- Impact of N-substituents on crystal packing of N-alkyl-N′-tosylpiperazines and development of new polymorph of tosylbis(2-(tosyloxy)ethyl)amine: Synthesis, DFT, photophysical, cytotoxic property
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Diethanol amine (DEA) was selected as a lead compound to prepare N-tosyldiethanol amine 1, N-tosylbis(2-(tosyloxy)ethyl)amine 2 and disubstituted piperazines ca N-alkyl-N′-tosylpiperazines 3–5 in high yield. The new compounds were characterized by using relevant techniques viz. MS, IR, 1H, 13C, DEPT 135 NMR, UV–vis. absorption and fluorescence spectral studies. Single crystal X-ray diffraction technique was used to detect a new polymorphic form of 2 and to measure the influence of various N-substituents on the association of molecules of 3–5 in the solid state. Evidently, the introduction of N-cyclohexyl substituent in 3 successfully switches off all the synthons ca CH…O and CH…N seen in compound 4 and 5. Compounds 4 and 5 holding N-furfuryl and N-benzyl substituents, respectively, adopt other packing strategies based on CH…O, CH…N (4) and CH…O (5) interactions. The antitumor activity of 1–5 was evaluated in vitro against Hep 3B and IMR 32 by the MTT assay and the results were compared with cisplatin. Remarkably, some compounds were found extremely active against both the cell lines and proved to be more potent as cytotoxic agents than cisplatin. Density functional theory and molecular docking studies have been performed to rationalize the experimental results.
- Kadu, Rahul,Savani, Chirag,Roy, Hetal,Soni,Singh, Atresh Kumar,Vennapu, Dushyanth R.,Singh, Vinay K.
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- Transition metal- And catalyst-free one-pot green method for the synthesis of: N -sulfonyl amidines via direct reaction of sulfonyl azides with amines
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In this report, a green synthesis of N-sulfonyl amidines via the direct reaction of tertiary or secondary amines with sulfonyl azides is described. Transition metal- and catalyst-free conditions were used for the synthesis of biologically important N-sulfonyl amidines. Further studies showed that the reaction proceeded via in situ aerobic oxidation of amines under reflux conditions.
- Aoyama, Hiroshi,Kaboudin, Babak,Kazemi, Foad,Torabi, Saeed
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p. 26701 - 26708
(2020/08/19)
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- NOVEL CYTOTOXIC AGENTS AND CONJUGATES THEREOF
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Provided herein are novel maytansinoid compounds of general formula I. Also provided herein are conjugates comprising the compounds linked to a binding protein via a linker, and conjugating reagents comprising the compounds attached via a linker to at least one functional group capable of reacting with a binding protein. Also provided herein are pharmaceutical compositions comprising the compounds and conjugates, therapeutic methods and uses involving the compounds and conjugates, for example in cancer therapy, and novel synthetic processes.
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Page/Page column 97
(2018/04/13)
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- CONJUGATES AND CONJUGATING REAGENTS COMPRISING A LINKER THAT INCLUDES AT LEAST TWO (-CH2-CH2-0-) UNITS IN A RING
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A conjugate comprising a protein or peptide conjugated to a therapeutic, diagnostic or labelling agent via a linker, characterised in that the linker includes at least two ~(CH2-CH2- 0-)~ units within a ring, said ring being attached via a single tethering atom within the ring to the rest of the linker, or said ring being attached via two or more tethering atoms within the ring to the rest of the linker at a single point.
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Page/Page column 44
(2017/11/16)
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- Synthesis, biological evaluation and study of the effect of various N-substituents on the thermal stabilities of some new diethanolamine derivatives
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Diethanolamine and its derivatives are of considerable interest in medicinal and other industrial products. A series of new diethanolamine derivatives has been synthesized and characterized by 1H NMR, 13C NMR, FTIR and mass spectrometry. All synthesized compounds have been tested for their in vitro antibacterial activity against pathogenic microorganisms Escherichia coli, Staphylococcus aureus, Micrococcus luteus, Pseudomonas aeruginosa, Bacillus subtilis, Pasteurrella mutocida, Rhizopus oryzae and Salmonella typhi. Among the tested compounds, compounds 2a, 2b, 2c, 3a and 4b have been found to be most potent members, which inhibited most of the pathogens used in the assay. Diethanolamine must posses tosyl or trifluoro groups in order to have good antimicrobial activities. All synthesized derivatives exhibited average FRAP activity and considerably good metal chelating activity and compound 2c showed excellent ABTS radical scavanging among all tested derivatives. Thermal stability and the effect of various N-protected groups on the thermal stability and degradation of selected diethanolamine derivatives (free flowing oils at room temperature and solid derivative 2a) has been studied by TGA and DSC analysis.
- Yar, Muhammad,Mushtaq, Nafeesa,Afzal, Sadia,Khan, Abdul Samad,Khan, Islam Ullah,Akhter, Muhammad Nadeem,Zareen, Seema,Shahzad, Sohail Anjum,Khan, Zulfiqar Ali,Raza Naqvi, Syed Ali,Mahmood, Nasir,Tahir, Lubna,Saleem, Muhammad
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p. 7297 - 7304
(2013/08/23)
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- The stereochemical course of bromoetherification of enynes
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Enynes undergo stereoselective syn intramolecular bromoetherification; the stereochemical course of the reaction was elucidated by X-ray crystallographic studies and by stereospecific synthesis of authentic bromoallenes. The Royal Society of Chemistry.
- Christopher Braddock,Bhuva, Roshni,Perez-Fuertes, Yolanda,Pouwer, Rebecca,Roberts, Craig A.,Ruggiero, Andrea,Stokes, Elaine S. E.,White, Andrew J. P.
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p. 1419 - 1421
(2008/12/21)
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- Chelate ring sequence effects on thermodynamic, kinetic and electron-transfer properties of copper(II/I) systems involving macrocyclic lisands with S4 and NS3 donor sets
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The kinetic behavior of electron-transfer reactions involving several copper(II/I) complexes has previously been attributed to a dual-pathway "square scheme" mechanism in which changes in the coordination geometry occur sequentially, rather than concertedly, with the electron-transfer step. In the case of 14-membered macrocyclic quadridentate ligand complexes studied to date, the major geometric change appears to be the inversion of two coordinated donor atoms during the overall electron-transfer process. However, the relative importance of these two inversions has been a matter of speculation. In the current investigation, a comparison is made of Cu(II/I) systems involving two pairs of ligands with S4 and NS3 donor sets: 1,4,8,11-tetrathiacyclotctradecane ([14]aneS4-a); 1,4,7,11-tetrathiacyclotetradecane ([14]aneS4-b); 1,4,8-trithia-11-azacyclotetradecane ([14]aneNS3-fl); and 1,7,11-trithia-4-azacyclotetradecane ([14]aneNS3-b). In each pair of ligands, isomer a has the common chelate ring size sequence 5,6,5,6 while isomer b has the sequence 5,5,6,6. A crystal structure for [CuII([14] aneNS3-&)(H2O)](ClO4)2 demonstrates that, when coordinated to Cu(II), the b isomers stabilize the relatively rare ligand conformation designated as conformer II in which one donor atom is oriented opposite to the other three relative to the plane of the macrocycle. This eliminates one of the donor atom inversion steps which normally occurs during Cu(II/I) electron transfer. The copper complexes formed with these a and b isomers are examined in terms of (i) their CuIIL and CuIL stability constants, (ii) their CuIIL formation and dissociation rate constants, (iii) their CuII/IL redox potentials and (iv) their apparent electron self-exchange rate constants. Of the two donor atom inversions which occur in the case of the a-isomer complexes, the specific donor atom inversion which is common to the b-isomer complexes is judged to exhibit the larger energy barrier. Thus, it is presumed to represent the rate-limiting process responsible for the onset of "gated" electron transfer in previous studies on a-isomer complexes. The Royal Society of Chemistry 2003.
- Galijasevic, Semira,Krylova, Ksenia,Koenigbauer, Michael J.,Jaeger, Gregory S.,Bushendorf, Jeffery D.,Heeg, Mary Jane,Ochrymowycz, Leo A.,Taschner, Michael J.,Rorabacher, David B.
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p. 1577 - 1586
(2007/10/03)
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- Concise synthesis of azacycloundecenes using ring-closing metathesis (RCM)
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Azacycloundecenes, which are key intermediates in the synthesis of derivatives of the marine alkaloid manzamine C, are conveniently prepared using ring-closing olefin metathesis (RCM). The Royal Society of Chemistry 2000.
- Arisawa, Mitsuhiro,Kato, Chiaki,Kaneko, Hiroaki,Nishida, Atsushi,Nakagawa, Masako
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p. 1873 - 1876
(2007/10/03)
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- Synthesis and antinociceptive activity of ring substituted N-[(2-phenyl-2-hydroxy)ethyl]-4-phenyl-4-carboethoxypiperidines
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A series of phenyl substituted N-[(2-phenyl-2-hydroxy)ethyl]-4-phenyl-4-carboethoxylpiperidine were synthesized and their antinociceptive activity tested in mice and compared with morphine sulphate. All compounds demonstrated antinociceptive activity in both the hot plate and the writhing tests. The studies showed that the antinociceptive activity is dependable on both the nature and the position of the substituent on the phenyl ring. Antagonism study with naloxone, suggests possible interaction of the new compounds with the opioid receptors.
- Al-Rashood,Madani,Ginawi,Ashraf,El-Obeid
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p. 1242 - 1245
(2007/10/02)
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- Spherical Cryptanes. Synthesis and Inclusion-Complexes of Spherical Macrotricyclic Ligands
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A general strategy for the synthesis of spherical macrotricyclic ligands has been developed.Four spherical cryptands, SC-24, SC-25, SC-26 and SC-27 have been obtained by this route.The synthesis and cation-complexing properties of these compounds are described in detail.Stability constants and cation exchange rates of the spherical cryptates obtained with alkali and alkali-earth cations have been determined.Highly stable complexes are formed by SC-24; the Rb+ and Cs+ cryptates of SC-24 are the most stable complexes of these cations known to date.The size of the intermolecular cavity affects the complexation selectivity.The cation exchange rates are very slow, and the corresponding free energies of activation are even larger than for macrobicyclic criptates of similar stability.Both the high complex stabilities and the high activation energies required for cation exchange indicate a marked 'spherical cryptate effect' resulting from the highly connected nature of the molecular architecture of spherical macrotricyclic ligands.
- Graf, Ernest,Lehn, Jean-Marie
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p. 1040 - 1057
(2007/10/02)
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- Synthesis of some 4-hydroxypiperazine and N.N.-dibenzylhydroxylamine esters with potential local anaesthetic activity.
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In the synthetic approach to some new local anaesthetics, it was desirable to prepare esters of N1-methyl-N4-hydroxypiperazine and N.N-dibenzylhydroxylamine. Their local anaesthetic activity testing is in progress.
- Rida,Issa,Beltagy
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p. 711 - 713
(2007/10/05)
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- Asymmetric macrocycles containing oxygen and binaphthyl ring members
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Chiral, hinged and functionalized host multiheteromacrocycles of the oxygen, nitrogen and sulfur-containing type are disclosed possessing holes sized to afford selective complexation of specific guest substances and shapes to recognize chirally guest molecules by virtue of the chiral steric barrier of the 2,2'-diheteroatom-1,1'-binaphthyl grouping, the naphthyl-naphthyl dihedral angle, and the provision of ortho positioned side chain substituents (arms) bearing terminal functional groups which act as counterions or additional complexing sites, and the provision of remote position side chain substituents used to control solubility and volatility properties or to bond the multiheteromacrocycles to solid supports.
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