition of apoptosis, thereby neoplastic progression. Methods: A new series of DPA (7a–t) were synthesized, characterized. Anti-proliferative studies to identify the lead compound were carried out by LDH and MTT assay. Apoptosis/DNA damage was measured through FACS, Annexin-v staining, TUNEL and Comet assay. Elucidation of molecular mechanism through immunoblot and further validation of the drug effect through in vivo approaches. Results: Initial in vitro anti-proliferative screening of Compounds DPA (7a–t) against multiple cancer cell lines identified Compound DPA (7n) as a potent cytotoxic molecule with IC50 value of 4.3?μM. Down the line, in vitro and in vivo evaluation of Compound DPA (7n) inferred that it has apoptotic inducing potentiality. Further, evaluation of molecular mechanism inferred that Compound DPA (7n) effectively modulates ATM phosphorylation only, eventually altering downstream signalling pathways. Conclusions: Compound DPA (7n) emerged as a potent proapoptotic and anti-neoplastic agent by inhibiting ATM kinase activity both in vitro and in vivo. The conferring results ascertain that the drug could be developed as a new ATM kinase inhibitor with anti-cancer capacity. Graphic abstract: [Figure not available: see fulltext.]
- Al-Ostoot, Fares Hezam,Sherapura, Ankith,Malojirao, Vikas H.,Thirusangu, Prabhu,Al-Muhimeed, Tahani I.,Khanum, Shaukath Ara,Prabhakar
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p. 1344 - 1360
(2021/06/14)
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- Targeting HIF-1α by newly synthesized Indolephenoxyacetamide (IPA) analogs to induce anti-angiogenesis-mediated solid tumor suppression
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Background: Hypoxic microenvironment is a common feature of solid tumors, which leads to the promotion of cancer. The transcription factor, HIF-1α, expressed under hypoxic conditions stimulates tumor angiogenesis, favoring HIF-1α as a promising anticancer agent. On the other hand, synthetic Indolephenoxyacetamide derivatives are known for their pharmacological potentiality. With this background here, we have synthesized, characterized, and validated the new IPA (8a–n) analogs for anti-tumor activity. Methods: The new series of IPA (8a–n) were synthesized through a multi-step reaction sequence and characterized based on the different spectroscopic analysis FT-IR, 1H, 13C NMR, mass spectra, and elemental analyses. Cell-based screening of IPA (8a–n) was assessed by MTT assay. Anti-angiogenic efficacy of IPA (8k) validated through CAM, Rat corneal, tube formation and migration assay. The underlying molecular mechanism is validated through zymogram and IB studies. The in vivo anti-tumor activity was measured in the DLA solid tumor model. Results: Screening for anti-proliferative studies inferred, IPA (8k) is a lead molecule with an IC50 value of ?5?μM. Anti-angiogenic assays revealed the angiopreventive activity through inhibition of HIF-1α and modulation downstream regulatory genes, VEGF, MMPs, and P53. The results are confirmative in an in vivo solid tumor model. Conclusion: The IPA (8k) is a potent anti-proliferative molecule with anti-angiogenic activity and specifically targets HIF1α, thereby modulates its downstream regulatory genes both in vitro and in vivo. The study provides scope for new target-specific drug development against HIF-1α for the treatment of solid tumors. Graphic abstract: [Figure not available: see fulltext.].
- Al-Ostoot, Fares Hezam,Sherapura, Ankith,V, Vigneshwaran,Basappa, Giridhara,H.K, Vivek,B.T, Prabhakar,Khanum, Shaukath Ara
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p. 1328 - 1343
(2021/05/03)
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- Electrochemical Aminoxyl-Mediated Oxidation of Primary Alcohols in Lignin to Carboxylic Acids: Polymer Modification and Depolymerization
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An electrochemical process has been developed for chemoselective oxidation of primary alcohols in lignin to the corresponding carboxylic acids. The electrochemical oxidation reactions proceed under mildly basic conditions and employ 2,2,6,6-tetramethyl-1-piperidine N-oxyl (TEMPO) and 4-acetamidoO (ACT) as catalytic mediators. Lignin model compounds and related alcohols are used to conduct structure-reactivity studies that provide insights into the origin of the reaction selectivity. The method is applied to the oxidation of lignin extracted from poplar wood chips via a mild acidolysis method, and the reaction affords a novel polyelectrolyte material. Gel permeation chromatography data for the oxidized lignin shows that this material has a molecular weight and molecular weight distribution very similar to that of the extracted lignin, but notable differences are also evident. Base titration reveals a significant increase in the acid content, and the oxidized lignin has much higher water solubility relative to the extracted lignin. Treatment of the oxidized lignin under acidic conditions results in depolymerization of the material into characterized aromatic monomers in nearly 30 wt% yield.
- Rafiee, Mohammad,Alherech, Manar,Karlen, Steven D.,Stahl, Shannon S.
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supporting information
p. 15266 - 15276
(2019/10/19)
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- Design and Synthesis of Novel 4-Hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one Derivatives for Use as Herbicides and Evaluation of Their Mode of Action
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In order to develop a novel herbicide containing the β-triketone motif, a series of 4-hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one derivatives were designed and synthesized. The bioassay results showed that compound II15 had good pre-emergent herbicidal activity even at a dosage of 187.5 g ha-1. Moreover, compound II15 showed a broader spectrum of weed control when compared with a commercial herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), and displayed good crop safety to Triticum aestivum L. and Zea mays Linn. when applied at 375 g ha-1 under pre-emergence conditions, which indicated its great potential as a herbicide. More importantly, studying the molecular mode of action of compound II15 revealed that the novel triketone structure is a proherbicide of its corresponding phenoxyacetic acid auxin herbicide, which has a herbicidal mechanism similar to that of 2,4-D. The present work indicates that the 4-hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one motif may be a potential lead structure for further development of novel auxin-type herbicides.
- Lei, Kang,Li, Pan,Yang, Xue-Fang,Wang, Shi-Ben,Wang, Xue-Kun,Hua, Xue-Wen,Sun, Bin,Ji, Lu-Sha,Xu, Xiao-Hua
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p. 10489 - 10497
(2019/10/02)
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- Ketoreductase catalyzed stereoselective bioreduction of α-nitro ketones
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We report here the stereoselective bioreduction of α-nitro ketones catalyzed by ketoreductases (KREDs) with publicly known sequences. YGL039w and RasADH/SyADH were able to reduce 23 class I substrates (1-aryl-2-nitro-1-ethanone (1)) and ten class II substrates (1-aryloxy-3-nitro-2-propanone (4)) to furnish both enantiomers of the corresponding β-nitro alcohols, with good-to-excellent conversions (up to >99%) and enantioselectivities (up to >99% ee) being achieved in most cases. To the best of our knowledge, KRED-mediated reduction of class II α-nitro ketones (1-aryloxy-3-nitro-2-propanone (4)) is unprecedented. Select β-nitro alcohols, including the synthetic intermediates of bioactive molecules (R)-tembamide, (S)-tembamide, (S)-moprolol, (S)-toliprolol and (S)-propanolol, were stereoselectively synthesized in preparative scale with 42% to 90% isolated yields, showcasing the practical potential of our developed system in organic synthesis. Finally, the advantage of using KREDs with known sequence was demonstrated by whole-cell catalysis, in which β-nitro alcohol (R)-2k, the key synthetic intermediate of hypoglycemic natural product (R)-tembamide, was produced in a space-time yield of 178 g L?1 d?1 as well as 95% ee by employing the whole cells of a recombinant E. coli strain coexpressing RasADH and glucose dehydrogenase as the biocatalyst.
- Wang, Zexu,Wu, Xiaofan,Li, Zhining,Huang, Zedu,Chen, Fener
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supporting information
p. 3575 - 3580
(2019/04/14)
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- Iridium-catalysed primary alcohol oxidation and hydrogen shuttling for the depolymerisation of lignin
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Lignin is a potentially abundant renewable resource for the production of aromatic chemicals, however its selective depolymerisation is challenging. Here, we report a new catalytic system for the depolymerisation of lignin to novel, non-phenolic monoaromatic products based on the selective β-O-4 primary alcohol dehydrogenation with a Cp?Ir-bipyridonate catalyst complex under basic conditions. We show that this system is capable of promoting the depolymerisation of model compounds and isolated lignins via a sequence of selective primary alcohol dehydrogenation, retro-aldol (Cα-Cβ) bond cleavage and in situ stabilisation of the aldehyde products by transfer (de)hydrogenation to alcohols and carboxylic acids. This method was found to give good to excellent yields of cleavage products with both etherified and free-phenolic lignin model compounds and could be applied to real lignin to generate a range of novel non-phenolic monomers including diols and di-acids. We additionally show, by using the same catalyst in a convergent, one-pot procedure, that these products can be selectively channelled towards a single di-acid product, giving much simpler product mixtures as a result.
- Lancefield, Christopher S.,Teunissen, Lucas W.,Weckhuysen, Bert M.,Bruijnincx, Pieter C. A.
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supporting information
p. 3214 - 3221
(2018/07/31)
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- Isoflavone amide derivatives, their preparation method and medical use
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The invention belongs to the field of medicinal chemistry, and relates to derivatives of isoflavones amides, as well as a preparation method and medical application of derivatives, in particular to the derivatives of the isoflavones amides with the general formula of (I) shown as the specification, the preparation method and the medical application of the derivatives, particularly the application of the derivatives of the isoflavones amides serving as medicaments for preventing or treating hyperlipemia, adiposis or type-II diabetes.
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Paragraph 0077
(2017/08/31)
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- Discovery of benzofuran-3(2H)-one derivatives as novel DRAK2 inhibitors that protect islet β-cells from apoptosis
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Death-associated protein kinase-related apoptosis-inducing kinase-2 (DRAK2) is a serine/threonine kinase that plays a key role in a wide variety of cell death signaling pathways. Inhibition of DRAK2 was found to efficiently protect islet β-cells from apoptosis and hence DRAK2 inhibitors represent a promising therapeutic strategy for the treatment of diabetes. Only very few chemical entities targeting DRAK2 are currently known. We carried out a high throughput screening and identified compound 4 as a moderate DRAK2 inhibitor with an IC50value of 3.15?μM. Subsequent SAR studies of hit compound 4 led to the development of novel benzofuran-3(2H)-one series of DRAK2 inhibitors with improved potency and favorable selectivity profiles against 26 selected kinases. Importantly, most potent compounds 40 (IC50?=?0.33?μM) and 41 (IC50?=?0.25?μM) were found to protect islet β-cells from apoptosis in dose-dependent manners. These data support the notion that small molecule inhibitors of DRAK2 represents a promising strategy for the treatment of diabetes.
- Wang, Sheng,Xu, Lei,Lu, Yu-Ting,Liu, Yu-Fei,Han, Bing,Liu, Ting,Tang, Jie,Li, Jia,Wu, Jiangping,Li, Jing-Ya,Yu, Li-Fang,Yang, Fan
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p. 195 - 208
(2017/03/02)
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- Enantioselective Synthesis of Dilignol Model Compounds and Their Stereodiscrimination Study with a Dye-Decolorizing Peroxidase
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A four-step enantioselective approach was developed to synthesize anti (1R,2S)-1a and (1S,2R)-1b containing a β-O-4 linkage in good yields. A significant difference was observed for the apparent binding affinities of four stereospecific lignin model compounds with TcDyP by surface plasmon resonance, which was not translated into a significant difference in enzyme activities. The discrepancy may be attributed to the conformational change involving a loop widely present in DyPs upon H2O2 binding.
- Huang, Gaochao,Shrestha, Ruben,Jia, Kaimin,Geisbrecht, Brian V.,Li, Ping
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supporting information
p. 1820 - 1823
(2017/04/11)
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- Synthesis and biological evaluation of aryloxyacetamide derivatives as neuroprotective agents
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A series of new aryloxyacetamide derivatives 10a-s and 14a-m are designed and synthesized. Their protective activities against the glutamate-induced cell death were investigated in differentiated rat pheochromocytoma cells (PC12 cells). Most compounds exhibited neuroprotective effects, especially for 10m, 10r, 14b and 14c, which showed potential protection of PC12 cells at three doses (0.1, 1.0, 10 μM). MTT assay, Hoechst 33342/PI double staining, and high content screening (HCS) revealed that pretreatment of the cells with 10m, 10r, 14b and 14c has significantly decreased the extent of cell apoptosis in a dose-dependent manner. The results of western blot analysis demonstrated these compounds suppressed apoptosis of glutamate-induced PC12 cells via caspase-3 pathway. These compounds can be lead compounds for further discovery of neuroprotective agents for treating cerebral ischemic stroke. Basic structure-activity relationships are also presented.
- Zhong, Yan,Xu, Yi,Zhang, Ai-Xia,Li, Xiao-Feng,Xu, Zhao-Ying,Li, Ping,Wu, Bin
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supporting information
p. 2526 - 2530
(2016/07/07)
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- Formononetin derivatives and preparation methods and medical application thereof
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The invention relates to the field of pharmaceutical chemistry, and relates to formononetin derivatives and preparation methods and medical application thereof, in particular to formononetin derivatives with the general formula as shown in (I), preparation methods thereof, pharmaceutical compositions containing the compounds and medical application of the derivatives and the pharmaceutical compositions, particularly, application of the derivatives and the pharmaceutical compositions serving as drugs for preventing or treating hyperlipidaemia or obesity or type-II diabetes. Please see the formula in the description.
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Paragraph 0069; 0070; 0071; 0081; 0082; 0083
(2017/04/29)
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- Chemoselective catalytic oxidation of 1,2-diols to α-hydroxy acids controlled by TEMPO-ClO2 charge-transfer complex
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Chemoselective catalytic oxidation from 1,2-diols to α-hydroxy acids in a cat. TEMPO/cat. NaOCl/NaClO2 system has been achieved. The use of a two-phase condition consisting of hydrophobic toluene and water suppresses the concomitant oxidative cleavage. A study of the mechanism suggests that the observed selectivity is derived from the precise solubility control of diols and hydroxy acids as well as the active species of TEMPO. Although the oxoammonium species TEMPO+Cl- is hydrophilic, the active species dissolves into the organic layer by the formation of the charge-transfer (CT) complex TEMPO-ClO2 under the reaction conditions.
- Furukawa, Keisuke,Shibuya, Masatoshi,Yamamoto, Yoshihiko
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supporting information
p. 2282 - 2285
(2015/05/13)
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- Synthesis and biological evaluation of isoflavone amide derivatives with antihyperlipidemic and preadipocyte antiproliferative activities
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A series of isoflavone amides were designed with isoflavone in place of the scaffold of 2-arylbenzoxazole as cholesterol ester transfer protein (CETP) inhibitors. Twelve new compounds were synthesized, and their inhibitory activities of CETP and preadipocyte proliferation were assayed. The hypolipidemic potency of the most effective compound HY-2c was further tested in vivo by hamster. The results indicate that HY-2c exhibited favorable antihyperlipidemic and preadipocyte antiproliferative activities.
- Wang, Wenbin,He, Yi,Xu, Pei,You, Qidong,Xiao, Hong,Xiang, Hua
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p. 4428 - 4433
(2015/08/03)
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- Finding new elicitors that induce resistance in rice to the white-backed planthopper Sogatella furcifera
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Herein we report a new way to identify chemical elicitors that induce resistance in rice to herbivores. Using this method, by quantifying the induction of chemicals for GUS activity in a specific screening system that we established previously, 5 candidate elicitors were selected from the 29 designed and synthesized phenoxyalkanoic acid derivatives. Bioassays confirmed that these candidate elicitors could induce plant defense and then repel feeding of white-backed planthopper Sogatella furcifera.
- He, Xingrui,Yu, Zhaonan,Jiang, Shaojie,Zhang, Peizhi,Shang, Zhicai,Lou, Yonggen,Wu, Jun
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supporting information
p. 5601 - 5603
(2015/11/17)
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- Catalyst-free photoredox addition-cyclisations: Exploitation of natural synergy between aryl acetic acids and maleimide
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Suitably functionalised carboxylic acids undergo a previously unknown photoredox reaction when irradiated with UVA in the presence of maleimide. Maleimide was found to synergistically act as a radical generating photoxidant and as a radical acceptor, negating the need for an extrinsic photoredox catalyst. Modest to excellent yields of the product chromenopyrroledione, thiochromenopyrroledione and pyrroloquinolinedione derivatives were obtained in thirteen preparative photolyses. In situ NMR spectroscopy was used to study each reaction. Reactant decay and product build-up were monitored, enabling reaction profiles to be plotted. A plausible mechanism, whereby photo-excited maleimide acts as an oxidant to generate a radical ion pair, has been postulated and is supported by UV/Vis. spectroscopy and DFT computations. The radical-cation reactive intermediates were also characterised in solution by EPR spectroscopy. UVA photolyses of aryloxy-, arylthio- and arylamino-acetic acids with maleimide yield oxa-, thia- and aza-tricyclo pyrroledione derivatives in the absence of a photoredox catalyst (see scheme). An intriguing mechanism has been proposed and has been supported and supplemented by NMR monitoring experiments, DFT computations and UV/Vis and EPR spectroscopy.
- Manley, David W.,Mills, Andrew,O'Rourke, Christopher,Slawin, Alexandra M. Z.,Walton, John C.
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supporting information
p. 5492 - 5500
(2014/05/20)
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- Synthesis and structural characterization of 2-benzylidenebenzofuran-3-(2 H)-ones
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Novel aurone derivatives e.g. 2-(2-(3-methylbut-2-enyloxy)benzylidene) benzofuran-3(2H)-one (3a), 2-(2-(allyloxy)benzylidene)-7-methoxybenzofuran-3(2H) -one (3b), and 2-(5-bromo-2-(3-methylbut-2-enyloxy)benzylidene)-6- hydroxybenzofuran-3(2H)-one (3c) were synthesized. All these compounds were characterized by IR, 1H and 13C NMR, and Mass spectroscopy. Finally, the crystal structures were solved by single crystal X-ray diffraction data and the structures were analyzed in terms of supramolecular interactions. [Supplementary materials are available for this article. Go to the publisher's online edition of Molecular Crystals and Liquid Crystals for the following free supplemental resource(s): supplemental figures 1-12; Spectral data (IR, NMR, MS, and HRMS) of the compounds 3a, 3b and 3c are available in the supporting information in.pdf format. Crystallographic information files (.cif) of compounds 3a, 3b, and 3c are available in the electronic format.]
- Rambabu,Srinivas,Manjulatha, Khanapur,Basavoju, Srinivas,Basaveswara Rao,Pal, Manojit
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- Ethylenediamine diacetate (EDDA) mediated synthesis of aurones under ultrasound: Their evaluation as inhibitors of SIRT1
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An improved synthesis of functionalized aurones has been accomplished via the reaction of benzofuran-3(2H)-one with a range of benzaldehydes in the presence of a mild base EDDA under ultrasound. A number of aurones were synthesized (within 5-30 min) and the molecular structure of a representative compound determined by single crystal X-ray diffraction study confirmed Z-geometry of the C-C double bond present within the molecule. Some of the compounds synthesized have shown SIRT1 inhibiting as well as anti proliferative properties against two cancer cell lines in vitro. Compound 3a [(Z)-2-(5-bromo-2-hydroxybenzylidene) benzofuran-3(2H)-one] was identified as a potent inhibitor of SIRT1 (IC50 = 1 μM) which showed a dose dependent increase in the acetylation of p53 resulting in induction of apoptosis.
- Manjulatha, Khanapur,Srinivas,Mulakayala, Naveen,Rambabu,Prabhakar,Arunasree, Kalle M.,Alvala, Mallika,Basaveswara Rao,Pal, Manojit
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p. 6160 - 6165
(2012/10/30)
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- Preparation of diastereomerically pure dilignol model compounds
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A gram-scale synthetic access to diastereomerically pure dilignol β-O-4 type model compounds, which represent valuable candidates for studies of lignin cleavage and valorization, is described. Following a straightforward procedure both diastereoisomers of 1,3-dilignols can be prepared. In the key-step, tert-butyl aryloxy esters are used as enolate precursors for additions on aldehydes. After separation, the resulting erythro and threo β-hydroxy esters are independently reduced to afford the target compounds in high yields.
- Buendia, Julien,Mottweiler, Jakob,Bolm, Carsten
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supporting information; experimental part
p. 13877 - 13882
(2012/01/15)
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- Aryloxyacetic esters structurally related to α-Asarone as potential antifungal agents
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A series of aryloxyacetic ester analogues 8-13 was synthesized based on the potential pharmacophores of the antifungal agents α-Asarone (1) and 2-5. Their antifungal activity was tested in vitro for their growth inhibitory activities against pathogenic fungi. The in vitro antifungal evaluation of these alkyl and aryl esters shows that derivatives 10 displayed the highest antifungal and fungicidal activities against Cryptococcus neoformans and C. gattii. These results support the idea that the phenoxyacetic frame is a potent pharmacophore for the design of potential antifungal drugs. Graphical Abstract: [Figure not available: see fulltext.]
- Jimenez, Fabiola,Cruz, Maria Del Carmen,Zuniga, Clara,Martinez, Maria A.,Chamorro, German,Diaz, Francisco,Tamariz, Joaquin
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experimental part
p. 33 - 57
(2010/10/20)
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- Synthesis and biological evaluation of some novel 2-mercaptobenzothiazoles carrying 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole moieties
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Several 2-mercaptobenzothiazole derivatives containing 1,3,4-oxadiazoles, 1,2,4-triazoles and 1,3,4-thiadiazoles at the second position were synthesized. Some of these synthesized compounds were evaluated for their in vivo analgesic, anti-inflammatory, acute toxicity and ulcerogenic actions. Some of the tested compounds showed significant analgesic and anti-inflammatory activities. Two of the compounds showed significant gastrointestinal protection compared to the standard drug diclofenac sodium. The compounds were also tested for their in vitro antimicrobial activity with most displaying selective activity against the Gram-negative bacteria Pseudomonas aeruginosa. In the present investigation the tested compounds did not possess antifungal activity.
- Azam, M. Afzal,Suresh, Bhojraj,Kalsi, Sandip S.,Antony, A. Shinesh
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scheme or table
p. 114 - 122
(2011/06/09)
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- Design, synthesis and in vitro antibacterial/antifungal evaluation of novel 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7(1-piperazinyl)quinoline-3-carboxylic acid derivatives
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A series of 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7(1-piperazinyl)quinoline-3-carboxylic acid (norfloxacin) derivatives were prepared according to the principle of combinating bioactive substructures and tested for their activities against five plant pathogenic bacteria and three fungi in vitro. The preliminary bioassays indicated that almost all synthesized target compounds retained the antibacterial activities of norfloxacin and had some antifungal activities as carboxylic acid amide compounds. The activities of compounds 1 and 22 against Xanthomonas oryzae were better than norfloxacin and all tested compounds had better antibacterial activities as compared to the agricultural streptomycin sulfate (a commercial bactericide) against X. oryzae, Xanthomonas axonopodis and Erwinia aroideae. Additionally, compounds 2 and 20 displayed good antifungal activities against Rhizoctonia solani and their inhibition of growth reached 83% and 94% respectively at the concentration of 200 mg/L.
- Yu, Zhiyi,Shi, Guanying,Sun, Qiu,Jin, Hong,Teng, Yun,Tao, Ke,Zhou, Guoping,Liu, Wei,Wen, Fang,Hou, Taiping
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scheme or table
p. 4726 - 4733
(2010/01/06)
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- Antimalarial activity enhancement in hydroxymethylcarbonyl (HMC) isostere-based dipeptidomimetics targeting malarial aspartic protease plasmepsin
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Plasmepsin (Plm) is a potential target for new antimalarial drugs, but most reported Plm inhibitors have relatively low antimalarial activities. We synthesized a series of dipeptide-type HIV protease inhibitors, which contain an allophenylnorstatine-dimethylthioproline scaffold to exhibit potent inhibitory activities against Plm II. Their activities against Plasmodium falciparum in the infected erythrocyte assay were largely different from those against the target enzyme. To improve the antimalarial activity of peptidomimetic Plm inhibitors, we attached substituents on a structure of the highly potent Plm inhibitor KNI-10006. Among the derivatives, we identified alkylamino compounds such as 44 (KNI-10283) and 47 (KNI-10538) with more than 15-fold enhanced antimalarial activity, to the sub-micromolar level, maintaining their potent Plm II inhibitory activity and low cytotoxicity. These results suggest that auxiliary substituents on a specific basic group contribute to deliver the inhibitors to the target Plm.
- Hidaka, Koushi,Kimura, Tooru,Ruben, Adam J.,Uemura, Tsuyoshi,Kamiya, Mami,Kiso, Aiko,Okamoto, Tetsuya,Tsuchiya, Yumi,Hayashi, Yoshio,Freire, Ernesto,Kiso, Yoshiaki
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scheme or table
p. 10049 - 10060
(2009/04/07)
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- THIADIAZOLE DERIVATIVES, INHIBITORS OF STEAROYL-COA DESATURASE
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The present invention relates to substituted thiadiazole compounds of the formula (I) and pharmaceutically acceptable salts thereof, to pharmaceutical compositions containing them and their use in medicine. In particular, the invention relates to compounds for modulating SCD activity.
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Page/Page column 46
(2008/12/07)
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- Mild and reliable cleavage sequence for phenoxy acetates
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A novel combination of reliable transformations like ester saponification and subsequent Curtius-rearrangement employing mild reaction conditions, offers the first synthetically interesting strategy for the removal of methoxycarbonylmethyl groups from phenolic oxygens. This methodology gives also access to labile iodosubstituted phenols. A novel combination of reliable transformations like ester saponification and subsequent Curtius-rearrangement employing mild reaction conditions, offers the first synthetically interesting strategy for the removal of methoxycarbonylmethyl groups from phenolic oxygens. This methodology gives also access to labile iodosubstituted phenols.
- Mirk, Daniela,Waldvogel, Siegfried R.
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p. 7911 - 7914
(2007/10/03)
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- Electrochemically-induced spirolactonization of α-(methoxyphenoxy)alkanoic acids into quinone ketals
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Anodic oxidation of two series of α-(2)- and α-(4-methoxyphenoxy)alkanoic acids were studied both at the analytical and preparative scales in order to delineate mechanistic aspects of electrochemically induced spirolactonization and to develop synthetically useful orthoquinone bis- and monoketals. Although α-monomethylated carboxylic acids and acetic acid derivatives do not undergo any spiroannulation, α-dimethylated carboxylic acids furnished spirolactones in high yields. A gem-dimethyl effect is invoked to explain these differences in cyclization capacity. Electrooxidation conditions can be selected to furnish either quinone spirolactone bis- or monoketals. Chemoselective monohydrolysis of bisketals can also be accomplished in a stepwise fashion to furnish the corresponding spirolactone monoketals, but the ortho compound unfortunately dimerized in situ via a Diels-Alder process. An ECEC pathway is proposed to rationalize the observed spirolactonizations on the basis of cyclic voltammetry analyses.
- Deffieux, Denis,Fabre, Isabelle,Courseille, Christian,Quideau, Stephane
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p. 4458 - 4465
(2007/10/03)
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- Cyclotriveratrylene models for proteins: 3:1 subsite differentiation and modulation of the redox potential
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The potential of cyclotriveratrylene (ctv) (2,3,7,8,12,13-hexamethoxy-10,15-dihydro-5H-tribenzocyclo-nonene) trithiols as ligands that can easily be functionalised and show subsite differentiation in their complexes with clusters has been explored.The cluster complexes of tris(2-sulfanylethoxy)- and tris(3-sulfanyl-methylbenzyloxy)-functionalised ctvs have been studied by core-extrusion experiments, spectroscopy and electrochemical techniques.With 2- as starting material a cluster complex was obtained in which the unique Fe and its co-ordinating Cl was turned into the cavity and show no reactivity.Starting with the more bulky t)4>2- the unique iron points outwards and is susceptible to substitution reactions.The effects of hydrogen bonding and electron density on the redox potential of the cluster complex have been investigated.The redox potential becomes more negative when the length of the spacer between the ctv and cluster core is increased, which is explained by the longer distance between the cluster and the electron-withdrawing phenoxy moiety of the ctv.The synthesis of ctv derivatives with one thiol and one alcohol functionality per phenyl unit, and comparison with corresponding derivatives where hydrogen bonding is not possible, showed that no significant differences were found.The effects of a substituent in an aromatic amide group that could hydrogen bond to the co-ordinated thiol were investigated.A weak effect, in the direction expected, was found upon substitution of methyl for H.
- Strijdonck, Gino P. F. van,Haare, John A. E. H. van,Hoenen, Paulus J.M.,Schoor, Roger C. G. M. van den,Feiters, Martinus C.,et al.
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p. 449 - 462
(2007/10/03)
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- Stereoselective Syntheses of Lignin Model Compounds of the β-0-4 and β-1 Types
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The preparation of erythro forms of lignin model compounds of the β-0-4 type by hydroboration of α-aryloxycinnamic acids, using a borate dimethyl sulfide complex as a reagent, has been studied.The erythro form of 1-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)-1,3-propanediol was obtained in a yeild of about 50percent.Acid-catalyzed rearangements of chalcone oxides result in the formation of α-formyldesoxibenzoins which give 1,2-diaryl-1,3-propanediols on borohydride reduction.The synthesis of the erythro forms of 1,2-bis(4-hydroxy-3-methoxyphenyl)-1,3-propanediol and 1,2-bis(4-hydroxy-3,5-dimethoxyphenyl)-1,3-propanediol by this reaction route is discribed; 1,2-diaryl-1,3-propanediols represent lignin model compounds for the β-1 type of structure.
- Ahvonen, Toivo,Brunow, Goesta,Kristersson, Per,Lundquist, Knut
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p. 845 - 850
(2007/10/02)
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