- A Diverse Library of Chiral Cyclopropane Scaffolds via Chemoenzymatic Assembly and Diversification of Cyclopropyl Ketones
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Chiral cyclopropane rings are key pharmacophores in pharmaceuticals and bioactive natural products, making libraries of these building blocks a valuable resource for drug discovery and development campaigns. Here, we report the development of a chemoenzymatic strategy for the stereoselective assembly and structural diversification of cyclopropyl ketones, a highly versatile yet underexploited class of functionalized cyclopropanes. An engineered variant of sperm whale myoglobin is shown to enable the highly diastereo- and enantioselective construction of these molecules via olefin cyclopropanation in the presence of a diazoketone carbene donor reagent. This biocatalyst offers a remarkably broad substrate scope, catalyzing this reaction with high stereoselectivity across a variety of vinylarene substrates as well as a range of different α-aryl and α-alkyl diazoketone derivatives. Chemical transformation of these enzymatic products enables further diversification of these molecules to yield a collection of structurally diverse cyclopropane-containing scaffolds in enantiopure form, including core motifs found in drugs and natural products as well as novel structures. This work illustrates the power of combining abiological biocatalysis with chemoenzymatic synthesis for generating collections of optically active scaffolds of high value for medicinal chemistry and drug discovery.
- Nam, Donggeon,Steck, Viktoria,Potenzino, Robert J.,Fasan, Rudi
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p. 2221 - 2231
(2021/02/16)
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- Remote Regioselective Radical C-H Functionalization of Unactivated C-H Bonds in Amides: The Synthesis of gem-Difluoroalkenes
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The site-selective functionalization of unactivated aliphatic amines is an attractive and challenging synthetic approach. We herein report a general strategy for the remote site-selective functionalization of unactivated C(sp3)-H bonds in amides by photogenerated amidyl radicals to form gem-difluoroalkenes with trifluoromethyl-substituted alkenes. The site selectivity is controlled by a 1,5-hydrogen atom transfer (HAT) process of the amide. This photocatalyzed transformation shows both chemo- and site-selectivity, facilitating the formation of a secondary, tertiary, or quaternary carbon center.
- Hu, Qu-Ping,Cheng, Jing,Wang, Ying,Shi, Jie,Wang, Bi-Qin,Hu, Ping,Zhao, Ke-Qing,Pan, Fei
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supporting information
p. 4457 - 4462
(2021/05/26)
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- Direct and Enantioselective Aldol Reactions Catalyzed by Chiral Nickel(II) Complexes
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A direct and asymmetric aldol reaction of N-acyl thiazinanethiones with aromatic aldehydes catalyzed by chiral nickel(II) complexes is reported. The reaction gives the corresponding O-TIPS-protected anti-aldol adducts in high yields and with remarkable stereocontrol and atom economy. Furthermore, the straightforward removal of the achiral scaffold provides enantiomerically pure intermediates of synthetic interest, which involve precursors for anti-α-amino-β-hydroxy and α,β-dihydroxy carboxylic derivatives. Theoretical calculations explain the observed high stereocontrol.
- Kennington, Stuart C. D.,Teloxa, Saul F.,Mellado-Hidalgo, Miguel,Galeote, Oriol,Puddu, Sabrina,Bellido, Marina,Romea, Pedro,Urpí, Fèlix,Aullón, Gabriel,Font-Bardia, Mercè
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supporting information
p. 15307 - 15312
(2021/06/11)
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- Decarboxylative Borylation of mCPBA-Activated Aliphatic Acids
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A decarboxylative borylation of aliphatic acids for the synthesis of a variety of alkylboronates has been developed by mixing m-chloroperoxybenzoic acid (mCPBA)-activated fatty acids with bis(catecholato)diboron in N,N-dimethylformamide (DMF) at room temperature. A radical chain process is involved in the reaction which initiates from the B-B bond homolysis followed by the radical transfer from the boron atom to the carbon atom with subsequent decarboxylation and borylation.
- Wei, Dian,Liu, Tu-Ming,Zhou, Bo,Han, Bing
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supporting information
p. 234 - 238
(2020/01/02)
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- Modular Tuning of Electrophilic Reactivity of Iridium Nitrenoids for the Intermolecular Selective α-Amidation of β-Keto Esters
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We report herein an Ir-catalyzed intermolecular amino group transfer to β-keto esters (amides) to access α-aminocarbonyl products with excellent chemoselectivity. The key strategy was to engineer electrophilicity of the putative Ir-nitrenoids by tuning electronic property of the κ2-N,O chelating ligands, thus facilitating nucleophilic addition of enol π-bonds of 1,3-dicarbonyl substrates.
- Lee, Minhan,Jung, Hoimin,Kim, Dongwook,Park, Jung-Woo,Chang, Sukbok
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supporting information
p. 11999 - 12004
(2020/08/06)
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- Photocatalytic Intramolecular C-H Amination Using N-Oxyureas as Nitrene Precursors
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Nitrenes are remarkable high-energy chemical species that enable direct C-N bond formation, typically via controlled reactions of metal-stabilized nitrenes. Here, in contrast, the combined use of photocatalysis with careful engineering of the precursor enabled C-H amination forming imidazolidinones and related nitrogen heterocycles from readily accessible hydroxylamine precursors. Preliminary mechanistic results are consistent with the formation of free carbamoyl triplet nitrenes as reactive intermediates.
- Ivanovich, Ryan A.,Polat, Dilan E.,Beauchemin, André M.
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supporting information
p. 6360 - 6364
(2020/09/02)
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- Hydroxamate-Based Selective Macrophage Elastase (MMP-12) Inhibitors and Radiotracers for Molecular Imaging
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Macrophage elastase [matrix metalloproteinase (MMP)-12] is the most upregulated MMP in abdominal aortic aneurysm (AAA) and, hence, MMP-12-targeted imaging may predict AAA progression and rupture risk. Here, we report the design, synthesis, and evaluation of three novel hydroxamate-based selective MMP-12 inhibitors (CGA, CGA-1, and AGA) and the methodology to obtain MMP-12 selectivity from hydroxamate-based panMMP inhibitors. Also, we report two 99mTc-radiotracers, 99mTc-AGA-1 and 99mTc-AGA-2, derived from AGA. 99mTc-AGA-2 displayed faster blood clearance in mice and better radiochemical stability compared to 99mTc-AGA-1. Based on this, 99mTc-AGA-2 was chosen as the lead tracer and tested in murine AAA. 99mTc-AGA-2 uptake detected by autoradiography was significantly higher in AAA compared to normal aortic regions. Specific binding of the tracer to MMP-12 was demonstrated through ex vivo competition. Accordingly, this study introduces a novel family of selective MMP-12 inhibitors and tracers, paving the way for further development of these agents as therapeutic and imaging agents.
- Gona, Kiran,Toczek, Jakub,Ye, Yunpeng,Sanzida, Nowshin,Golbazi, Arvene,Boodagh, Parnaz,Salarian, Mani,Jung, Jae-Joon,Rajendran, Saranya,Kukreja, Gunjan,Wu, Terence L.,Devel, Laurent,Sadeghi, Mehran M.
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p. 15037 - 15049
(2020/11/30)
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- Discovery of TD-0212, an Orally Active Dual Pharmacology AT1 Antagonist and Neprilysin Inhibitor (ARNI)
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Dual inhibition of angiotensin-converting enzyme (ACE) and neprilysin (NEP) by drugs such as omapatrilat produces superior antihypertensive efficacy relative to ACE inhibitors but is associated with a higher risk of life-threatening angioedema due to bradykinin elevations. We hypothesized that dual AT1 (angiotensin II type 1 receptor) blockade and NEP inhibition with a single molecule would produce similar antihypertensive efficacy to omapatrilat without the risk of angioedema since ACE (the rate limiting enzyme in bradykinin metabolism) would remain uninhibited. Merging the structures of losartan (an AT1 antagonist) and thiorphan (a NEP inhibitor) led to the discovery of a novel series of orally active, dual AT1 antagonist/NEP inhibitors (ARNIs) exemplified by compound 35 (TD-0212). In models of renin-dependent and -independent hypertension, 35 produced blood pressure reductions similar to omapatrilat and combinations of AT1 receptor antagonists and NEP inhibitors. Upper airway angioedema risk was assessed in a rat tracheal plasma extravasation (TPE) model. Unlike omapatrilat, 35 did not increase TPE at antihypertensive doses. Compound 35 therefore provides the enhanced activity of dual AT1/NEP inhibition with a potentially lower risk of angioedema relative to dual ACE/NEP inhibition.
- McKinnell, R. Murray,Fatheree, Paul,Choi, Seok-Ki,Gendron, Roland,Jendza, Keith,Olson Blair, Brooke,Budman, Joe,Hill, Craig M.,Hegde, Laxminarayan G.,Yu, Cecile,McConn, Donavon,Hegde, Sharath S.,Marquess, Daniel G.,Klein, Uwe
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supporting information
p. 86 - 91
(2019/01/04)
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- Synthetic Utility of N-Benzoyloxyamides as an Alternative Precursor of Acylnitrenoids for γ-Lactam Formation
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Described herein is the development of a new entry of acylnitrenoid precursors for γ-lactam synthesis via an intramolecular C-H amidation reaction. Upon Ir catalysis, N-benzoyloxyamides serve as efficient substrates to afford 5-membered amides. Mechanistic studies revealed that the generation of a putative Ir-carbonylnitrenoid via N-O bond cleavage is facilitated by the chelation of countercations. This protocol offers a convenient and step-economic route to γ-lactams starting from the corresponding carboxylic acids.
- Huh, Soohee,Hong, Seung Youn,Chang, Sukbok
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supporting information
p. 2808 - 2812
(2019/04/17)
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- Rational design of a new class of toll-like receptor 4 (tlr4) tryptamine related agonists by means of the structure- and ligand-based virtual screening for vaccine adjuvant discovery
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In order to identify novel lead structures for human toll-like receptor 4 (hTLR4) modulation virtual high throughput screening by a peta-flops-scale supercomputer has been performed. Based on the in silico studies, a series of 12 compounds related to tryptamine was rationally designed to retain suitable molecular geometry for interaction with the hTLR4 binding site as well as to satisfy general principles of drug-likeness. The proposed compounds were synthesized, and tested by in vitro and ex vivo experiments, which revealed that several of them are capable to stimulate hTLR4 in vitro up to 25% activity of Monophosphoryl lipid A. The specific affinity of the in vitro most potent substance was confirmed by surface plasmon resonance direct-binding experiments. Moreover, two compounds from the series show also significant ability to elicit production of interleukin 6.
- Honegr, Jan,Dolezal, Rafael,Malinak, David,Benkova, Marketa,Soukup, Ondrej,De Almeida, Joyce S. F. D.,Franca, Tanos C. C.,Kuca, Kamil,Prymula, Roman
-
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- Cobalt-Catalyzed Enantioselective Negishi Cross-Coupling of Racemic α-Bromo Esters with Arylzincs
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The first cobalt-catalyzed enantioselective Negishi cross-coupling reaction, and the first arylation of α-halo esters with arylzinc halides, are disclosed. Employing a cobalt-bisoxazoline catalyst, various α-arylalkanoic esters were synthesized in excellent enantioselectivities and yields (up to 97 % ee and 98 % yield). A diverse range of functional groups, including ether, halide, thioether, silyl, amine, ester, acetal, amide, olefin and heteroaromatics is tolerated by this method. This method was suitable for gram-scale reactions, enabling the synthesis of (R)-xanthorrhizol with high enantiopurity. Radical clock experiments support the intermediacy of radicals.
- Liu, Feipeng,Zhong, Jiangchun,Zhou, Yun,Gao, Zidong,Walsh, Patrick J.,Wang, Xueyang,Ma, Sijie,Hou, Shicong,Liu, Shangzhong,Wang, Minan,Wang, Min,Bian, Qinghua
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supporting information
p. 2059 - 2064
(2018/02/14)
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- Design, synthesis, and evaluation of cystargolide-based β-lactones as potent proteasome inhibitors
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The peptidic β-lactone proteasome inhibitors (PIs) cystargolides A and B were used to conduct structure-activity relationship (SAR) studies in order to assess their anticancer potential. A total of 24 different analogs were designed, synthesized and evaluated for proteasome inhibition, for cytotoxicity towards several cancer cell lines, and for their ability to enter intact cells. X-ray crystallographic analysis and subunit selectivity was used to determine the specific subunit binding associated with the structural modification of the β-lactone (P1), peptidic core, (Px and Py), and end-cap (Pz) of our scaffold. The cystargolide derivative 5k, structurally unique at both Py and P1, exhibited the most promising inhibitory activity for the β5 subunit of human proteasomes (IC50 = 3.1 nM) and significant cytotoxicity towards MCF-7 (IC50 = 416 nM), MDA-MB-231 (IC50 = 74 nM) and RPMI 8226 (IC50 = 41 nM) cancer cell lines. Cellular infiltration assays revealed that minor structural modifications have significant effects on the ability of our PIs to inhibit intracellular proteasomes, and we identified 5k as a promising candidate for continued therapeutic studies. Our novel drug lead 5k is a more potent proteasome inhibitor than carfilzomib with mid-to-low nanomolar IC50 measurements and it is cytotoxic against multiple cancer cell lines at levels approaching those of carfilzomib.
- Niroula, Doleshwar,Hallada, Liam P.,Le Chapelain, Camille,Ganegamage, Susantha K.,Dotson, Devon,Rogelj, Snezna,Groll, Michael,Tello-Aburto, Rodolfo
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supporting information
p. 962 - 977
(2018/09/04)
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- Photoinduced Remote Functionalization of Amides and Amines Using Electrophilic Nitrogen Radicals
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The selective functionalization of C(sp3)?H bonds at distal positions to functional groups is a challenging task in synthetic chemistry. Reported here is a photoinduced radical cascade strategy for the divergent functionalization of amides and protected amines. The process is based on the oxidative generation of electrophilic amidyl radicals and their subsequent transposition by 1,5-H-atom transfer, resulting in remote fluorination, chlorination and, for the first time, thioetherification, cyanation, and alkynylation. The process is tolerant of most common functional groups and delivers useful building blocks that can be further elaborated. The utility of this strategy is demonstrated through the late-stage functionalization of amino acids and a dipeptide.
- Morcillo, Sara P.,Dauncey, Elizabeth M.,Kim, Ji Hye,Douglas, James J.,Sheikh, Nadeem S.,Leonori, Daniele
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supporting information
p. 12945 - 12949
(2018/09/14)
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- Primary, Secondary, and Tertiary γ-C(sp3)-H Vinylation of Amides via Organic Photoredox-Catalyzed Hydrogen Atom Transfer
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An efficient strategy for primary, secondary and tertiary aliphatic γ-C(sp3)-H vinylation of amides with alkenylboronic acids is reported. These reactions are catalyzed by visible-light organic photoredox agents. Regioselective γ-C(sp3)-H vinylation of amides is controlled by a 1,5-hydrogen atom transfer of an amidyl radical generated in situ.
- Chen, Hui,Guo, Liangliang,Yu, Shouyun
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supporting information
p. 6255 - 6259
(2018/10/05)
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- Direct C-C Bond Formation from Alkanes Using Ni-Photoredox Catalysis
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A method for direct cross coupling between unactivated C(sp3)-H bonds and chloroformates has been accomplished via nickel and photoredox catalysis. A diverse range of feedstock chemicals, such as (a)cyclic alkanes and toluenes, along with late-stage intermediates, undergo intermolecular C-C bond formation to afford esters under mild conditions using only 3 equiv of the C-H partner. Site selectivity is predictable according to bond strength and polarity trends that are consistent with the intermediacy of a chlorine radical as the hydrogen atom-abstracting species.
- Ackerman, Laura K. G.,Martinez Alvarado, Jesus I.,Doyle, Abigail G.
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p. 14059 - 14063
(2018/10/24)
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- Copper-Catalyzed Bromination of C(sp3)?H Bonds Distal to Functional Groups
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Selective bromination of γ-methylene C(sp3)?H bonds of aliphatic amides and δ-methylene C(sp3)?H bonds of nosyl-protected alkyl amines are developed using NBS as the brominating reagent and catalytic amount of CuII/phenanthroline complexes as the catalyst. Aryl and benzylic C?H bonds at other locations remain intact during this directed radical abstraction reaction.
- Liu, Tao,Myers, Michael C.,Yu, Jin-Quan
-
supporting information
p. 306 - 309
(2016/12/30)
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- Antiprotozoal glutathione derivatives with flagellar membrane binding activity against T. brucei rhodesiense
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A new series of N-substituted S-(2,4-dinitrophenyl)glutathione dibutyl diesters were synthesized to improve in vitro anti-protozoal activity against the pathogenic parasites Trypanosoma brucei rhodesiense, Trypanosoma cruzi and Leishmania donovani. The results obtained indicate that N-substituents enhance the inhibitory properties of glutathione diesters whilst showing reduced toxicity against KB cells as in the cases of compounds 5, 9, 10, 16, 18 and 19. We suggest that the interaction of N-substituted S-(2,4-dinitrophenyl) glutathione dibutyl diesters with T. b. brucei occurs mainly by weak hydrophobic interactions such as London and van der Waals forces. A QSAR study indicated that the inhibitory activity of the peptide is associated negatively with the average number of C atoms, NCand positively to SZX,the ZX shadow a geometric descriptor related to molecular size and orientation of the compound. HPLC-UV studies in conjunction with optical microscopy indicate that the observed selectivity of inhibition of these compounds against bloodstream form T. b. brucei parasites in comparison to L. donovani under the same conditions is due to intracellular uptake via endocytosis in the flagellar pocket.
- Daunes, Sylvie,Yardley, Vanessa,Croft, Simon L.,D'Silva, Claudius
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p. 1329 - 1340
(2017/02/10)
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- Directed γ-C(sp3)-H Alkylation of Carboxylic Acid Derivatives through Visible Light Photoredox Catalysis
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Visible light photoredox catalysis enables direct γ- C(sp3)-H alkylation of saturated aliphatic carbonyl compounds. Electron-deficient alkenes are used as the coupling partners in this reaction. Distinguished site selectivity is controlled by the predominant 1,5-hydrogen atom transfer of an amidyl radical generated in situ.
- Chen, Dian-Feng,Chu, John C. K.,Rovis, Tomislav
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supporting information
p. 14897 - 14900
(2017/10/31)
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- HETEROCYCLIC KINASE INHIBITORS
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The present disclosure is generally directed to compounds which can inhibit AAK1 (adaptor associated kinase 1), compositions comprising such compounds, and methods for inhibiting AAK1.
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Page/Page column 177-178
(2016/05/19)
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- A dual inhibitor of matrix metalloproteinases and a disintegrin and metalloproteinases, [18F]FB-ML5, as a molecular probe for non-invasive MMP/ADAM-targeted imaging
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Background Numerous clinical studies have shown a correlation between increased matrix metalloproteinase (MMP)/a disintegrin and metalloproteinase (ADAM) activity and poor outcome of cancer. Various MMP inhibitors (MMPIs) have been developed for therapeutic purposes in oncology. In addition, molecular imaging of MMP/ADAM levels in vivo would allow the diagnosis of tumors. We selected the dual inhibitor of MMPs and ADAMs, ML5, which is a hydroxamate-based inhibitor with affinities for many MMPs and ADAMs. ML5 was radiolabelled with 18F and the newly obtained radiolabelled inhibitor was evaluated in vitro and in vivo. Materials and methods ML5 was radiolabelled by direct acylation with N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB) for PET (positron emission tomography). The resulting radiotracer [18F]FB-ML5 was evaluated in vitro in human bronchial epithelium 16HBE cells and breast cancer MCF-7 cells. The non-radioactive probe FB-ML5 and native ML5 were tested in a fluorogenic inhibition assay against MMP-2, -9, -12 and ADAM-17. The in vivo kinetics of [18F]FB-ML5 were examined in a HT1080 tumor-bearing mouse model. Specificity of probe binding was examined by co-injection of 0 or 2.5 mg/kg ML5. Results ML5 and FB-ML5 showed high affinity for MMP-2, -9, -12 and ADAM-17; indeed IC50 values were respectively 7.4 ± 2.0, 19.5 ± 2.8, 2.0 ± 0.2 and 5.7 ± 2.2 nM and 12.5 ± 3.1, 31.5 ± 13.7, 138.0 ± 10.9 and 24.7 ± 2.8 nM. Radiochemical yield of HPLC-purified [18F]FB-ML5 was 13-16% (corrected for decay). Cellular binding of [18F]FB-ML5 was reduced by 36.6% and 27.5% in MCF-7 and 16HBE cells, respectively, after co-incubation with 10 μM of ML5. In microPET scans, HT1080 tumors exhibited a low and homogeneous uptake of the tracer. Tumors of mice injected with [18F]FB-ML5 showed a SUVmean of 0.145 ± 0.064 (n = 6) which decreased to 0.041 ± 0.027 (n = 6) after target blocking (p 18F. [18F]FB-ML5 demonstrated rather low binding in ADAM-17 overexpressing cell lines. [18F]FB-ML5 uptake showed significant reduction in the HT1080 tumor in vivo after co-injection of ML5. [18F]FB-ML5 may be suitable for the visualization/quantification of diseases overexpressing simultaneously MMPs and ADAMs.
- Matusiak, Nathalie,Castelli, Riccardo,Tuin, Adriaan W.,Overkleeft, Herman S.,Wisastra, Rosalina,Dekker, Frank J.,Prély, Laurette M.,Bischoff, Rainer P.M.,Van Waarde, Aren,Dierckx, Rudi A.J.O.,Elsinga, Philip H.
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p. 192 - 202
(2015/02/19)
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- Silver-mediated oxidative aliphatic C-H trifluoromethylthiolation
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The first example of a practical and direct trifluoromethylthiolation reaction of unactivated aliphatic C-H bonds employs a silver-based reagent. The reaction is operationally simple, scalable, and proceeds under aqueous conditions in air. Furthermore, its broad scope and good functional-group compatibility were demonstrated by applying this method to the selective trifluoromethylthiolation of natural products and natural-product derivatives.
- Guo, Shuo,Zhang, Xiaofei,Tang, Pingping
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supporting information
p. 4065 - 4069
(2015/03/30)
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- γ,δ,ε-C(sp3)-H Functionalization through Directed Radical H-Abstraction
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Aliphatic amides are selectively functionalized at the γ- and δ-positions through directed radical 1,5 and 1,6 H-abstractions, respectively. The initially formed γ- or δ-lactams are intercepted by N-iodosuccinimide and trimethylsilyl azide, leading to double and triple C-H functionalizations at the γ-, δ-, and ε-positions. This new reactivity is exploited to convert alkyls into amino alcohols and allylic amines.
- Liu, Tao,Mei, Tian-Sheng,Yu, Jin-Quan
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supporting information
p. 5871 - 5874
(2015/05/27)
-
- Cobalt-bisoxazoline-catalyzed asymmetric kumada cross-coupling of racemic α-bromo esters with aryl grignard reagents
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The first cobalt-catalyzed asymmetric Kumada cross-coupling with high enantioselectivity has been developed. The reaction affords a unique strategy for the enantioselective arylation of α-bromo esters catalyzed by a cobalt-bisoxazoline complex. A variety of chiral α-arylalkanoic esters were prepared in excellent enantioselectivity and yield (up to 97% ee and 96% yield). The arylated products were transformed into α-arylcarboxylic acids and primary alcohols without erosion of ee. The new enantioenriched α-arylpropionic esters synthesized herein are potentially useful in the development of nonsteroidal anti-inflammatory drugs. This method was conducted on gram-scale and applied to the synthesis of highly enantioenriched (S)-fenoprofen and (S)-ar-turmerone.
- Mao, Jianyou,Liu, Feipeng,Wang, Min,Wu, Lin,Zheng, Bing,Liu, Shangzhong,Zhong, Jiangchun,Bian, Qinghua,Walsh, Patrick J.
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supporting information
p. 17662 - 17668
(2015/02/02)
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- ISATIN AND OXINDOLE COMPOUNDS
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Provided herein are compounds of the formula (I): as well as pharmaceutically acceptable salts thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment of metabolic diseases and disorders such as, for example, type II diabetes mellitus.
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Page/Page column 14
(2012/06/16)
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- The stereoselective total synthesis of (-)-dihydrotetrabenazine
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A highly stereoselective synthesis of (-)-dihydrotetrabenazine has been accomplished using (R)-tert-butanesulfinamide as a chiral source. The synthesis involves the allylation of chiral N-sulfinyl imine followed by ring closure of the resulting secondary amide with a tethered halide and the Evans-Aldol reaction as key steps.
- Siva Senkar Reddy,Srinivas Reddy,Yadav,Subba Reddy
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supporting information
p. 6916 - 6918
(2013/01/15)
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- Antinociceptive effect of extracts and compounds from Hofmeisteria schaffneri
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Ethnopharmacological relevance: Hofmeisteria schaffneri (Asteraceae) is a medicinal plant widely commercialized in the most important Markets of Mexico City for the treatment of gastro-intestinal complaints and skin afflictions. Aim of the study: The main goals of this study were to establish the potential acute toxicity and the antinociceptive activity in animal models of several preparations and compounds from Hofmeisteria schaffneri. Materials and methods: The aqueous and organic extracts as well as the essential oil of Hofmeisteria schaffneri were prepared by infusion, maceration and hydrodistillation, respectively. Investigation of the acute toxicity was accomplished by the Lorke method. The antinociceptive effect was assessed using the writhing and the hot plate tests. Natural compounds were isolated by standard phytochemical procedures. In addition, a few thymol esters were prepared by chemical synthesis. The stability of natural and synthetic esters was qualitatively analyzed by measuring their susceptibility to hydrolysis by pig liver estearase and mouse plasma at 37°C. Results: The LD50 for each preparation tested was higher than 5000mg/kg revealing that they were not toxic to mice after exposure for short space of time. On the other hand, the extracts showed significant antinociceptive effect when tested in the hot plate model. The most active natural product as antinociceptive agent was hofmeisterin III (1) which also was the most stable in the stability study. Its pharmacological effect seems to be partially mediated by an opioid mechanism since naloxone inhibits its action. Using compound 1 as a lead molecule, several synthetic thymol esters were prepared and only compounds 13, 15 and 17 were antinoceptive at the dose of 1mg/kg. Conclusions: The present investigation provided evidence of the efficacy of several preparations of Hofmeisteria schaffneri as antinociceptive agents. The most active preparation was the essential oil which contained large amount of hofmeisterin III (1) and other thymol derivatives. Some novel synthetic analogs of hofmeisterin III with antinociceptive properties were discovered. The nature of the ester chain of these analogs did not have a clear impact on the antinociceptive activity. The phyto-preparations analyzed in this study were not toxic to mice according to the Lorke's test; therefore considering their long term use of the plant they might be secure for human consumption.
- Angeles-Lopez, Guadalupe,Perez-Vasquez, Araceli,Hernandez-Luis, Francisco,Deciga-Campos, Myrna,Bye, Robert,Linares, Edelmira,Mata, Rachel
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experimental part
p. 425 - 432
(2011/11/14)
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- Biomimetic synthesis of a new class of bacterial signaling molecules
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The first synthesis of a newly discovered class of bacterial signaling molecules from Streptomyces coelicolor has been developed. These molecules, known as the methylenomycin furans (MMFs), trigger production of the antibiotic methylenomycin. The synthesis features a scandium triflatecatalyzed domino reaction of β-ketoesters and dihydroxyacetone yielding 2,3,4-substituted furans. The proposed reaction sequence (aldol reaction, cyclization, and dehydrative aromatization) may be reminiscent of the biosynthetic reaction in which dihydroxyacetone phosphate and a β-ketothioester are condensed by an enzyme.
- Davis, Jesse B.,Bailey, J. Daniel,Sello, Jason K.
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supporting information; experimental part
p. 2984 - 2987
(2009/12/05)
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- DUAL-ACTING ANTIHYPERTENSIVE AGENTS
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The invention relates to compounds having the formula: (I) wherein: Ar, r, R3, Z, X, and R5-7 are as defined in the specification, or a pharmaceutically acceptable salt thereof. These compounds have AT1 receptor antagonist activity and neprilysin inhibition activity. The invention also relates to pharmaceutical compositions comprising such compounds; methods of using such compounds; and process and intermediates for preparing such compounds.
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Page/Page column 89-90
(2009/04/25)
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- N- (1, 1, 1, 3, 3, 3-HEXAFLUORO-2-HYDROXYPROPAN-2-YL) BENZYL-N' -ARYLCARBONYLPIPERAZ INE DERIVATIVES
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101 Abstract. The present invention relates tohexafluoroisopropanol derivativeshaving the general formula I X O N N Y OH F 3 C CF 3 A R 1 R 2 R 3 ( ) n W Z B R 6 5 Formula I to pharmaceutical compositions comprising the same and to the use of these hexafluoroisopropanol derivatives inthe treatment of atherosclerosis
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Page/Page column 43
(2009/12/23)
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- Dual-acting antihypertensive agents
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The invention is directed to compounds having the formula: wherein: Ar, r, Y, Z, Q, W, X, and R5-7 are as defined in the specification, and pharmaceutically acceptable salts thereof. These compounds have AT1 receptor antagonist activity and neprilysin inhibition activity. The invention is also directed to pharmaceutical compositions comprising such compounds; methods of using such compounds; and process and intermediates for preparing such compounds.
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Page/Page column 41
(2008/12/04)
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- Dual-acting antihypertensive agents
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The invention is directed to compounds of formula I: wherein Ar, r, R3, X, and R5-7 are as defined in the specification, and pharmaceutically acceptable salts thereof. The compounds of formula I have AT1 receptor antagonist activity and neprilysin inhibition activity. The invention is also directed to pharmaceutical compositions comprising such compounds; methods of using such compounds; and a process and intermediates for preparing such compounds.
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Page/Page column 42
(2008/12/07)
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- Catalytic asymmetric hiyama cross-couplings of racemic α-bromo esters
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The first catalytic asymmetric cross-coupling of α-halo carbonyl compounds with aryl metal reagents has been developed, thereby generating synthetically useful α-aryl carboxylic acid derivatives in good enantiomeric excess. The method can also be applied to enantioselective alkenylation reactions. Copyright
- Dai, Xing,Strotman, Neil A.,Fu, Gregory C.
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p. 3302 - 3303
(2008/10/09)
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- 5,6-Diphenyl-1,2,4-Triazinic Dimeric Derivatives and the Use Thereof in the Form of Sun-Protective Agents
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The invention relates to 5,6-diphenyl-1,2,4-triazinic compounds of general formula (I), wherein identical or different R1, R2, R3 and R4 represent a hydrogen, fluoride, chloride or bromine atom, C1 to C12 linear or branched alkyl, C1 A C18 linear or branched hydroxy, alkoxy poly(ethoxy)-alkoxy with a C1 to C4 alkyl fragment and an ethoxy number ranging from 1 to 4, amino or mono or di-alkylamino with a C1 to C4 alkyl fragment group, X is ortho-, meta- or paraphenylene, 4,4′-biphenylene, 2,4- or 2,6- or 3,4- or 3,5-pyridinylene, 2,2′-bipyridinylene, meta- or paraphenylenediamino, ethylenediamine, 2,2′-piperazinylene, diacyl of formula -(R4CO)2-, wherein r represents a phenyl radical, a 3 to 10 carbon, phenanthrene or anthracene atoms alkyl chain except 1,4-bis(5,6-diphenyl-1,2,4-triazin-3-yl)benzene of 2,4-bis(5,6-diphenyl-1,2,4-triazin-3-yl)pyridine and of 2,6-bis(5,6-diphenyl-1,2,4-triazin-3-yl)pyridine, to cosmetic compositions containing said compounds and to the use thereof in the form of sun filters or light-protective agents.
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Page/Page column 14
(2008/12/04)
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- Enantioselective synthesis of beta-amino acids using hexahydrobenzoxazolidinones as chiral auxiliaries
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A practical synthetic route for the asymmetric synthesis of β2-amino acids is described. In the first step, the procedure involves the N-acylation of readily available, enantiopure hexahydrobenzoxazolidinone (4R,5R)-1 with 3-methylbutanoyl chloride 2, 4-methylpentanoic acid 3, and 3-(1-tert-butoxycarbonyl)-1H-indol-3-yl)propanoic acid 4 to afford derivatives 5a, 5b, and 5c, respectively, which were alkylated with high diastereoselectivity by means of reaction between their sodium enolates and benzyl bromoacetate. Removal of the chiral auxiliary from the alkylated products followed by hydrogenation and hydrolysis gave β2-amino acids (S)-10a, (S)-10b, and (S)-10c, which were N-protected with Fmoc. Enantiomeric (R)-10a-c were similarly prepared from the isomeric hexahydrobenzoxazolidinone (4S,5S)-1; thus, the route presented here provides access to both enantiomers of valuable highly enantioenriched β2-amino acids.
- Reyes-Rangel, Gloria,Jimenez-Gonzalez, Erika,Olivares-Romero, Jose Luis,Juaristi, Eusebio
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experimental part
p. 2839 - 2849
(2009/06/18)
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- Vanillin esters in reactions with indan-1,3-dione
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2-Methoxy-4-(12-oxo-12H-benzo[f]indeno[1,2-b]quinolin-13-yl)phenyl esters of carboxylic acids were synthesized by the three component condensation of indan-1,3-dione, 2-naphthylamine, and O-acylvanillin. 2-Arylidenindan-1,3-diones formed during the reaction were isolated. Springer Science+Business Media, Inc. 2006.
- Kozlov,Basalaeva
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p. 1223 - 1228
(2008/09/21)
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- Room-temperature discotic nematic liquid crystals
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The use of discotic nematic liquid crystals instead of calamitic nematic liquid crystals to improve the viewing angle of a liquid crystal display device has recently been reported. Compared to the large number of calamitic molecules showing nematic phase at room temperature, the number of disk-shaped molecules showing subambient discotic nematic phase ND are rare. In this paper we present the design, synthesis, mesomorphic behaviour and structureproperty relationship of discotic nematic liquid crystals based on benzene multiyne core.
- Kumar, Sandeep,Varshney, Sanjay Kumar,Chauhan, Diwakar
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p. 241 - 250
(2007/10/03)
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- SuperQuat N-acyl-5,5-dimethyloxazolidin-2-ones for the asymmetric synthesis of α-alkyl and β-alkyl aldehydes
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The proclivity of α-branched N-2′-benzyl-3′-phenylpropionyl derivatives of (S)-4-benzyl-5,5-dimethyl-, (S)-4-phenyl-5,5-dimethyl-, (S)-4-isopropyl-5,5-dimethyl-, (S)-4-benzyl- and (S)-4-benzyl-5,5-diphenyl-oxazolidin-2-ones to generate directly 2-benzyl-3-phenylpropionaldehyde upon hydride reduction with DIBAL is investigated. The (S)-4-benzyl-5,5-dimethyl-derivative proved optimal for inhibition of endocyclic nucleophilic attack, giving 2-benzyl-3-phenylpropionaldehyde in good yield upon reduction. Application of this methodology for the asymmetric synthesis of chiral aldehydes via diastereoselective enolate alkylation of a range of (S)-N-acyl-4-benzyl-5,5-dimethyloxazolidin-2-ones to afford an array of α-substituted-N-acyl-5,5-dimethyloxazolidin-2-ones (85-94% de) and subsequent reduction with DIBAL afforded directly non-racemic α-substituted aldehydes without loss of stereochemical integrity (87-94% ee). The extension of this protocol for the asymmetric synthesis of β-substituted aldehydes is demonstrated, via the diastereoselective conjugate addition of a range of organocuprates to (S)-N-acyl-4-phenyl-5,5-dimethyloxazolidin-2-ones which proceeds with high diastereoselectivity (generally >95% de). Reduction of the conjugate addition products with DIBAL gives non-racemic β-substituted aldehydes in high yields and in high ee (generally >95% ee). This methodology is exemplified by the asymmetric synthesis of (R)-3-isopropenylhept-6-enal, which has previously been used in the synthesis of (3Z,6R)-3-methyl-6-isopropenyl-3,9-decadien-1-yl acetate, a component of the sex pheromones of the California red scale.
- Bull, Steven D.,Davies, Stephen G.,Nicholson, Rebecca L.,Sanganee, Hitesh J.,Smith, Andrew D.
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p. 2886 - 2899
(2007/10/03)
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- GABA and L-glutamic acid analogs for antiseizure treatment
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A compound of the formula wherein R1is a straight or branched alkyl group having from 1 to 6 carbon atoms, phenyl, or cycloalkyl having from 3 to 6 carbon atoms; R2is hydrogen or methyl; and R3is hydrogen, methyl or carboxyl; which is useful in the treatment of seizure disorders. Processes are disclosed for the preparation of the compound. Intermediates prepared during the synthesis of the compound are also disclosed.
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Page column 14, 18
(2008/06/13)
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- Small ring constrained peptidomimetics. Synthesis of epoxy peptidomimetics, inhibitors of cysteine proteases
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Different dipeptide analogues containing an oxirane ring in the place of the peptidic bond were prepared starting from naturally occurring amino acids. N-Fmoc-amino aldehydes were transformed into the corresponding methoxyvinyl derivatives through a Wittig reaction, and the addition of PhSeCl gave a series of different α-phenylselenyl aldehydes. Mukajiama reaction with silylketene acetals gave an intermediate product that was finally transformed into the desired oxiranyl peptidomimetics. Following this strategy we were able to control three new contiguous stereocenters starting from the enantiomerically pure amino acid. The dipeptide analogues could be used in SPPS on a SASRIN resin as the final epoxides were relatively unstable under acidic conditions. Moreover the synthesis of the single dipeptide mimetics was carried out on solid phase to generate a small library of epoxy peptidomimetics. Some of the products prepared in this work resulted as time-dependent reversible inhibitors of cysteine protease.
- Demarcus,Ganadu,Mura,Porcheddu,Quaranta,Reginato,Taddei
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p. 697 - 706
(2007/10/03)
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- Treatment of inflammatory and autoimmune diseases
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This invention is directed to the treatment of inflammatory and autoimmune diseases by administering proteasome inhibitors, ubiquitin pathway inhibitors, agents that interfere with the activation of NF-κB via the ubiquitin proteasome pathway, or mixtures thereof. The invention is further directed to the treatment of inflammatory and autoimmune diseases by administering an effective combination of a glucocorticoid and a proteasome inhibitor, ubiquitin pathway inhibitor, agent that interferes with the activation of NF-κB via the ubiquitin proteasome pathway, or mixture thereof. Pharmaceutical compositions comprising a combination of a glucocorticoid and a proteasome inhibitor, ubiquitin pathway inhibitor, agent that interferes with the activation of NF-κB via the ubiquitin proteasome pathway, or mixture thereof are also contemplated within the scope of the invention.
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- Matrix metalloprotease inhibitors
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Compounds of formula (I): STR1 as single stereoisomers or mixtures thereof and their pharmaceutically acceptable salts inhibit matrix metalloproteases, such as interstitial collagenases, and are useful in the treatment of mammals having disease states alleviated by the inhibition of such matrix metalloproteases, for example arthritic diseases or bone resorption disease, such as osteoporosis.
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- Matrix metalloprotease inhibitors
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Compounds of formula (I) and their pharmaceutically acceptable salts inhibit matrix metalloproteases, such as stromelysin, gelatinase, matrilysin and collagenase, and are useful in the treatment of mammals having disease-states alleviated by the inhibition of such matrix metalloproteases.
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- Synthesis of clasto-lactacystin beta-lactone and analogs thereof
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The present invention is directed to an improved synthesis of clasto-lactacystin- beta -lactone, and analogs thereof, that proceeds in fewer steps and in much greater overall yield than syntheses described in the prior art. The synthetic pathway relies upon a novel stereospecific synthesis of an oxazoline intermediate and a unique stereoselective addition of a formyl amide to the oxazoline. Also described are novel clasto-lactacystin- beta -lactones, and analogs thereof and their use as proteosome inhibitors.
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- MATRIX METALLOPROTEASE INHIBITORS
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Compounds of formula (I): STR1 as single stereoisomers or mixtures thereof and their pharmaceutically acceptable salts inhibit matrix metalloproteases, such as interstitial collagenases, and are useful in the treatment of mammals having disease states alleviated by the inhibition of such matrix metalloproteases, for example arthritic diseases or bone resorption diseases, such as osteoporosis.
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- Imidazopyridines as pharmaceutical agents
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Described herein are novel imidazopyridine derivatives of the formula I STR1 wherein R is STR2 and R1, R2, R3 and R4 are as defined in Patent Claim 1, and their salts, which exhibit antagonistic properties towards angiotensin II and can be used for the treatment of hypertension, aldosteronism, cardiac insufficiency and increased intraocular pressure, and of disorders of the central nervous system.
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- Molting hormonal and larvicidal activities of aliphatic acyl analogs of dibenzoylhydrazine insecticides
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Dibenzoylhydrazines are the nonsteroidal ecdysone agonists. Using comparative molecular field analysis, we previously found that the alkyl side chain of 20-hydroxyecdysone (20E) is three-dimensionally superposable with one of their two aryl moieties. To identify the aryl moiety that is better superposable on the alkyl chain, we synthesized compounds in which one of the two aryl groups of tebufenozide (N-t-butyl-N-3,5-dimethylbenzoyl-N'-4- ethylbenzoylhydrazine) is replaced by alkyl groups such as C4H9, C5H11, and C6H13. The molting hormonal activity of these compounds was measured using cultured integuments prepared from rice stem borers, Chilo suppressalis Walker, in terms of stimulation of incorporation of N:acetyl- [14C]glucosamine. N-t-Butyl-N-3,5-dimethylbenzoyl-N'-acylhydrazines with a hexanoyl or heptanoyl group were about 20-fold higher than that of 20E, whereas N-acyl-N-t-butyl-N'-4-ethylbenzoylhydrazines with a hexanoyl or heptanoyl group were much weaker than 20E. Their larvicidal activity was also measured against rice stem borers. The former series of compounds were much more active than the other series as well as 20E. Thus, the benzoyl moiety of dibenzoylhydrazines, which is bound to the secondary nitrogen atom (-NH-), is replaceable by aliphatic acyl groups without, greatly, affecting the biological activities.
- Shimizu, Bun-Ichi,Nakagawa, Yoshiaki,Hattori, Kazunari,Nishimura, Keiichiro,Kurihara, Norio,Ueno, Tamio
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p. 638 - 642
(2007/10/03)
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- Synthesis of 2,5-Dioxygenated Pyrazine 4-Oxides: Total Synthesis of a New Inhibitor of Superoxide Anion Generation, OPC-15161
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The total synthesis of OPC-15161 1, a new inhibitor of superoxide anion generation, is described in full.Three approaches, routes A-C, have been investigated focusing on the pivotal structure 2,5-dioxygenated pyrazine 4-oxide.Among them, route A led to the total synthesis of 1.That is, the key precursor, 5-hydroxypyrazin-2(1H)-one 4-oxide 7 has been prepared from tryptophan methyl ester 2 in three steps, and direct methylation of the 5-hydroxy group of 7 or three-step methylation via the 2-O-Boc derivative 10 afforded 1 in 9.9-10.6percent overall yields.
- Kita, Yasuyuki,Akai, Shuji,Fujioka, Hiromichi,Tamura, Yasumitsu,Tone, Hitoshi,Taniguchi, Youichi
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p. 875 - 884
(2007/10/02)
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- Synthesis and biological activity of 19-azasqualene 2,3-epoxide as inhibitor of 2,3-oxidosqualene cyclase
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19-Azasqualene 2,3-epoxide and its N-oxide, high-energy intermediate analogue inhibitors of 2,3-oxidosqualene (SO) cyclase were obtained by total synthesis.These compounds were designed to mimic the C-20 carbonium ion precursor of lanosterol formed during SO cyclization.The synthesis involved the preparation of C22squalenoid aldehyde epoxide through a new procedure and the reconstruction of the squalenoid chain bearing a nitrogen at C-19 (pro C-20). 19-Azasqulene 2,3-epoxide was active on SO cyclase from rat and pig liver with an IC50 of 1.5 μM in pig. while in SO cyc lases of yeast (S cerevisiae and C albicans) microsomes it was 20-30-fold less active.It was inactive on squalene epoxidase from rat and pig liver at the highest concentrations tested (100 μM). 2,3-oxidosqualane cyclase inhibitors/ epoxy azasqualanes/ hypocholesterolemic/ antifungals
- Ceruti, M.,Rocco, F.,Viola, G.,Balliano, G.,Grosa, G.,et al.
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p. 675 - 682
(2007/10/02)
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