17746-05-3Relevant articles and documents
Optimization of benzoxazinones as natural herbicide models by lipophilicity enhancement
Macias, Francisco A.,Marin, David,Oliveros-Bastidas, Alberto,Molinillo, Jose M. G.
, p. 9357 - 9365 (2006)
Benzoxazinones are plant allelochemicals well-known for their phytotoxic activity and for taking part in the defense strategies of Gramineae, Ranunculaceae, and Scrophulariceae plants. These properties, in addition to the recently optimized methodologies for their large-scale isolation and synthesis, have made some derivatives of natural products, 2,4-dihydroxy-(2H)-1,4- benzoxazin-3-(4H)-one (DIBOA) and its 7-methoxy analogue (DIMBOA), successful templates in the search for natural herbicide models. These new chemicals should be part of integrated methodologies for weed control. In ongoing research about the structure-activity relationships of benzoxazinones and the structural requirements for their phytotoxicity enhancement and after characterization of the optimal structural features, a new generation of chemicals with enhanced lipophilicity was developed. They were tested on selected standard target species and weeds in the search for the optimal aqueous solubility-lipophilicity rate for phytotoxicity. This physical parameter is known to be crucial in modern drug and agrochemical design strategies. The new compounds obtained in this way had interesting phytotoxicity profiles, empowering the phytotoxic effect of the starting benzoxazinone template in some cases. Quantitative structure-activity relationships were obtained by bioactivity-molecular parameters correlations. Because optimal lipophilicity values for phytotoxicity vary with the tested plant, these new derivatives constitute a more selective way to take advantage of benzoxazinone phytotoxic capabilities.
Enantioselective inhibition of squalene synthase by aziridine analogues of presqualene diphosphate
Koohang, Ali,Bailey, Jessica L.,Coates, Robert M.,Erickson, Hans K.,Owen, David,Poulter, C. Dale
, p. 4769 - 4777 (2010)
(Figure Presented) Squalene synthase catalyzes the conversion of two molecules of (E,E)-farnesyl diphosphate to squalene via the cyclopropylcarbinyl intermediate, presqualene diphosphate (PSPP). Since this novel reaction constitutes the first committed step in sterol biosynthesis, there has been considerable interest and research on the stereochemistry and mechanism of the process and in the design of selective inhibitors of the enzyme. This paper reports the synthesis and characterization of five racemic and two enantiopure aziridine analogues of PSPP and the evaluation of their potencies as inhibitors of recombinant yeast squalene synthase. The key aziridine-2-methanol intermediates (6-OH, 7-OH, and 8-OH) were obtained by N-alkylations or by an N-acylation-reduction sequence of (±)-, (2R,3S)-, and (2S,3R)-2,3-aziridinofarnesol (9-OH) protected as tert-butyldimethylsilyl ethers. SN2 displacements of the corresponding methanesulfonates with pyrophosphate and methanediphosphonate anions afforded aziridine 2-methyl diphosphates and methanediphosphonates bearing N-undecyl, N-bishomogeranyl, and N-(α-methylene)bishomogeranyl substituents as mimics for the 2,6,10-trimethylundeca-2,5,9-trienyl side chain of PSPP. The 2R,3S diphosphate enantiomer bearing the N-bishomogeranyl substituent corresponding in absolute stereochemistry to PSPP proved to be the most potent inhibitor (IC50 1.17 ± 0.08 M in the presence of inorganic pyrophosphate), a value 4-fold less than that of its 2S,3R stereoisomer. The other aziridine analogues bearing the N-(α-methylene)bishomogeranyl and N-undecyl substituents, and the related methanediphosphonates, exhibited lower affinities for recombinant squalene synthase.
Mild methods to assemble and pattern organic monolayers on hydrogen-terminated Si(111)
Arafat, Samer N.,Dutta, Samrat,Perring, Mathew,Mitchell, Michael,Kenis, Paul J. A.,Bowden, Ned B.
, p. 3198 - 3200 (2005)
Mild methods to assemble well-ordered organic monolayers of olefins on Si(111) using 2,2,6,6-tetramethyl-1-piperidinyloxy and to pattern these monolayers on the micrometer-size scale using soft lithography are reported. The Royal Society of Chemistry 2005.
Synthesis of Long-Chain Alkanoyl Benzenes by an Aluminum(III) Chloride-Catalyzed Destannylative Acylation Reaction
Roemer, Max,Keaveney, Sinead T.,Proschogo, Nicholas
, p. 9007 - 9022 (2021/07/20)
This paper describes the facile synthesis of haloaryl compounds with long-chain alkanoyl substituents by the destannylative acylation of haloaryls bearing tri-n-butyltin (Bu3Sn) substituents. The method allows the synthesis of many important synthons for novel functional materials in a highly efficient manner. The halo-tri-n-butyltin benzenes are obtained by the lithium-halogen exchange of commercially available bis-haloarenes and the subsequent reaction with Bu3SnCl. Under typical Friedel-Crafts conditions, i.e., the presence of an acid chloride and AlCl3, the haloaryls are acylated through destannylation. The reactions proceed fast (5 min) at low temperatures and thus are compatible with aromatic halogen substituents. Furthermore, the method is applicable topara-,meta-, andortho-substitution and larger systems, as demonstrated for biphenyls. The generated tin byproducts were efficiently removed by trapping with silica/KF filtration, and most long-chain haloaryls were obtained chromatography-free. Molecular structures of several products were determined by X-ray single-crystal diffraction, and the crystal packing was investigated by mapping Hirshfeld surfaces onto individual molecules. A feasible reaction mechanism for the destannylative acylation reaction is proposed and supported through density functional theory (DFT) calculations. DFT results in combination with NMR-scale control experiments unambiguously demonstrate the importance of the tin substituent as a leaving group, which enables the acylation.
Characterization of the molecular packing, thermotropic phase behaviour and critical micellar concentration of a homologous series of N-acyltaurines (n = 9–18). PXRD, DSC and fluorescence spectroscopic studies
Arul Prakash, Sukanya,Kamlekar, Ravi Kanth
, (2020/06/22)
N-acyltaurines (NATs) are amides of fatty acids that can be structurally related to endocannabinoids. They show interesting physiological and pharmacological properties. We have synthesized a homologous series of NATs with saturated acyl chains (n = 9–18) and investigated their supramolecular structure and thermotropic phase transitions by powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC). The d-spacings obtained from PXRD increase linearly with chain length with an increment of ～0.847 ? per additional CH2 moiety suggesting that NATs adopt a tilted bilayer structure with similar packing in crystal lattice. Results obtained from DSC studies indicate that the endothermic transition temperature (Tt) of NATs showed a gradually increasing trend with increasing acyl chain length. The enthalpy (ΔHt) and entropy (ΔSt) of transition show odd-even alternations with odd-chain compounds having higher values than the even-chain compounds. The critical micellar concentration (CMC) of NATs was determined in water at room temperature by fluorescence spectroscopy by monitoring the spectral changes of 8-anilinonaphthalene-1-sulfonic acid (ANS). The CMCs of NATs were found to decrease with increase in acyl chain length. The present results provide a thermodynamic and structural basis for investigating the interaction of NATs with other membrane lipids and proteins, which in turn can shed light in understanding how they function in vivo (in biological membranes).
Strategic Approach to the Metamorphosis of γ-Lactones to NH γ-Lactams via Reductive Cleavage and C-H Amidation
Jung, Hoi-Yun,Chang, Sukbok,Hong, Sungwoo
supporting information, p. 7099 - 7103 (2019/09/07)
A new approach has elaborated on the conversion of γ-lactones to the corresponding NH γ-lactams that can serve as γ-lactone bioisosteres. This approach consists of reductive C-O cleavage and an Ir-catalyzed C-H amidation, offering a powerful synthetic tool for accessing a wide range of valuable NH γ-lactam building blocks starting from γ-lactones. The synthetic utility was further demonstrated by the late-stage transformation of complex bioactive molecules and the asymmetric transformation.
PYRROLE DERIVATIVES AS ACC INHIBITORS
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Page/Page column 48; 49, (2019/07/19)
Novel pyrrole derivatives of Formula (I) are disclosed; as well as process for their preparation, pharmaceutical compositions comprising them and their use in therapy as inhibitors of Acetyl- CoA carboxylase (ACC).
Mesogenic 3,6-bis(4-hydroxyphenyl)-1,2,4,5-tetrazine alkanoate esters
Fouad, Farid,Khabouchi, Faycal,Nielsen, Alek,Twieg, Robert
, p. 82 - 90 (2019/02/24)
A novel series of 3,6-bis(4-hdroxyphenyl)-1,2,4,5-tetrazine alkanoate esters were synthesized and their mesogenic properties were studied using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). The impact of changing the tail-core linkage from alkyl or alkoxy to ester is profound. Compared to the alkyl or alkoxy linkages, the ester linkage reduced mesogenic properties. Short-tailed compounds are non mesogenic (4a-4e), while long-tailed compounds (4f-4r) exhibit nematic phases. Unlike the alkyl or alkoxy tail series, none of the 18 presented esters in this series exhibits a smectic phase.
Synthesis, antimicrobial activity and in silico studies on thymol esters
Lazarevi?, Jelena,Kolarevi?, Ana,Dordevi?, Aleksandra,Stojanovi?, Gordana,?melcerovi?, Andrija,Ciuffreda, Pierangela,Santaniello, Enzo
, p. 603 - 612 (2017/09/11)
Derivatisation of parent structure in terpenoids often results in enhancement of biological activity of newly obtained compounds. Thymol, a naturally occurring phenol biosynthesized through the terpene pathway, is a well known biocide with strong antimicrobial attributes and diverse therapeutic activities. We have aimed our study on a single modification of phenolic functionality in thymol in order to obtain a small focused library of twenty thymyl esters, ten of which were new compounds. All compounds were involved in in vitro antimicrobial testing. Another important aspect of current study was implementation of in silico calculation of physico-chemical, pharmacokinetic and toxicological properties, which could be helpful by giving an additional guidance in further research.
Structure, supramolecular organization and phase behavior of N-acyl-β-alanines: Structural homologues of mammalian brain constituents N-acylglycine and N-acyl-GABA
Sivaramakrishna,Swamy, Musti J.
, p. 1 - 10 (2016/11/11)
N-Acyl-β-alanines (NABAs) are structural homologues of N-acylglycines (NAGs) and N-acyl-γ-aminobutyric acids (NAGABAs), and achiral isomers of N-acylalanines, which are all present in mammalian brain and other tissues and modulate activity of biological receptors with various functions. In the present study, we synthesized and characterized a homologous series of NABAs bearing saturated acyl chains (n = 8-20) and investigated their supramolecular organization and thermotropic phase behavior. In differential scanning calorimetric (DSC) studies, most of the NABAs gave one or two minor transitions before the main chain-melting phase transition in the dry state as well as upon hydration with water, but gave only a single transition when hydrated with buffer (pH 7.6). Transition enthalpies (ΔHt) and entropies (ΔSt), obtained from the DSC studies showed linear dependence on the chain length in the dry state and upon hydration with buffer, whereas odd-even alteration was observed when hydrated with water. The crystal structures of N-lauroyl-β-alanine (NLBA) and N-myristoyl-β-alanine (NMBA) were solved in monoclinic system in the P21/c space group. Both NLBA and NMBA were packed in tilted bilayers with head-to-head (and tail-to-tail) arrangement with tilt angles of 33.28° and 34.42°, respectively. Strong hydrogen bonding interactions between [sbnd]COOH groups of the molecules from opposite leaflets as well as N[sbnd]H?O hydrogen bonds between the amide groups from adjacent molecules in the same leaflet as well as dispersion interactions between the acyl chains stabilize the bilayer structure. The d-spacings calculated from powder X-ray diffraction studies showed odd-even alteration with odd-chain length compounds exhibiting higher values as compared to the even-chain length ones and the tilt angles calculated from the PXRD data are higher for the even chain NABAs. These observations are relevant to developing structure-activity relationships for these amphiphiles and understand how NABAs differ from their homologues and isomers, namely NAGs, NAGABAs, and N-acylalanines.
