- Characterization of a carbon-carbon hydrolase from Mycobacterium tuberculosis involved in cholesterol metabolism
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In the recently identified cholesterol catabolic pathway of Mycobacterium tuberculosis, 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase (HsaD) is proposed to catalyze the hydrolysis of a carbon-carbon bond in 4,5-9,10-diseco-3-hydroxy-5,9,17-tri-oxoandrosta-1 (10),2-diene-4-oic acid (DSHA), the cholesterol meta-cleavage product (MCP) and has been implicated in the intracellular survival of the pathogen. Herein, purified HsaD demonstrated 4-33 times higher specificity for DSHA (kcat/Km = 3.3 ± 0.3 × 104 M-1 s-1) than for the biphenyl MCP 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid (HOPDA) and the synthetic analogue 8-(2-chlorophenyl)-2-hydroxy-5-methyl-6-oxoocta-2, 4-dienoic acid (HOPODA), respectively. The S114A variant of HsaD, in which the active site serine was substituted with alanine, was catalytically impaired and bound DSHA with a Kd of 51 ± 2 μM. The S114A·DSHA species absorbed maximally at 456 nm, 60 nm red-shifted versus the DSHA enolate. Crystal structures of the variant in complex with HOPDA, HOPODA, or DSHA to 1.8 -1.9 A indicate that this shift is due to the enzyme-induced strain of the enolate. These data indicate that the catalytic serine catalyzes tautomerization. A second role for this residue is suggested by a solvent molecule whose position in all structures is consistent with its activation by the serine for the nucleophilic attack of the substrate. Finally, the α-helical lid covering the active site displayed a ligand-dependent conformational change involving differences in side chain carbon positions of up to 6.7 A, supporting a two-conformation enzymatic mechanism. Overall, these results provide novel insights into the determinants of specificity in a mycobacterial cholesterol-degrading enzyme as well as into the mechanism of MCP hydrolases.
- Lack, Nathan A.,Yam, Katherine C.,Lowe, Edward E.,Horsman, Geoff P.,Owen, Robin L.,Sim, Edith,Eltis, Lindsay D.
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- Method for synthesizing phenylpropionic acid compounds through heterogeneous palladium metal catalysis
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The invention discloses a method for synthesizing phenylpropionic acid compounds by heterogeneous catalysis. The method comprises the following steps: sequentially adding Pd@POL, toluene, styrene, formic acid and acetic anhydride into a reaction flask, stirring the reaction mixture at 80 DEG C to react, cooling the reaction solution to room temperature after the reaction is finished, diluting with dichloromethane, and transferring the solution into a separating funnel, washing with a sodium hydroxide solution, acidifying the water layer with a hydrochloric acid aqueous solution, extracting with dichloromethane, merging organic phases, drying with anhydrous sodium sulfate, and carrying out vacuum concentration to obtain the phenylpropionic acid compound. The method can remove heavy metal residues, is green and environment-friendly, is simple to operate and easy to implement, and the prepared phenylpropionic acid compound has a good application prospect.
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Paragraph 0070-0076
(2021/04/21)
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- Discovery of Novel UDP- N-Acetylglucosamine Acyltransferase (LpxA) Inhibitors with Activity against Pseudomonas aeruginosa
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This study describes a novel series of UDP-N-acetylglucosamine acyltransferase (LpxA) inhibitors that was identified through affinity-mediated selection from a DNA-encoded compound library. The original hit was a selective inhibitor of Pseudomonas aeruginosa LpxA with no activity against Escherichia coli LpxA. The biochemical potency of the series was optimized through an X-ray crystallography-supported medicinal chemistry program, resulting in compounds with nanomolar activity against P. aeruginosa LpxA (best half-maximal inhibitory concentration (IC50) 20 μM and MIC > 128 μg/mL). The mode of action of analogues was confirmed through genetic analyses. As expected, compounds were active against multidrug-resistant isolates. Further optimization of pharmacokinetics is needed before efficacy studies in mouse infection models can be attempted. To our knowledge, this is the first reported LpxA inhibitor series with selective activity against P. aeruginosa.
- Andersen, Ole A.,Barbeau, Olivier R.,Barker, John,Cain, Ricky,Centrella, Paolo A.,Clark, Matthew A.,Compper, Christel,Corbett, David,Cuozzo, John W.,Dejob, Magali,Dejonge, Boudewijn L. M.,Deng, Boer,Dickie, Anthony P.,Dorali, Alain,Etheridge, Donnya,Evans, Sian,Faulkner, Adele,Gadouleau, Elise,Gorman, Timothy,Haase, Denes,Holbrow-Wilshaw, Maisie,Hunt, Avery,Keefe, Anthony D.,Krulle, Thomas,Li, Xianfu,Lumley, Christopher,Mertins, Barbara,Napier, Spencer,Odedra, Rajesh,Papadopoulos, Kostas,Parkes, Alastair L.,Roumpelakis, Vasileios,Ryan, M. Dominic,Sanzone, Angelo,Sigel, Eric A.,Southey, Michelle,Soutter, Holly T.,Spear, Kate,Stein, Daniel B.,Thommes, Pia,Trimby, Emily,Troast, Dawn M.,Williams, Jennifer,Zahn, Michael,Zhang, Ying
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p. 14377 - 14425
(2021/10/25)
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- Harnessing Applied Potential: Selective β-Hydrocarboxylation of Substituted Olefins
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The construction of carboxylic acid compounds in a selective fashion from low value materials such as alkenes remains a long-standing challenge to synthetic chemists. In particular, β-addition to styrenes is underdeveloped. Herein we report a new electrosynthetic approach to the selective hydrocarboxylation of alkenes that overcomes the limitations of current transition metal and photochemical approaches. The reported method allows unprecedented direct access to carboxylic acids derived from β,β-trisubstituted alkenes, in a highly regioselective manner.
- Alkayal, Anas,Buckley, Benjamin R.,Malkov, Andrei V.,Montanaro, Stephanie,Tabas, Volodymyr,Wright, Iain A.
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supporting information
(2020/02/13)
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- Cyclohexyl-Fused, Spirobiindane-Derived, Phosphine-Catalyzed Synthesis of Tricyclic ?3-Lactams and Kinetic Resolution of ?3-Substituted Allenoates
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A C2-symmetric chiral phosphine catalyst, NUSIOC-Phos, which can be easily derived from cyclohexyl-fused spirobiindane, was introduced. A highly enantioselective domino process involving pyrrolidine-2,3-diones and γ-substituted allenoates catalyzed by NUSIOC-Phos has been disclosed. Diastereospecific tricyclic γ-lactams containing five contiguous stereogenic centers were obtained in high yields and with nearly perfect enantioselectivities. A kinetic resolution process of racemic γ-substituted allenoates was developed for the generation of optically enriched chiral allenoates.
- Wu, Mingyue,Han, Zhaobin,Li, Kaizhi,Wu, Ji'En,Ding, Kuiling,Lu, Yixin
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supporting information
p. 16362 - 16373
(2019/10/16)
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- Regioselectivity inversion tuned by iron(iii) salts in palladium-catalyzed carbonylations
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Impactful regioselectivity control is crucial for cost-effective chemical synthesis. By using cheap and abundant iron(iii) salts, the hydroxycarbonylations of both aromatic and aliphatic alkenes were significantly enhanced in both reactivity and selectivity (iso/n or n/iso up to >99:1). Moreover, Pd-catalyzed carbonylation selectivity can be switched from branched to linear by using different Fe(iii) salts. In addition, similar results were obtained for the carbonylation of secondary alcohols.
- Huang, Zijun,Cheng, Yazhe,Chen, Xipeng,Wang, Hui-Fang,Du, Chen-Xia,Li, Yuehui
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supporting information
p. 3967 - 3970
(2018/04/23)
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- Synthesis of N-Substituted Condensed Tetrahydropyridine-Based Enaminones via Palladium-Catalyzed Intramolecular C–N Cross-coupling
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A number of β-enaminones with secondary amino group (alkyl, cyclopropyl, and aryl) were prepared from corresponding β-diketones. Two general protocols for their palladium-catalyzed intramolecular C–N cross-coupling were established to give corresponding N-substituted condensed tetrahydropyridines in good yields. The methodology is applicable for a wide variety of structural motifs. The work also extends the applicability of novel, recently established, palladium precatalysts to new substrates.
- Dou?ová, Hana,R??i?ková, Zdeňka,?im?nek, Petr
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supporting information
p. 670 - 684
(2018/01/22)
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- A Ligand-Directed Catalytic Regioselective Hydrocarboxylation of Aryl Olefins with Pd and Formic Acid
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An effective Pd-catalyzed hydrocarboxylation of aryl olefins with Ac2O and formic acid is described. A variety of 2- and 3-arylpropanoic acids can be regioselectively formed by the judicious choice of ligand without the use of toxic CO gas.
- Liu, Wei,Ren, Wenlong,Li, Jingfu,Shi, Yuan,Chang, Wenju,Shi, Yian
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supporting information
p. 1748 - 1751
(2017/04/11)
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- An intramolecular C-N cross-coupling of β-enaminones: A simple and efficient way to precursors of some alkaloids of Galipea officinalis
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2-Aroylmethylidene-1,2,3,4-tetrahydroquinolines with the appropriate substituents can be suitable precursors for the synthesis of alkaloids from Galipea officinalis (cuspareine, galipeine, galipinine, angustureine). However, only two, rather low-yielding procedures for their synthesis are described in the literature. We have developed a simple and efficient protocol for an intramolecular, palladium or copper-catalysed amination of both chloro- and bromo-substituted 3-amino-1,5-diphenylpent-2-en-1-ones leading to the above-mentioned tetrahydroquinoline moiety. The methodology is superior to the methods published to date.
- Douov, Hana,Hork, Radim,Ruikov, Zdeka,imunek, Petr
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supporting information
p. 884 - 892
(2015/08/24)
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- Simultaneous control of regioselectivity and enantioselectivity in the hydroxycarbonylation and methoxycarbonylation of vinyl arenes
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Using a family of novel mononuclear and dinuclear palladium complexes of phanephos ligands, the simultaneous control of regioselectivity and enantioselectivity in the hydroxycarbonylation and alkoxycarbonylation of styrene derivatives has been realised for the first time. The Royal Society of Chemistry 2013.
- Konrad, Tina M.,Durrani, Jamie T.,Cobley, Christopher J.,Clarke, Matthew L.
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supporting information
p. 3306 - 3308
(2013/06/05)
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- Selective bromination of 4-chloro-1-indanone and synthesis of (4-chloro-2, 3-dihydro-1H-indene-2-yl)methanamine
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The synthesis of 4-chloro-1-indanone in four steps from 2-chlorobenzaldehyde was investigated. Bromination of this compound under various conditions occurred in the cyclopentanone ring, producing mono- and dibromo derivatives. Cyanation of 2-bromo-4-chlor
- Jasouri,Khalafy,Badali,Piltan
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experimental part
p. 83 - 87
(2011/06/09)
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- Chemoenzymatic synthesis of the calcimimetics (+)-NPS R-568 via asymmetric reductive acylation of ketoxime intermediate
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A practical and efficient procedure for the synthesis of a potent calcimimetic (+)-NPS R-568 was developed. This procedure includes as the key step the asymmetric reductive acylation of a ketoxime intermediate catalyzed by a Pd nanocatalyst and a lipase i
- Han, Kiwon,Kim, Yunwoong,Park, Jaiwook,Kim, Mahn-Joo
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experimental part
p. 3536 - 3537
(2010/08/07)
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- THERAPEUTIC FLUOROETHYLCYANO GUANIDINES
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Disclosed herein is compound having a formula as described herein. Therapeutic methods, compositions, and medicaments related thereto are also disclosed.
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Page/Page column 14; 18
(2008/12/04)
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- Regiospecific solvent-free transfer hydrogenation of α,β-unsaturated carbonyl compounds catalyzed by a cationic ruthenium(II) compound
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[(PPh3)2Ru(CH3CN)3Cl][BPh4] has been found to catalyze the selective reduction of double bonds in α,β-unsaturated ketones with high conversions when formic acid is the hydrogen donor.
- Naskar, Sipra,Bhattacharjee, Manish
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p. 465 - 467
(2008/02/03)
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- Aromatic chlorination of ω-phenylalkylamines and ω- phenylalkylamides in carbon tetrachloride and α,α,α- trifluorotoluene
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The aromatic halogenation of simple alkylbenzenes with chlorine proceeds smoothly in acetic acid but is much less efficient in less polar solvents. By contrast chlorination of ω-phenylalkylamines, such as 3-phenylpropylamine, occurs readily in either acetic acid, carbon tetrachloride or α,α,α-trifluorotoluene, and in the latter solvents gives high proportions of ortho-chlorinated products. These effects are attributable to the involvement of N-chloroamines as reaction intermediates, with intramolecular delivery of the chlorine electrophile. ω-Phenylalkylamides, such as 3-phenylpropionamide, also easily undergo aromatic chlorination in carbon tetrachloride and α,α,α-trifluorotoluene. These reactions generally show a first-order dependence on the substrate concentration, but not on the amount of chlorine. With carbon tetrachloride, very similar reaction rates are observed with chlorine concentrations ranging from 0.1-1.5 M. In α,α,α-trifluorotoluene, the rates reach a plateau at a chlorine concentration of approximately 0.2 M. These features indicate that the reactions proceed via the formation of intermediates which evidence suggests may be the corresponding O-chloroimidates. Irrespective of the mechanistic details, the reactions are remarkably rapid, being faster than analogous reactions in acetic acid and three to four orders of magnitude more rapid than reactions of simple alkylbenzenes in carbon tetrachloride. Therefore, chlorination of the amines and amides may be accomplished without the need for highly polar solvents, added catalysts or large excesses of chlorine, which are often employed for electrophilic aromatic substitutions. Although the use of carbon tetrachloride is becoming increasingly impractical due to environmental concerns, the trifluorotoluene is a suitable alternative. The Royal Society of Chemistry 2006.
- O'Connell, Jenny L.,Simpson, Jamie S.,Dumanski, Paul G.,Simpson, Gregory W.,Easton, Christopher J.
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p. 2716 - 2723
(2008/02/08)
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- Samarium diiodide reduction of cinnamic acids
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The method for measuring SmI2 reduction rates is expanded to a wider range of organic compounds by using not only GC or GC/MS, but also HPLC as the detecting tool. The reduced substrates are not only confined to water insoluble compounds or low boiling compounds only. Water soluble cinnamic acid derivatives of high boiling points are chosen for this application. The absolute rate constants of SmI2 reduction of cinnamic acid in the presence of hexamethyl phosphoramide or t-butanol is considered as a suitable proton source in this reaction. The rates are dependent on substrates and additives as: Rate · [t-BuOH][Cinnamic acid] and Rate · [HMPA][Cinnamic acid] The reduction rates of α-methylcinnamic acid, 2-methylcinnamic acid, 4-methylcinnamic acid, 2-methoxycinnamic acid, 3-methoxycinnamic acid, 4-methoxycinnamic acid, 2-hydroxycinnamic acid, 3-hydroxycinnamic acid, 4-hydroxycinnamic acid, 2-chlorocinnamic acid, 3-chlorocinnamic acid, 4-chlorocinnamic acid were carefully measured to study the substituent effect.
- Lin, Tzuen-Yeuan,Fuh, Ming-Ren,Tsau, Chi-Yu
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p. 917 - 921
(2007/10/03)
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- Transition metal compound, ligand system, catalyst system and its use for the polymerization of olefins
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Ligand systems containing indenyl structures, transition metal compounds of the metallocene type and catalyst systems comprising such transition metal compounds are described. The novel transition metal compounds can be used in the polymerization of olefi
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- Simple, safe, large scale synthesis of 5-arylmethyl-2,2-dimethyl-1,3-dioxane-4,6-diones and 3-aryl-propanoic acids
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Reaction of aryl aldehydes with Meldrum's acid 2 in the presence of formic acid and triethylamine with 5-arylmethyl Meldrum's acid derivatives 4 at room temperature, whereas at 80-100°C 3-arylpropanoic acids 5 are formed.
- Toth,Kover
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p. 3067 - 3074
(2007/10/03)
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- Phenyl or bicyclo-alkenylfluoro amide pesticides
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Compound of the formula (I): or a salt thereof, wherein Q1 is a phenyl ring or a fused bicyclic ring system containing 9 or 10 ring carbon atoms at least one ring being aromatic, or Q1 is a dihalovinyl group; Q is an alkyl chain containing 1 to 12 carbon atoms and optionally containing one or two oxygen atoms and/or an unsaturated group --CR7 =CR8 --, or --C=C--, wherein R7 and R8 are selected from hydrogen or halo; a is 0 or 1; b is 0 or 1; the sum of a and b is 0 or 1; R2, R3, R4, R5 and R6 are the same or different, and are independently selected from hydrogen, halo and C1-4 alkyl; R1 is selected from hydrogen and C1-6 hydrocarbyl optionally substituted by dioxalanyl, halo, cyano, trifluoromethyl, trifluoromethylthio or C1-6 alkoxy are disclosed which have pesticidal activity. Pesticidal formulations containing the compounds of the formula (I), their use in the control of pests and methods for their preparation are also disclosed.
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- SYNTHESE TOTALE DE STEROIDES A CYCLE C AROMATIQUE
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The ring-C aromatic analogue 4 of 4-androstene 3,17-dione and its 11 hydroxylated(methoxylated) derivatives 20a(b) were prepared by a practical synthetic route.The key steps of the sequence are achieved in superacid: the cyclisation of diarylethane 5a to phenanthrenone 17, and the hydroxylation by hydrogenperoxide of ketone 4 to phenol 20a.
- Berrier, C.,Gesson, J. P.,Jacquesy, J. C.,Renoux, A.
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p. 4973 - 4980
(2007/10/02)
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- Pharmaceutical compositions and method of inhibiting phenylethanolamine N-methyltransferase
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Pharmaceutical compositions and methods of inhibiting phenylethanolamine N-methyltransferase using 2-indanamine compounds having 4 and/or 5 substituents.
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