K R Scott

Howard University, Вашингтон, West Virginia, United States

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Publications (55)148.82 Total impact

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    ABSTRACT: The title compounds, C9H7NO3, (1), C10H7NO5, (2), and C14H9NO5, (3), are three potentially anti-convulsant compounds. Compounds (1) and (2) are isoindoline derivatives and (3) is an iso-quinoline derivative. Compounds (2) and (3) crystallize with two independent mol-ecules (A and B) in their asymmetric units. In all three cases, the isoindoline and benzoiso-quinoline moieties are planar [r.m.s. deviations are 0.021 Å for (1), 0.04 and 0.018 Å for (2), and 0.033 and 0.041 Å for (3)]. The substituents attached to the N atom are almost perpendicular to the mean planes of the heterocycles, with dihedral angles of 89.7 (3)° for the N-O-Cmeth-yl group in (1), 71.01 (4) and 80.00 (4)° for the N-O-C(=O)O-Cmeth-yl groups in (2), and 75.62 (14) and 74.13 (4)° for the same groups in (3). In the crystal of (1), there are unusual inter-molecular C=O⋯C contacts of 2.794 (1) and 2.873 (1) Å present in mol-ecules A and B, respectively. There are also C-H⋯O hydrogen bonds and π-π inter-actions [inter-centroid distance = 3.407 (3) Å] present, forming slabs lying parallel to (001). In the crystal of (2), the A and B mol-ecules are linked by C-H⋯O hydrogen bonds, forming slabs parallel to (10-1), which are in turn linked via a number of π-π inter-actions [the most significant centroid-centroid distances are 3.4202 (7) and 3.5445 (7) Å], forming a three-dimensional structure. In the crystal of (3), the A and B mol-ecules are linked via C-H⋯O hydrogen bonds, forming a three-dimensional structure, which is consolidated by π-π inter-actions [the most significant inter-centroid distances are 3.575 (3) and 3.578 (3) Å].
    Acta Crystallographica Section E Structure Reports Online 12/2014; 70(Pt 12):456-61. DOI:10.1107/S1600536814023769 · 0.35 Impact Factor
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    ABSTRACT: In this paper, we investigated the previously synthesized anticonvulsant enaminone ethyl ester analogs using the computational gaussian 03 programs. The significant chemical features of the enaminone compounds that lead to positive anticonvulsant activity were identified. From our analyses, we believe that the neutrality of the phenyl ring may be important for binding in the hydrophobic pocket of the active site and that the binding of the phenyl substituent is the main reason why some analogs are active and others are inactive.
    Bioorganic & medicinal chemistry 03/2013; DOI:10.1016/j.bmc.2013.03.036 · 2.95 Impact Factor
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    ABSTRACT: The x-ray crystal structure of 3-((5-methylisoxazol-3-yl)amino)-5-methylcyclohex-2-enone (12b) and 3-((5-methylisoxazolyl-3-yl)amino)-5,5-dimethylcyclohex-2-enone (12c) were determined and correlated to their anticonvulsant activity in mice and rats. A hypothesis for the toxicity of the analogs are advanced. In addition, a series of 5-methyl-N-(3-oxocyclohex-1-enyl)-isoxazole-3-carboxamides were synthesized and evaluated for anticonvulsant activity. These compounds were compared to the activity of the corresponding amino and aminomethyl enaminones. Additional investigation involved the synthesis and evaluation of a trifluoromethyl analog of the active isoxazole tert-butyl 4-(5-methisoxazol-3-yl-amino)-6-methyl-2-oxo-cyclohex-3-ene carboxylate (4f).
    European Journal of Medicinal Chemistry 02/2012; 51:42-51. DOI:10.1016/j.ejmech.2012.02.003 · 3.43 Impact Factor
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    ABSTRACT: For the title compound, C(13)H(14)ClNO(3)S, geometrical parameters, determined using X-ray diffraction techniques, are compared with those calculated by density functional theory (DFT), using hybrid exchange-correlation functional, B3LYP methods. The dihedral angle between the benzene ring and the conjugated part of the cyclo-hexene ring is 87.47 (5)°. The cyclo-hexene ring and its substituents are disordered over two conformations, with occupancies of 0.786 (3) and 0.214 (3). In the crystal, mol-ecules are linked into chains in the c-axis direction by inter-molecular N-H⋯O(C=O) hydrogen bonds. C-H⋯O inter-actions are also observed.
    Acta Crystallographica Section E Structure Reports Online 09/2011; 67(Pt 9):o2272-3. DOI:10.1107/S1600536811030662 · 0.35 Impact Factor
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    ABSTRACT: In the title compound, C(14)H(16)ClNO, the dihedral angle between the benzene ring and the conjugated part of the cyclo-hexene ring is 61.7 (2)°. Part of the cyclo-hexene ring and one of the attached methyl groups are disordered over two orientations with occupancies of 0.602 (7) and 0.398 (7). In addition, the crystal studied was a racemic twin [Flack parameter = 0.58 (4)]. In the crystal, the mol-ecules are linked into chains in the b-axis direction by inter-molecular N-H⋯O hydrogen bonds. C-H⋯O and C-H⋯Cl inter-actions are also observed.
    Acta Crystallographica Section E Structure Reports Online 05/2011; 67(Pt 5):o1283-4. DOI:10.1107/S1600536811005678 · 0.35 Impact Factor
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    ABSTRACT: A small library of anilino enaminones was analyzed for potential anticonvulsant agents. We examined the effects of three anilino enaminones on neuronal activity of output neurons, mitral cells (MC), in an olfactory bulb brain slice preparation using whole-cell patch-clamp recording. These compounds are known to be effective in attenuating pentylenetetrazol-induced convulsions. Among the three compounds tested, 5-methyl-3-(4-trifluoromethoxy-phenylamino)-cyclohex-2-enone (KRS-5Me-4-OCF₃) showed potent inhibition of MC activity with an EC₅₀ of 24.5 μM. It hyperpolarized the membrane potential of MCs accompanied by suppression of spontaneous firing. Neither ionotropic glutamate receptor blockers nor a GABA(B) receptor blocker prevented the KRS-5Me-4-OCF(3)-evoked inhibitory effects. In the presence of GABA(A) receptor antagonists, KRS-5Me-4-OCF(3) completely failed to evoke inhibition of MC spiking activity, suggesting that KRS-5Me-4-OCF₃-induced inhibition may be mediated by direct action on GABA(A) receptors or indirect action through the elevation of tissue GABA levels. Neither vigabatrin (a selective GABA-T inhibitor) nor 1,2,5,6-tetrahydro-1-[2-[[(diphenylmethylene)amino]oxy]ethyl]-3-pyridinecarboxylic acid hydrochloride (NNC-711) (a selective inhibitor of GABA uptake by GABA transporter 1) eliminated the effect of KRS-5ME-4-OCF₃ on neuronal excitability, indicating that the inhibitory effect of the enaminone resulted from direct activation of GABA(A) receptors. The concentration-response curves for GABA are left-shifted by KRS-5Me-4-OCF₃, demonstrating that KRS-5Me-4-OCF₃ enhanced GABA affinity and acted as a positive allosteric modulator of GABA(A) receptors. The effect of KRS-5Me-4-OCF₃ was blocked by applying a benzodiazepine site antagonist, suggesting that KRS-5Me-4-OCF₃ binds at the classic benzodiazepine site to exert its pharmacological action. The results suggest clinical use of enaminones as anticonvulsants in seizures and as a potential anxiolytic in mental disorders.
    Journal of Pharmacology and Experimental Therapeutics 03/2011; 336(3):916-24. DOI:10.1124/jpet.110.173740 · 3.86 Impact Factor
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    ABSTRACT: In the title compound, C15H16F3NO2, the dihedral angle between the benzene ring and the conjugated part of the cyclohexene ring is 60.00 (8)degrees. The non-conjugated part of the cyclohexene ring and the trifluoromethyl group are both disordered over two sets of sites with occupancies of 0.835 (2) and 0.165 (2). In the crystal, molecules are linked into chains along [010] by intermolecular N-H center dot center dot center dot O hydrogen bonds. Weak intermolecular C-H center dot center dot center dot O interactions also occur.
    Acta Crystallographica Section E Structure Reports Online 03/2011; 67(Pt 3):o603-4. DOI:10.1107/S1600536811004338 · 0.35 Impact Factor
  • S. K. HONG, K. R. SCOTT, G. O. RANKIN
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    ChemInform 12/2010; 26(51). DOI:10.1002/chin.199551119
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    ABSTRACT: In the title compound, C(19)H(22)F(3)NO(4), the dihedral angle between the benzene ring and the conjugated part of the enaminone ring is 42.5 (1)degrees. The ester substituent makes a dihedral angle of 81.3 (2)degrees with this latter moiety. The crystal structure is held together by strong N-H center dot center dot center dot O and weak C-H center dot center dot center dot O intermolecular interactions. The enaminone ring is disordered over two orientations with relative occupancies of 0.794 (4) and 0.206 (4).
    Acta Crystallographica Section E Structure Reports Online 12/2010; 66(Pt 12):o3229. DOI:10.1107/S1600536810046969 · 0.35 Impact Factor
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    ChemInform 05/2010; 25(19). DOI:10.1002/chin.199419099
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    ABSTRACT: The objective of this work was to design enaminone esters that would possess potential medicinal properties. The reaction between beta-hydroxyketo esters and primary or secondary amines yielded secondary or tertiary enaminone esters, respectively. The UV spectra of the enaminone esters were determined in acidic, alkaline, and neutral media; the spectra have a hypsochromic shift in acidic media in comparison with neutral media. The enaminone esters provided nucleophilic and electrophilic sites for a variety of reactions. Thus, the enaminone esters were converted into enaminone amides and O-alkylation products exclusively. Although the enaminone esters were generally resistant to reduction by metal hydrides, one unhindered enaminone ester was reduced to an alcohol with sodium borohydride. Another enaminone ester reacted with guanidine to give the corresponding quinazolinone. Due to the variety of nucleophilic and electrophilic sites in the enaminone system, enaminone esters possess a great potential as reaction intermediates and medicinal compounds. Preliminary evaluations of the enaminone esters revealed a histaminergic effect, uterine relaxant properties, and anticonvulsant activity.
    Journal of Pharmaceutical Sciences 05/2010; 83(1):79-84. DOI:10.1002/jps.2600830119 · 3.01 Impact Factor
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    ChemInform 02/2010; 28(8). DOI:10.1002/chin.199708232
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    ABSTRACT: In a continuing evaluation of the aniline-substituted enaminones, the synthesis of additional para-substituted analogs has been made in an attempt to further quantify the electronic (sigma) and lipophilic (pi) requirements for anticonvulsant activity in this series. In addition, meta- and ortho-substituted and polysubstituted compounds have been synthesized and evaluated for anticonvulsant activity. In the para-substituted series, 4-cyano analogs (32 and 33) (+ sigma, - pi), which were highly active via intraperitoneal (ip) injection in mice, were inactive on oral (po) administration in rats. The para-substituted trifluoromethoxy (+ sigma, + pi) analog (8) had significant potency by both routes. Meta substitution limited the activity due to steric factors. Bromo and iodo substituents produced active para-substituted analogs (5 and 17) but were inactive when substituted in the meta position (37 and 41, respectively). Ortho substitution provided no clear relationship due to nonparametric deviations. Neither 1, the prototype enaminone, nor 2, the putative metabolite, produced significant nephrotoxicity or hepatotoxicity. Sodium channel binding of 1 and 8 indicated that 8 displayed relatively potent sodium channel binding but 1 showed weaker effects with IC50 values of 489 and 170 microM respectively against [3H]batrachotoxinin A 20 alpha-benzoate ([3H]BTX-B).
    Journal of Medicinal Chemistry 01/2010; 38(20):4033-43. DOI:10.1002/chin.199604118 · 5.48 Impact Factor
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    ABSTRACT: In the title compound, C(18)H(22)ClNO(3), the dihedral angle between the benzene ring and the conjugated part of the enaminone ring is 55.19 (9)°. The ester substituent makes a dihedral angle of 81.0 (2)° with this latter moiety. The crystal structure features N-H⋯O and weak C-H⋯O inter-molecular inter-actions.
    Acta Crystallographica Section E Structure Reports Online 01/2010; 67(Pt 1):o224. DOI:10.1107/S1600536810051743 · 0.35 Impact Factor
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    ABSTRACT: This article expands upon our original submission to the Eddington, N. D.; Cox, D. S.; Khurana, M.; Salama, N. N.; Stables, J. P.; Harrison, S. J.; Negussie, A.; Taylor, R. S.; Tran, U. Q.; Moore, J. A.; Barrow, J. C.; Scott, K. R. Eur. J. Med. Chem.2003, 38, 49 on a series of twenty (20) compounds, all 5-methyl-3-[(substituted)-phenylamino]-cyclohex-2-enone derivatives. This article provides the reasons why the compounds are active/inactive. By use of computational methods, the reasons for activity/inactivity are explained.
    Bioorganic & medicinal chemistry 05/2009; 17(14):5342-6. DOI:10.1016/j.bmc.2009.03.068 · 2.95 Impact Factor
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    ABSTRACT: 3D-QSAR studies comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were carried out on 26 structurally diverse subcutaneous pentylenetetrazol (scPTZ) active enaminone analogues, previously synthesized in our laboratory. CoMFA and CoMSIA were employed to generate models to define the specific structural and electrostatic features essential for enhanced binding to the putative GABA receptor. The 3D-QSAR models demonstrated a reliable ability to predict the CLogP of the active anticonvulsant enaminones, resulting in a q(2) of 0.558 for CoMFA, and a q(2) of 0.698 for CoMSIA. The outcomes of the contour maps for both models provide detailed insight for the structural design of novel enaminone derivatives as potential anticonvulsant agents.
    Bioorganic & medicinal chemistry 12/2008; 17(1):133-40. DOI:10.1016/j.bmc.2008.11.014 · 2.95 Impact Factor
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    ABSTRACT: Enaminones, enamines of beta-dicarbonyl compounds, have been known for many years. Their early use has been relegated to serving as synthetic intermediates in organic synthesis and of late, in pharmaceutical development. Recently, the therapeutic potential of these entities has been realized. This review provides the background and current research in this area with emphasis of these agents as potential anticonvulsants, their proposed mechanisms of action, and as potential modulators of multidrug resistance (MDR).
    Journal of Pharmaceutical Sciences 10/2007; 96(10):2509-31. DOI:10.1002/jps.20967 · 3.01 Impact Factor
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    ABSTRACT: Structure-activity relationship studies were employed to synthesize a series of 3- and 3,4-substituted benzamides from 3-amino-2-cyclohexenones. An improved method for the synthesis of benzamides from 3-amino-2-cyclohexenones is presented which provided significantly higher yields (71-79%) for the reported compounds. NMR and X-ray structural analyses were undertaken to note the possible intra- and intermolecular interactions of the synthesized analogs. Molecular modeling studies were used to determine the minimized configuration and were compared to their X-ray structures for correlation. These new entities were evaluated as potential anticonvulsants and type IV phosphodiesterase inhibitors (PDE4).
    Bioorganic & Medicinal Chemistry 03/2006; 14(4):997-1006. DOI:10.1016/j.bmc.2005.09.023 · 2.95 Impact Factor
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    ABSTRACT: The X-ray crystal structure of the title compound, C12H16N2O2, has been determined and its structure correlated with its anticonvulsant activity in mice and rats. In each of the two molecules of the asymmetric unit, the two rings are linked by an intramolecular C-H center dot center dot center dot N hydrogen bond.
    Acta Crystallographica Section E Structure Reports Online 01/2006; 62(1). DOI:10.1107/S1600536805040778/hg6282IIsup2.hkl · 0.35 Impact Factor

Publication Stats

832 Citations
148.82 Total Impact Points

Institutions

  • 1985–2014
    • Howard University
      • • Department of Pharmaceutical Science
      • • Department of Chemistry
      Вашингтон, West Virginia, United States
  • 2000–2004
    • University of Maryland, Baltimore
      • Department of Pharmaceutical Sciences (PSC)
      Baltimore, MD, United States