52972-61-9Relevant articles and documents
Bond-specific dissociation following excitation energy transfer for distance constraint determination in the gas phase
Hendricks, Nathan G.,Lareau, Nichole M.,Stow, Sarah M.,McLean, John A.,Julian, Ryan R.
, p. 13363 - 13370 (2014)
Herein, we report chemistry that enables excitation energy transfer (EET) to be accurately measured via action spectroscopy on gaseous ions in an ion trap. It is demonstrated that EET between tryptophan or tyrosine and a disulfide bond leads to excited state, homolytic fragmentation of the disulfide bond. This phenomenon exhibits a tight distance dependence, which is consistent with Dexter exchange transfer. The extent of fragmentation of the disulfide bond can be used to determine the distance between the chromophore and disulfide bond. The chemistry is well suited for the examination of protein structure in the gas phase because native amino acids can serve as the donor/acceptor moieties. Furthermore, both tyrosine and tryptophan exhibit unique action spectra, meaning that the identity of the donating chromophore can be easily determined in addition to the distance between donor/acceptor. Application of the method to the Trpcage miniprotein reveals distance constraints that are consistent with a native-like fold for the +2 charge state in the gas phase. This structure is stabilized by several salt bridges, which have also been observed to be important previously in proteins that retain native-like structures in the gas phase. The ability of this method to measure specific distance constraints, potentially at numerous positions if combined with site-directed mutagenesis, significantly enhances our ability to examine protein structure in the gas phase.
GRAMINE-DERIVED BROMO-ALKALOIDS FROM THE MARINE BRYOZOAN ZOOBOTRYON VERTICILLATUM
Sato, Aiya,Fenical, William
, p. 481 - 484 (1983)
Two new natural products, 2,5,6-tribromo-N-methylgramine (1) and its corresponding sidechain N-oxide, 2, have been isolated from the subtropical marine bryozoan Zoobotryon verticillatum.The structures of these compounds were illustrated by spectral analyses and by chemical synthesis.
MANNICH REACTIONS OF Π-EXCESSIVE HETEROCYLES USING BIS-(DIALKYLAMINO)METHANES AND ALKOXYDIALKYLAMINOMETHANES ACTIVATED WITH ACETYL CHLORIDE OR SULPHUR DIOXIDE
Eyley, Stephen C.,Heaney, Harry,Papageorgiou, George,Wilkins, Robert F.
, p. 2997 - 3000 (1988)
Π-Excessive heterocyles react rapidly with bis(dialkylamino)methanes (aminals) and alkoxydialkylaminomethanes (aminol ethers) in acetonitrile to afford Mannnich bases in good yields when ativated by means of an acidi reagent suh as acetyl chloride or sulphur dioxide: the principal ompound studied was N-methylpyrrole.
Natural Products for Drug Discovery: Discovery of Gramines as Novel Agents against a Plant Virus
Lu, Aidang,Wang, Tienan,Hui, Hao,Wei, Xiaoye,Cui, Weihao,Zhou, Chunlv,Li, Hongyan,Wang, Ziwen,Guo, Jincheng,Ma, Dejun,Wang, Qingmin
, p. 2148 - 2156 (2019/03/08)
Plant viral diseases seriously affect crop yield and quality. The natural product gramine (1) and its simple structural analogues 2-35 were synthesized from indoles, amines, and aldehydes in one step. The antiviral effects of these alkaloids were evaluated systematically. Most of these compounds were found to have higher antiviral effects than commercial ribavirin for the first time. Especially compounds 22, 30, and 31 exhibited significantly higher effects than ningnanmycin, thereby emerging as novel antiviral leads for further optimization. The preliminary implementation indicated that these compounds likely inhibit the assembly of tobacco mosaic virus (TMV) by cross-linking TMV capsid protein. Gramine analogues were also found to have broad-spectrum fungicidal effects. Although gramine has been reported to have influence on germination and development of Erysiphe graminis, these compounds displayed no fungicidal effects against Blumeria graminis f. sp. tritici on wheat in our test. Some of these compounds also exhibited certain insecticidal activities.
Substitution of the Dimethylamino Group in Gramines and One-Pot Cyclization to Tetrahydro-β-carbolines Using a Triazine-Based Activating Agent
Fujita, Hikaru,Nishikawa, Riho,Sasamoto, Ozora,Kitamura, Masanori,Kunishima, Munetaka
, p. 8380 - 8391 (2019/07/08)
A new method for the substitution of 3-[(dimethylamino)methyl]indoles (gramines) with malonate-based nucleophiles was developed using 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) as the activating agent for the dimethylamino group. The reaction was completed in 1.5-6 h at room temperature in the presence of a tert-amine base and lithium salt. CDMT afforded superior results to methyl iodide, a common activating agent for the dimethylamino group in Mannich bases, particularly in the reactions of 1-substituted gramines. The reactivity of the possible intermediates, bis(indol-3-ylmethyl)dimethylammonium salts, was examined to obtain mechanistic insights on the reaction. This substitution method with CDMT enabled the sequential transformation of gramines: substitution with (N-alkylidene)aminomalonates followed by the Pictet-Spengler reaction under acidic conditions afforded 1,2,3,4-tetrahydro-β-carboline derivatives in one pot.
Visible-Light-Mediated α-Oxygenation of 3-(N,N-Dimethylaminomethyl)-Indoles to Aldehydes
Stanek, Filip,Paw?owski, Robert,Mlynarski, Jacek,Stodulski, Maciej
supporting information, p. 6624 - 6628 (2018/10/20)
The visible-light-mediated oxygenation of 3-N,N-(dimethylaminomethyl)-indoles bearing various substituents afforded a series of 3-carbaindole derivatives. Herein we describe the reaction scope, a plausible mechanism and a practical application of this transformation in the formal synthesis of (–)-vincorine is described as well.
Enantiospecific Synthesis of ortho-Substituted Benzylic Boronic Esters by a 1,2-Metalate Rearrangement/1,3-Borotropic Shift Sequence
Aichhorn, Stefan,Bigler, Raphael,Myers, Eddie L.,Aggarwal, Varinder K.
supporting information, p. 9519 - 9522 (2017/07/25)
Coupling reactions between benzylamines and boronic esters have been investigated. ortho-Lithiated benzylamines react with boronic esters and a N-activator to afford ortho-substituted benzylic boronic esters with formal 1,1′-benzylidene insertion into the C-B bond. The reaction occurs by a SN2′ elimination and 1,2-metalate rearrangement of the N-activated boronate complex to afford a dearomatized intermediate, which undergoes a Lewis-acid catalyzed 1,3-borotropic shift to afford the boronic ester products in high yield and with excellent enantiospecificity. The use of enantioenriched α-substituted benzylamines gave the corresponding secondary boronic esters with high ee.
Imidazo[4,5-a]quinindolines as highly effective antibacterial agents
Pordel, Mehdi,Ramezani, Shirin,Jajarmi, Maryam,Sokhanvar, Mina
, p. 106 - 110 (2016/02/18)
Resistance to antimicrobial agents is a concern that exists globally and has a considerable impact on human and animal health, so that the discovery of new antibacterial compounds has become increasingly more important in combating infectious disease. In this paper, imidazo[4,5-a]quinindolines are introduced as new antibacterial agents against Gram-positive and Gram-negative bacteria. These pentacyclic compounds are synthesized by the reaction of N-alkyl-5-nitrobenzimidazoles with 2-(1-alkyl-1H-3-indolyl)acetonitrile under basic conditions in excellent yields. The structures of newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, and mass spectral data. The antibacterial activities of the synthesized compounds were screened against standard strains of two Gram-positive and two Gram-negative bacteria using the broth microdilution method. Most of the compounds studied showed promising activities against both types of bacteria.
Pyrazolo[4,3-a]quinindoline as a new highly fluorescent heterocyclic system: Design, synthesis, spectroscopic characterization and DFT calculations
Alikhani, Elaheh,Pordel, Mehdi,Daghigh, Leila Rezaei
, p. 1484 - 1490 (2015/02/19)
(Chemical Equation Presented) After obtaining the desired precursors in several reactions, new N-alkyl-substituted heterocyclic system pyrazolo[4,3-a]quinindolines (pyrazolo[4,3-f]-indolo[2,3-b]quinolines) were synthesized by one-pot reaction of 1-alkyl-5-nitro-1H-indazole with 2-(1-alkyl-1H-3-indolyl)acetonitrile in MeOH/KOH solution via the nucleophilic substitution of hydrogen in excellent yields. Spectral (UV-Vis, FT-IR, NMR and fluorescence) and analytical data allowed the structures of the synthesized compounds to be established. The values of absorption and fluorescence maxima, extinction coefficients and fluorescence quantum yield of these new heterocyclic fluorophores were obtained and they show highlighting interesting photophysical properties. Density functional theory (DFT) calculations of one structure by using the B3LYP hybrid functional and the 6-311 + G(d,p) basis set were performed to provide the optimized geometry, relevant frontier orbitals and the prediction of 1H NMR chemical shifts. Calculated electronic absorption spectrum of one structure was also obtained by time-dependent density functional theory (TD-DFT) method. Solvatochromic properties of these dyes have been discussed and the results showed that the absorption and emission bands in polar solvents undergo a modest red shift.
Synthesis and preliminary cytotoxicity studies of achiral indolyl-substituted titanocenes
Hogan, Megan,Gleeson, Brendan,Tacke, Matthias
experimental part, p. 1032 - 1040 (2010/04/25)
From the reaction of various 6-indolylfulvenes (la-f) with Super Hydride (LiBEt3H), followed by transmetalation with titanium tetrachloride (TiCl4), six indolyl-substituted titanocenes, bis[( 1 -methylindol-2-yl)cyclopentadienyl]titanium(IV) dichloride (3a), bis[( 1 -methyl-5-methoxyindol-2-yl)cyclopentadienyl]titanium(IV) dichloride (3b), a dihydrochloride derivative of bis[(l-methyl3-dimethylaminomethylindol-2-yl) cyclopentadienyl]titanium(IV) dichloride (3c), bis[(l-methylindol-3yl) cyclopentadienyl]titanium(IV) dichloride (3d), bis[(l-methyl-5-methoxyindol-3- yl)cyclopentadienyl]titanium(IV) dichloride (3e), and bis[(l-methylmethoxyindol- 3-yl)cyclopentadienyl]titanium(IV) dichloride (3f), were obtained. The six titanocenes 3a-f were tested for their cytotoxicity through MTT-based in vitro tests on CAKI-I cell lines in order to determine their IC50 values. Titanocenes 3a-f were found to have IC50 values of 47 (±9), 15 (±2), 8.2 (±1.9), 21 (±5), 11 (±1), and 170 (±40) μM, respectively.
