14199-15-6Relevant articles and documents
Fe(III)-Catalyzed Aromatic Hydroxylation with H2O2 in the Presence of a Variety of Electron-Transfer Agents
Tamagaki, Seizo,Sasaki, Masaaki,Tagaki, Waichiro
, p. 153 - 158 (1989)
Electron-transfer agents such as N,N,N',N'-tetramethylphenylenediamine (TMPD), ferrocenes, and phenothiazines have been found to mediate the hydroxylation of benzene with H2O2 in the presence of Fe3+.Of these, TMPD catalyst is the most effective to provide phenol in 80percent or better yield based on added H2O2 under the optimized conditions.A general mechanism, involving the rate-determining reduction of Fe3+ to Fe2+ with such mediators, is suggested.
An iGlu Receptor Antagonist and Its Simultaneous Use with an Anticancer Drug for Cancer Therapy
Tan, Si Yu,Ang, Chung Yen,Luo, Zhong,Li, Peizhou,Nguyen, Kim Truc,Zhao, Yanli
, p. 6123 - 6131 (2015)
Glutamate receptor antagonists have been known to play a crucial role in the treatment of many neuronal diseases. Recently, these antagonists have also shown therapeutic effects in the treatment of cancer. In this study, an ionotropic glutamate (iGlu) receptor antagonist, 4-hydroxyphenylacetyl spermine (L1), was used concurrently with a common anticancer drug, doxorubicin (Dox), for simultaneous cancer therapy. Mesoporous silica nanoparticles (MSNPs) were employed as the delivery vehicle for both L1 and Dox by conjugating the iGlu receptor antagonist on the surface and encapsulating Dox within the mesopores. Dox was then trapped within the mesopores by functionalizing a redox-cleavable capping group on the MSNP surface, and it could be released upon exposure to the reductive glutathione. In vitro studies on B16F10 and NIH3T3 cell lines revealed that the iGlu receptor antagonist L1 exhibited therapeutic as well as targeting effects. In addition, the simultaneous use of therapeutic L1 and Dox proved to be synergistic in the treatment of cancer. The present work demonstrated the feasibility of employing a delivery system to deliver both neuroprotective drug and anticancer drug for efficient anticancer treatment.
Synthesis and characterization of a novel Mn(III)-(γ-diketone) complex with catalytic and antifungal activity
Dubey, Priti,Yadava, Sudha
, p. 3392 - 3404 (2018)
A novel Mn(III) complex with γ-diketone having general formula [Mn(hdo)3], where hdo = hexane-2,5-dione ligand, has been synthesized and characterized using UV–vis, FT-IR, ESI-mass and EPR spectra, elemental analysis, powder X-ray diffraction, SEM, and magnetic susceptibility measurements. The X-ray diffraction studies reveal that it has monoclinic lattice system with C2/C space group and the unit cell dimensions are a = 9.92245 ?, b = 10.50696 ?, and c = 9.80835 ?. The particle size of this complex has been found to be 32.1 nm. The complex was evaluated for its antifungal activity against Aspergillus flavus, Aspergillus niger, and Aspergillus terreus fungal species. The results indicate that the minimum inhibitory concentration of the synthesized complex was 8 ppm for A. niger while for A. flavus and A. terreus it was 6 ppm. β-Diketone Mn(III) complexes inhibit the fungal growth only partially. This communication is the first report of transformation of a keto-group to an ester group catalyzed by a metal complex.
Mechanism of photosolvolytic rearrangement of p-hydroxyphenacyl esters: Evidence for excited-state intramolecular proton transfer as the primary photochemical step
Zhang, Kai,Corrie, John E. T.,Munasinghe, V. Ranjit N.,Wan, Peter
, p. 5625 - 5632 (1999)
The photosolvolytic rearrangement of a variety of p-hydroxyphenacyl esters and related compounds 7-16 has been studied in solutions with up to 50% aqueous content, using product studies, triplet quenchers, and nanosecond laser flash photolysis. The p-hydroxyphenacyl moiety has recently been proposed as a new and efficient photoactivated protecting group in aqueous solution. Practical applications have been demonstrated, but much less is known about the mechanism of photoreaction. Our data support a novel mechanism in which the primary photochemical step from the singlet excited state is formal intramolecular proton transfer from the phenolic proton to the carbonyl oxygen of the distal ketone, mediated by solvent water, to generate the corresponding p-quinone methide phototautomer. This reactive intermediate (most likely in its excited state) subsequently expels the carboxylic acid with concerted rearrangement to a spiroketone intermediate, which subsequently leads to the final observed product, p- hydroxyphenylacetic acid. An alternative mechanism is deprotonation of the phenolic proton, loss of the carboxylate, and rearrangement to the spiroketone, all in one concerted primary photochemical step from S1.
Identification and Profiling of a Novel Diazaspiro[3.4]octane Chemical Series Active against Multiple Stages of the Human Malaria Parasite Plasmodium falciparum and Optimization Efforts
Le Manach, Claire,Dam, Jean,Woodland, John G.,Kaur, Gurminder,Khonde, Lutete P.,Brunschwig, Christel,Njoroge, Mathew,Wicht, Kathryn J.,Horatscheck, André,Paquet, Tanya,Boyle, Grant A.,Gibhard, Liezl,Taylor, Dale,Lawrence, Nina,Yeo, Tomas,Mok, Sachel,Eastman, Richard T.,Dorjsuren, Dorjbal,Talley, Daniel C.,Guo, Hui,Simeonov, Anton,Reader, Janette,Van Der Watt, Mari?tte,Erlank, Erica,Venter, Nelius,Zawada, Jacek W.,Aswat, Ayesha,Nardini, Luisa,Coetzer, Theresa L.,Lauterbach, Sonja B.,Bezuidenhout, Belinda C.,Theron, Anjo,Mancama, Dalu,Koekemoer, Lizette L.,Birkholtz, Lyn-Marie,Wittlin, Sergio,Delves, Michael,Ottilie, Sabine,Winzeler, Elizabeth A.,Smith, Dennis,Fidock, David A.,Street, Leslie J.,Basarab, Gregory S.,Duffy, James,Chibale, Kelly
supporting information, p. 2291 - 2309 (2021/03/01)
A novel diazaspiro[3.4]octane series was identified from a Plasmodium falciparum whole-cell high-throughput screening campaign. Hits displayed activity against multiple stages of the parasite lifecycle, which together with a novel sp3-rich scaffold provided an attractive starting point for a hit-to-lead medicinal chemistry optimization and biological profiling program. Structure-activity-relationship studies led to the identification of compounds that showed low nanomolar asexual blood-stage activity (50 nM) together with strong gametocyte sterilizing properties that translated to transmission-blocking activity in the standard membrane feeding assay. Mechanistic studies through resistance selection with one of the analogues followed by whole-genome sequencing implicated the P. falciparum cyclic amine resistance locus in the mode of resistance.
Discovery of novel 2,3,5-trisubstituted pyridine analogs as potent inhibitors of IL-1β via modulation of the p38 MAPK signaling pathway
Campos, Pedro M.,Carrasco, Esther,Gomez-Gutierrez, Patricia,Messeguer, Angel,Perez, Juan J.,Vega, Miguel
, (2021/07/28)
Interleukin-1β is a central mediator of innate immune responses and inflammation. It plays a key role in a wide variety of pathologies, ranging from autoinflammatory diseases to metabolic syndrome and malignant tumors. It is well established that its inhibition results in a rapid and sustained reduction in disease severity, underlining the importance of having a repertoire of drugs of this class. At present, there are only three interleukin-1β blockers approved in the clinic. All of them are biologics, requiring parenteral administration and resulting in expensive treatments. In an exercise to identify small molecule allosteric inhibitors of MAP kinases, we discovered a series of compounds that block IL-1β release produced as a consequence of a stimulus involved in triggering an inflammatory response. The present study reports the hit-to-lead optimization process that permitted the identification of the compound 13b (AIK3-305) an orally available, potent and selective inhibitor of IL-1β. Furthermore, the study also reports the results of an in vivo efficacy study of 13b in a LPS endotoxic shock model in male BALB/c mice, where IL-1β inhibition is monitored in different tissues.
Carboxylic Acid Reductase Can Catalyze Ester Synthesis in Aqueous Environments
Pongpamorn, Pornkanok,Kiattisewee, Cholpisit,Kittipanukul, Narongyot,Jaroensuk, Juthamas,Trisrivirat, Duangthip,Maenpuen, Somchart,Chaiyen, Pimchai
supporting information, p. 5749 - 5753 (2021/02/01)
Most of the well-known enzymes catalyzing esterification require the minimization of water or activated substrates for activity. This work reports a new reaction catalyzed by carboxylic acid reductase (CAR), an enzyme known to transform a broad spectrum of carboxylic acids into aldehydes, with the use of ATP, Mg2+, and NADPH as co-substrates. When NADPH was replaced by a nucleophilic alcohol, CAR from Mycobacterium marinum can catalyze esterification under aqueous conditions at room temperature. Addition of imidazole, especially at pH 10.0, significantly enhanced ester production. In comparison to other esterification enzymes such as acyltransferase and lipase, CAR gave higher esterification yields in direct esterification under aqueous conditions. The scalability of CAR catalyzed esterification was demonstrated for the synthesis of cinoxate, an active ingredient in sunscreen. The CAR esterification offers a new method for green esterification under high water content conditions.
Isolation and structure–activity relationship studies of jacaranones: Anti-inflammatory quinoids from the Cuban endemic plant Jacaranda arborea (Bignoniaceae)
Hirukawa, Minako,Zhang, Menghua,Echenique-Diaz, Lazaro M.,Mizota, Koji,Ohdachi, Satoshi D.,Begué-Quiala, Gerardo,Delgado-Laba?ino, Jorge L.,Gámez-Díez, Jorgelino,Alvarez-Lemus, José,Machado, Leandro Galano,Nú?ez, Miguel Suárez,Shibata, Takahiro,Kigoshi, Hideo,Kita, Masaki
, (2020/06/03)
The Cuban endemic plant Jacaranda arborea (Bignoniaceae) has been traditionally used in folk medicine as an acaricide and for acne treatment. Two known quinoids, methyl (1-hydroxy-4-oxocyclohexa-2,5-dien-1-yl)acetate (jacaranone) (1) and its ethyl ester 2 were isolated from this species as anti-inflammatory substances. Compound 1 prominently inhibited the production of TNF-α in both LPS-treated macrophages and mice, with low toxicity. Structure-activity relationship studies revealed that the high electrophilicity of 1 as a Michael acceptor played an important role in these effects. Unlike in previous studies, such as those on antitumor, anti-oxidant, and anti-malarial activities, ester derivatives of 1 retained their potent anti-inflammatory activity. Our results suggest that jacaranones may target specific biomacromolecule(s) at lower concentrations than hitherto expected to exhibit potent activities.
A deprotection procedure using SO3H silica gel to remove non-silyl protecting groups
Karaki, Fumika,Kuwada, Miki,Tajiri, Saki,Kanda, Misaki,Yanai, Mari,Kamimura, Mitsuhiro,Itoh, Kennosuke,Fujii, Hideaki
, p. 212 - 220 (2019/05/06)
Protecting groups are indispensable in organic synthesis and there is a great need for a variety of deprotection methods. Here, we investigated the scope of the application of a deprotection procedure using SO3H silica gel, which we have previously reported as a desilylation procedure. Under these conditions, -OMOM, -OSEM, -OTHP, and -OAc groups and dimethyl acetal were cleaved. Pivaloyloxy, benzyloxy and methoxy carbonyl groups remained intact and selective deprotection of TBS groups in the presence of other protecting groups was accomplished. We succeeded in cleaving an acetyl group on a secondary alcohol in a highly polar nortropine derivative. Our findings here provide another deprotection option and would be helpful in the synthesis of multifunctional compounds.
Enantioselective α-Benzylation of Acyclic Esters Using π-Extended Electrophiles
Schwarz, Kevin J.,Yang, Chao,Fyfe, James W. B.,Snaddon, Thomas N.
supporting information, p. 12102 - 12105 (2018/09/11)
The first asymmetric cooperative Lewis base/palladium catalyzed benzylic alkylation of acyclic esters is reported. This reaction proceeds via stereodefined C1-ammonium enolate nucleophiles. Critical to its success was the identification of benzylic phosphate electrophiles, which were uniquely reactive. Alkylated products were obtained with very high levels of enantioselectivity, and this method has been applied toward the synthesis of the thrombin inhibitor DX-9065a.
