76
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Song Y, Clizbe L, Bhakta C, Teng W, Wong P, Huang B, Tran K, Sinha U, Park G, Reed A, Scarborough RM, Zhu BY. Design and synthesis of factor Xa inhibitors and their prodrugs. Bioorg Med Chem Lett 2003; 13:297-300. [PMID: 12482444 DOI: 10.1016/s0960-894x(02)00921-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In addition to our previously reported fluoro acrylamides Xa inhibitors 2 and 3, a series of potent and novel cyclic diimide amidine compounds has been identified. In efforts to improve their oral bioavailability, replacement of the amidine group with methyl amidrazone gives compounds of moderate potency (14, IC(50)=0.028 microM). In the amidoxime prodrug approach, the amidoxime compounds show good oral bioavailability in rats and dogs. High plasma level of prodrug 26 and significant concentration of active drug 26a were obtained upon oral administration of prodrug 26 in rats.
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77
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Black SL, Jales AR, Brandt W, Lewis JW, Husbands SM. The role of the side chain in determining relative delta- and kappa-affinity in C5'-substituted analogues of naltrindole. J Med Chem 2003; 46:314-7. [PMID: 12519069 DOI: 10.1021/jm020997b] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The role of the side chain in 5'-substituted analogues of naltrindole has been further explored with the synthesis of series of amides, amidines, and ureas. Amidines (8, 13) had greatest selectivity for the kappa receptor, as predicted from consideration of the message-address concept. It was also found that an appropriately located carbonyl group, in ureas (10) and amides (7), led to retention of affinity and antagonist potency at the delta receptor.
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78
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Hiratake J, Sakata K. Glycosylamidines as Potent Selective and Easily Accessible Glycosidase Inhibitors and Their Application to Affinity Chromatography. Methods Enzymol 2003; 363:421-44. [PMID: 14579594 DOI: 10.1016/s0076-6879(03)01070-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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79
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Matter H, Defossa E, Heinelt U, Blohm PM, Schneider D, Müller A, Herok S, Schreuder H, Liesum A, Brachvogel V, Lönze P, Walser A, Al-Obeidi F, Wildgoose P. Design and quantitative structure-activity relationship of 3-amidinobenzyl-1H-indole-2-carboxamides as potent, nonchiral, and selective inhibitors of blood coagulation factor Xa. J Med Chem 2002; 45:2749-69. [PMID: 12061878 DOI: 10.1021/jm0111346] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of 138 nonchiral 3-amidinobenzyl-1H-indole-2-carboxamides and analogues as inhibitors of the blood coagulation enzyme factor Xa (fXa) were designed, synthesized, and investigated by X-ray structure analysis and 3D quantitative structure-activity relationship (QSAR) studies (CoMFA, CoMSIA) in order to identify important protein-ligand interactions responsible for biological affinity and selectivity. Several compounds from this series are highly potent and selective inhibitors of this important enzyme linking extrinsic and intrinsic coagulation pathways. To rationalize biological affinity and to provide guidelines for further design, all compounds were docked into the factor Xa binding site. Those docking studies were based on X-ray structures of factor Xa in complex with literature-known inhibitors. It was possible to validate those binding modes by four X-ray crystal structures of representative ligands in factor Xa, while one ligand was additionally crystallized in trypsin to rationalize requirements for selective factor Xa inhibition. The 3D-QSAR models based on a superposition rule derived from these docking studies were validated using conventional and cross-validated r(2) values using the leave-one-out method and repeated analyses using two randomly chosen cross-validation groups plus randomization of biological activities. This led to consistent and highly predictive 3D-QSAR models with good correlation coefficients for both CoMFA and CoMSIA, which were found to correspond to experimentally determined factor Xa binding site topology in terms of steric, electrostatic, and hydrophobic complementarity. Subsets selected as smaller training sets using 2D fingerprints and maximum dissimilarity methods resulted in 3D-QSAR models with remarkable correlation coefficients and a high predictive power. The final quantitative SAR information agrees with all experimental data for the binding topology and thus provides reasonable activity predictions for novel factor Xa inhibitors.
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80
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Phillips G, Guilford WJ, Buckman BO, Davey DD, Eagen KA, Koovakkat S, Liang A, McCarrick M, Mohan R, Ng HP, Pinkerton M, Subramanyam B, Ho E, Trinh L, Whitlow M, Wu S, Xu W, Morrissey MM. Design, synthesis, and activity of a novel series of factor Xa inhibitors: optimization of arylamidine groups. J Med Chem 2002; 45:2484-93. [PMID: 12036356 DOI: 10.1021/jm0200660] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A novel series of diaryloxypyridines have been designed as selective nanomolar factor Xa (fXa) inhibitors for use as anticoagulants. In this paper, we describe our efforts to identify an additional interaction and a replacement for the distal amidine group that binds in the S3/S4 pocket of fXa. Introduction of a hydroxyl group para to the proximal amidine group increases the potency vs fXa by 1-2 orders of magnitude, which is the result of a hydrogen bond to Ser195 of the catalytic triad. A methyl imidazoline and a dimethylamide are good alternatives for the second amidine. These substitutions have increased the selectivity vs the related serine proteases trypsin and thrombin. The synthesis, in vitro activity, and hypothetical modes of binding to fXa based on trypsin crystallographic data are outlined.
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81
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Kraft A, Peters L, Fröhlich R. N,N',N",N"'-Tetraethylterephthalamidinium bis(tetrazolate). Acta Crystallogr C 2002; 58:o272-4. [PMID: 11983988 DOI: 10.1107/s0108270102004730] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2002] [Accepted: 03/12/2002] [Indexed: 11/10/2022] Open
Abstract
The crystal structure of the title 2:1 salt of tetrazole and a substituted terephthalamidine, C(16)H(28)N(4)(2+).2CHN(4)(-), contains an infinite network of hydrogen bonds, with short N.N distances of 2.820 (2) and 2.8585 (19) A between the tetrazolate anion and the amidinium cation. Involvement of the lateral N atoms of the tetrazole in the hydrogen bonding appears to be a typical binding pattern for the tetrazolate anion.
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82
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Rudolph MJ, Illig CR, Subasinghe NL, Wilson KJ, Hoffman JB, Randle T, Green D, Molloy CJ, Soll RM, Lewandowski F, Zhang M, Bone R, Spurlino JC, Deckman IC, Manthey C, Sharp C, Maguire D, Grasberger BL, DesJarlais RL, Zhou Z. Design and synthesis of 4,5-disubstituted-thiophene-2-amidines as potent urokinase inhibitors. Bioorg Med Chem Lett 2002; 12:491-5. [PMID: 11814826 DOI: 10.1016/s0960-894x(01)00787-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A study of the S1 binding of lead 5-methylthiothiophene amidine 3, an inhibitor of urokinase-type plasminogen activator, was undertaken by the introduction of a variety of substituents at the thiophene 5-position. The 5-alkyl substituted and unsubstituted thiophenes were prepared using organolithium chemistry. Heteroatom substituents were introduced at the 5-position using a novel displacement reaction of 5-methylsulfonylthiophenes and the corresponding oxygen or sulfur anions. Small alkyl group substitution at the 5-position provided inhibitors equipotent with but possessing improved solubility.
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83
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Sevillano LG, Melero CP, Caballero E, Tomé F, Lelièvre LG, Geering K, Crambert G, Carrón R, Medarde M, San Feliciano A. Inotropic activity of hydroindene amidinohydrazones. J Med Chem 2002; 45:127-36. [PMID: 11754584 DOI: 10.1021/jm0109309] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Several hydroindenic derivatives (7a-methyl-2,3,5,6,7,7a-hexahydro-1H-indenes), bearing an amidinohydrazone at C-5 and different moieties at C-1, have been synthesized and evaluated for their inotropic and chronotropic effects on right- and left-guinea-pig-atria activity. Three of them showed the same profile as digoxin, although with lower potency. The effect on Na(+),K(+)-ATPase (NKA) was also evaluated for these three compounds, observing that two of them, with the same absolute configuration as natural cardenolides, are also NKA inhibitors, while the compound with the opposite configuration lacks such an effect. More interestingly, both active compounds act without affecting the cardiac rhythm. This could be related to the selective inhibition of the human alpha2beta1 isozyme (associated with the inotropic effect) with respect to the alpha1beta1 isozyme (associated with the maintenance of basal ionic levels in the cell and the toxic effect of cardenolides).
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84
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Mackman RL, Katz BA, Breitenbucher JG, Hui HC, Verner E, Luong C, Liu L, Sprengeler PA. Exploiting subsite S1 of trypsin-like serine proteases for selectivity: potent and selective inhibitors of urokinase-type plasminogen activator. J Med Chem 2001; 44:3856-71. [PMID: 11689072 DOI: 10.1021/jm010244+] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A nonselective inhibitor of trypsin-like serine proteases, 2-(2-hydroxybiphenyl-3-yl)-1H-indole-5-carboxamidine (1) (Verner, E.; Katz, B. A.; Spencer, J.; Allen, D.; Hataye, J.; Hruzewicz, W.; Hui, H. C.; Kolesnikov, A.; Li, Y.; Luong, C.; Martelli, A.; Radika. K.; Rai, R.; She, M.; Shrader, W.; Sprengeler, P. A.; Trapp, S.; Wang, J.; Young, W. B.; Mackman, R. L. J. Med. Chem. 2001, 44, 2753-2771) has been optimized through minor structural changes on the S1 binding group to afford remarkably selective and potent inhibitors of urokinase-type plasminogen activator (uPA). The trypsin-like serine proteases(1) that comprise drug targets can be broadly categorized into two subfamilies, those with Ser190 and those with Ala190. A single-atom modification, for example, replacement of hydrogen for chlorine at the 6-position of the 5-amidinoindole P1 group on 1, generated up to 6700-fold selectivity toward the Ser190 enzymes and against the Ala190 enzymes. The larger chlorine atom displaces a water molecule (H(2)O1(S1)) that binds near residue 190 in all the complexes of 1, and related inhibitors, in uPA, thrombin, and trypsin. The water molecule, H(2)O1(S1), in both the Ser190 or Ala190 enzymes, hydrogen bonds with the amidine N1 nitrogen of the inhibitor. When it is displaced, a reduction in affinity toward the Ala190 enzymes is observed due to the amidine N1 nitrogen of the bound inhibitor being deprived of a key hydrogen-bonding partner. In the Ser190 enzymes the affinity is maintained since the serine hydroxyl oxygen O gamma(Ser190) compensates for the displaced water molecule. High-resolution crystallography provided evidence for the displacement of the water molecule and validated the design rationale. In summation, a novel and powerful method for engineering selectivity toward Ser190 proteases and against Ala190 proteases without substantially increasing molecular weight is described.
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85
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Basiuk VA. Condensation of vaporous amino acids in the presence of silica. Formation of bi- and tricyclic amidines. ORIGINS LIFE EVOL B 2001; 22:333-48. [PMID: 11536511 DOI: 10.1007/bf01809370] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Amino acids (alanine, valine, norvaline, leucine, and 2-aminoisobutyric acid) were subjected to repeated (5-9 times) sublimation in the presence of silica at temperature of 220-240 degrees C. The major amino acid condensation products were diketopiperazines (DKPs) in yields of 27-89%. Mixtures of by-products have been isolated from the DKPs by means of chloroform extraction. On the basis of fast atom bombardment mass spectrometric studies of the mixtures it is proposed that under these conditions further dehydration proceeds resulting in bicyclic (BCA) and tricyclic (TCA) amidine derivatives of DKPs; the BCA formation has been confirmed by means of IR and 1H NMR spectroscopy in the case of 2-aminoisobutyric acid. During the sublimation, thermal destruction of the cyclic products was also observed accompanied by the cycle degradation and cleavage of alkyl substituents. The BCAs and TCAs are considered as possible sources of linear di- and tripeptides.
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86
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Su T, Wu Y, Doughan B, Kane-Maguire K, Marlowe CK, Kanter JP, Woolfrey J, Huang B, Wong P, Sinha U, Park G, Malinowski J, Hollenbach S, Scarborough RM, Zhu BY. Design and synthesis of glycolic and mandelic acid derivatives as factor Xa inhibitors. Bioorg Med Chem Lett 2001; 11:2279-82. [PMID: 11527714 DOI: 10.1016/s0960-894x(01)00447-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A series of glycolic and mandelic acid derivatives was synthesized and investigated for their factor Xa inhibitory activity. These analogues are highly potent and selective inhibitors against fXa. In a rabbit deep vein thrombosis model, compound 26 showed significant antithrombotic effects (81% inhibition of thrombus formation) at 1.1 microM plasma concentration following intravenous administration.
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87
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Verner E, Katz BA, Spencer JR, Allen D, Hataye J, Hruzewicz W, Hui HC, Kolesnikov A, Li Y, Luong C, Martelli A, Radika K, Rai R, She M, Shrader W, Sprengeler PA, Trapp S, Wang J, Young WB, Mackman RL. Development of serine protease inhibitors displaying a multicentered short (<2.3 A) hydrogen bond binding mode: inhibitors of urokinase-type plasminogen activator and factor Xa. J Med Chem 2001; 44:2753-71. [PMID: 11495587 DOI: 10.1021/jm0100638] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Novel scaffolds that bind to serine proteases through a unique network of short hydrogen bonds to the catalytic Ser195 have been developed. The resulting potent serine protease inhibitors were designed from lead molecule 2-(2-hydroxyphenyl)1H-benzoimidazole-5-carboxamidine, 6b, which is known to display several modes of binding. For instance, 6b can recruit zinc and bind in a manner similar to that reported by bis(5-amidino-2-benzimidazolyl)methane (BABIM) (Nature 1998, 391, 608-612).(1) Alternatively, 6b can bind in the absence of zinc through a multicentered network of short (<2.3 A) hydrogen bonds. The lead structure was optimized in the zinc-independent binding mode toward a panel of six human serine proteases to yield optimized inhibitors such as 2-(3-bromo-2-hydroxy-5-methylphenyl)-1H-indole-5-carboxamidine, 22a, and 2-(2-hydroxybiphenyl-3-yl)-1H-indole-5-carboxamidine, 22f. Structure-activity relationships determined that, apart from the amidine function, an indole or benzimidazole and an ortho substituted phenol group were also essential components for optimal potency. The affinities (K(i)) of 22a and 22f, for example, bearing these groups ranged from 8 to 600 nM toward a panel of six human serine proteases. High-resolution crystal structures revealed that the binding mode of these molecules in several of the enzymes was identical to that of 6b and involved short (<2.3 A) hydrogen bonds among the inhibitor hydroxyl oxygen, Ser195, and a water molecule trapped in the oxyanion hole. In summation, novel and potent trypsin-like serine protease inhibitors possessing a unique mode of binding have been discovered.
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88
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Klinghofer V, Stewart K, McGonigal T, Smith R, Sarthy A, Nienaber V, Butler C, Dorwin S, Richardson P, Weitzberg M, Wendt M, Rockway T, Zhao X, Hulkower KI, Giranda VL. Species specificity of amidine-based urokinase inhibitors. Biochemistry 2001; 40:9125-31. [PMID: 11478879 DOI: 10.1021/bi010186u] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Inhibition of the proteolytic activity of urokinase has been shown to inhibit the progression of tumors in rodent models and is being investigated for use in human disease. Understanding the rodent/human species-specificity of urokinase inhibitors is therefore critical for interpretation of rodent cancer progression models that use these inhibitors. We report here studies with a panel of 11 diverse urokinase inhibitors in both human and mouse enzymatic assays. Inhibitors such as amiloride, B428, and naphthamidine, that occupy only the S1 subsite pocket were found to be nearly equipotent between the human and the murine enzymes. Inhibitors that access additional, more distal, pockets were significantly more potent against the human enzyme but there was no corresponding potency increase against the murine enzyme. X-ray crystallographic structures of these compounds bound to the serine protease domain of human urokinase were solved and examined in order to explain the human/mouse potency differences. The differences in inhibitor potency could be attributed to four amino acid residues that differ between murine and human urokinases: 60, 99, 146, and 192. These residues are Asp, His, Ser, and Gln in human and Gln, Tyr, Glu, and Lys in mouse, respectively. Compounds bearing a cationic group that interacts with residue 60 will preferentially bind to the human enzyme because of favorable electrostatic interactions. The hydrogen bonding to residue 192 and steric considerations with residues 99 and 146 also contribute to the species specificity. The nonparallel human/mouse enzyme inhibition observations were extended to a cell-culture assay of urokinase-activated plasminogen-mediated fibronectin degradation with analogous results. These studies will aid the interpretation of in vivo evaluation of urokinase inhibitors.
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89
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Delarue S, Girault S, Dali Ali F, Maes L, Grellier P, Sergheraert C. "One-pot" synthesis and antimalarial activity of formamidine derivatives of 4-anilinoquinoline. Chem Pharm Bull (Tokyo) 2001; 49:933-7. [PMID: 11515580 DOI: 10.1248/cpb.49.933] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Amodiaquine (AQ) is an antimalarial which is effective against chloroquino-resistant strains of Plasmodium falciparum but whose clinical use is severely restricted because of associated hepatotoxicity and agranulocytosis. "One-pot" synthesis of formamidines likely to be transformed into AQ derivatives is reported. Compared with AQ, the new compounds were devoid of in vitro cytotoxicity upon human embryonic lung cells and mouse peritoneal macrophages. One showed a potent in vivo activity in mice infected with P berghei. Transformation of this compound by reductive amination led to a new type of AQ derivatives that displayed an in vitro activity similar to that of AQ but did not lead to toxic quinone-imines.
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90
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Yeh CY, Miller SE, Carpenter SD, Nocera DG. Structurally homologous beta- and meso-amidinium porphyrins. Inorg Chem 2001; 40:3643-6. [PMID: 11421722 DOI: 10.1021/ic001387+] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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91
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Bielawski K, Bielawska A, Wołczyński S. Aromatic extended bisamidines: synthesis, inhibition of topoisomerases, and anticancer cytotoxicity in vitro. Arch Pharm (Weinheim) 2001; 334:235-40. [PMID: 11512274 DOI: 10.1002/1521-4184(200107)334:7<235::aid-ardp235>3.0.co;2-#] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A series of four aromatic extended bisamidines (12-15) differing in the nature of their terminal basic side chains were synthesized and evaluated for cytotoxic activity in MCF-7 cultured breast cancer cells. The concentrations of 12, 13, 14, and 15 needed to inhibit [3H]thymidine incorporation into DNA by 50% (IC50) were found to be 63 microM, 85 microM, 77 microM, and 97 microM, respectively. To test whether cytotoxic properties were related to DNA-binding and topoisomerase action, the bisamidines 12-15 were evaluated in a cell-free system. Data from the ethidium displacement assay showed that bisamidines 12-15 have significant affinity for DNA and show moderate specificity for AT base pairs. In the topoisomerase II assay, the relaxation of DNA was inhibited with all four drugs and the extent of inhibition was directly proportional to the drug concentration. This suggests that DNA binding may be implicated in the cytotoxicity of these bisamidines, possibly by inhibiting interactions between topoisomerase II and their DNA targets.
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92
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Weidner-Wells MA, Ohemeng KA, Nguyen VN, Fraga-Spano S, Macielag MJ, Werblood HM, Foleno BD, Webb GC, Barrett JF, Hlasta DJ. Amidino benzimidazole inhibitors of bacterial two-component systems. Bioorg Med Chem Lett 2001; 11:1545-8. [PMID: 11412977 DOI: 10.1016/s0960-894x(01)00024-5] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Amidino benzimidazoles have been identified as inhibitors of the bacterial KinA/Spo0F two-component system (TCS). Many of these inhibitors exhibit good in vitro antibacterial activity against a variety of susceptible and resistant Gram-positive organisms. The moiety at the 2-position of the benzimidazole was extensively modified. In addition, the regioisomeric benzoxazoles, heterocyclic replacements for the benzimidazole, have been synthesized and their activity against the TCS evaluated.
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93
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Sulyok GA, Gibson C, Goodman SL, Hölzemann G, Wiesner M, Kessler H. Solid-phase synthesis of a nonpeptide RGD mimetic library: new selective alphavbeta3 integrin antagonists. J Med Chem 2001; 44:1938-50. [PMID: 11384239 DOI: 10.1021/jm0004953] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The solid-phase synthesis of a low molecular weight RGD mimetic library is described. Activities of the compounds in inhibiting the interaction of ligands, vitronectin and fibrinogen, with isolated immobilized integrins alphavbeta3 and alphaIIbbeta3 were determined in a screening assay. Highly active and selective nonpeptide alphavbeta3 integrin antagonists with regard to orally bioavailability were developed, based on the aza-glycine containing lead compound 1. An important variation is the substitution of the aspartic amide of 1 by an aromatic residue. Furthermore, different guanidine mimetics have been incorporated to improve the pharmacokinetic profile. Exchange of the beta-amino acid NH by a methylene moiety in one set of RGD mimetics leads to the azacarba analogue compounds representing a novel peptidomimetic approach, which should increase the metabolic stability.
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Abstract
Discoveries that lead to ZK 807834 (CI-1031, 2a), a potent and selective factor Xa (fXa) inhibitor currently in clinical testing as an intravenous antithrombotic, were initiated by the identification of the potent (Z,Z)-isomer of BABCH (1c). A structure-activity relationship (SAR) was established with a series of analogues of BABCH. This SAR database, combined with computer modeling, demonstrated that binding of the second basic group in the S3/S4 pocket provided fXa potency and that a carboxylic acid group on the opposite side of the molecule resulted in selectivity versus thrombin. Simple substitution of a cyclic urea for the unsaturated ketone structure of BABCH gave disappointing results, but discovery of the bisphenoxy-pyridine analogues provided a template that could be readily optimized. The SAR established for this template is described and compared with computer modeling, REDOR NMR and X-ray crystallography studies. Inhibitor binding to fXa was increased by the introduction of a hydroxyl group on the proximal phenylamidine ring and by the introduction of fluorine atoms at C-3 and C-5 of the pyridine ring. Pharmacokinetic parameters were improved by balancing the contributions from the substituents on the distal ring and the central pyridine ring. The optimal combination was a methyl-(2H)-imidazoline group on the distal ring and a sarcosine at C-4 of the pyridine ring. The promising preclinical database for CI-1031 is described. This review relates the SAR leading to the discovery of the clinical candidate, CI-1031 directly to our best understanding of how this potent inhibitor interacts with the fXa active site.
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95
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Overman LE, Wolfe JP. Synthesis of polycyclic guanidines by cyclocondensation reactions of N-amidinyliminium ions. J Org Chem 2001; 66:3167-75. [PMID: 11325284 DOI: 10.1021/jo0100998] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new method for the synthesis of polycyclic guanidines is described. The N-amidinyliminium ion generated from alpha-(phenylthio)amidine precursor 16 by reaction with Cu(OTf)(2) undergoes cyclocondensation with 1,3-dienes, styrenes, and beta-dicarbonyl compounds to give 1-iminohexahydropyrrolo[1,2-c]pyrimidines having side chains at C3 and C7. In all cases, major products have a cis relationship of the C7 side chain and angular C4a hydrogen, whereas C3 side chains are incorporated with lower stereoselectivity (dr = 2--5:1) in cyclocondensations with dienes and styrenes to give stereoisomer 39 as the major product. In contrast to most cycloadditions of alkenes with N-acyliminium ions, cyclocondensations of alkenes with N-amidinyliminium ions proceed by a stepwise pathway. Cyclocondensation of the cognate ureido aminal 31 with styrene provides the rare 2-imino-5,6-dihydro-4H-1,3-oxazine derivative 32, rather than a pyrimidine as the major product. The high stereoselectivity observed in condensations of 16 with benzyl acetoacetate to afford Biginelli adduct 29 supports the intermediacy of N-amidinyliminium ions in related tethered Biginelli condensations of guanidines reported earlier from our laboratories.
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96
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Stephens CE, Tanious F, Kim S, Wilson WD, Schell WA, Perfect JR, Franzblau SG, Boykin DW. Diguanidino and “Reversed” Diamidino 2,5-Diarylfurans as Antimicrobial Agents. J Med Chem 2001; 44:1741-8. [PMID: 11356109 DOI: 10.1021/jm000413a] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dicationic 2,5-bis(4-guanidinophenyl)furans 5a-5f, 2,5-bis[4-(arylimino)aminophenyl]furans 6a-6b and 6e-6k, and 2,5-bis[4-(alkylimino)aminophenyl]furans 6c-6d have been synthesized starting from 2,5-bis[tri-n-butylstannyl]furan. Thermal melting studies with poly dA*dT and the duplex oligomer d(CGCGAATTCGCG)2 demonstrated high DNA binding affinities for a number of the compounds. The binding affinities are highly dependent on structure and are significantly affected by substituents both on the phenyl rings of the 2,5-diphenylfuran nucleus and on the cationic centers. Of the 17 novel dicationic compounds synthesized, six (6a, 6b, 5b, 6f, 6h, 6i) exhibited MICs of 2 microg/mL or less versus Mycobacterium tuberculosis. Of the compounds screened against Candida albicans, three gave MICs of 2 microg/mL or less (5b, 6h, 6i), and two (5b, 6i) were fungicidal, unlike a standard antifungal drug fluconazole, which was fungistatic. In addition, one of the tested compounds (6i) exhibited a MIC of <1 microg/mL against Aspergillus fumigatus, while also being a fungicidal against this organism. Finally, when evaluated against an expanded fungal panel, compound 6h showed good activity against Cryptococcus neoformans and Rhizopus arrhizus.
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97
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Wilson KJ, Illig CR, Subasinghe N, Hoffman JB, Rudolph MJ, Soll R, Molloy CJ, Bone R, Green D, Randall T, Zhang M, Lewandowski FA, Zhou Z, Sharp C, Maguire D, Grasberger B, DesJarlais RL, Spurlino J. Synthesis of thiophene-2-carboxamidines containing 2-aminothiazoles and their biological evaluation as urokinase inhibitors. Bioorg Med Chem Lett 2001; 11:915-8. [PMID: 11294390 DOI: 10.1016/s0960-894x(01)00102-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The serine protease urokinase (uPa) has been implicated in the progression of both breast and prostate cancer. Utilizing structure based design, the synthesis of a series of substituted 4-[2-amino-1,3-thiazolyl]-thiophene-2-carboxamidines is described. Further optimization of this series by substitution of the terminal amine yielded urokinase inhibitors with excellent activities.
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98
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Clement B, Christiansen K, Girreser U. Phase 2 metabolites of N-hydroxylated amidines (amidoximes): synthesis, in vitro formation by pig hepatocytes, and mutagenicity testing. Chem Res Toxicol 2001; 14:319-26. [PMID: 11258982 DOI: 10.1021/tx000105f] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A pig hepatocyte culture system was used for phase 2 biotransformation studies in vitro. The viability of the cultured hepatocytes was characterized daily during cultivation by lactate dehydrogenase release into the supernatant and albumin synthesis of the cells. The metabolic activity of the hepatocyte cultures was measured by 7-ethoxycoumarin (ECOD) and 7-ethoxyresorufin O-deethylation (EROD). The viability and metabolic activity of these pig hepatocytes were preserved for several days by culturing the cells in a monolayer culture system. Besides the known reduction of N-hydroxylated benzamidine (benzamidoxime) (2) to benzamidine (1), glucuronidation and, to a much smaller extent, sulfation of 2 to benzamidoxime O-glucuronide (3) and benzamidoxime O-sulfate (4) by cultured pig hepatocytes were found. The analyses were performed using HPLC and LC/MS studies. For unequivocal assignment, the hitherto unknown metabolites 3 and 4 were synthesized and characterized by spectroscopic techniques. Examination of benzamidoxime O-glucuronide and benzamidoxime O-sulfate for mutagenicity by means of the Ames test revealed that both phase 2 conjugates have no mutagenic effects in the TA98 and TA100 strains. So the phase 2 conjugation of benzamidoxime is significant in terms of detoxification.
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99
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Magdolen V, Arroyo de Prada N, Sperl S, Muehlenweg B, Luther T, Wilhelm OG, Magdolen U, Graeff H, Reuning U, Schmitt M. Natural and synthetic inhibitors of the tumor-associated serine protease urokinase-type plasminogen activator. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2001; 477:331-41. [PMID: 10849761 DOI: 10.1007/0-306-46826-3_36] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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100
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Wang L, Carrasco C, Kumar A, Stephens CE, Bailly C, Boykin DW, Wilson WD. Evaluation of the influence of compound structure on stacked-dimer formation in the DNA minor groove. Biochemistry 2001; 40:2511-21. [PMID: 11327873 DOI: 10.1021/bi002301r] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The Human Genome Project as well as sequencing of the genomes of other organisms offers a wealth of DNA targets for both therapeutic and diagnostic applications, and it is important to develop additional DNA binding motifs to fully exploit the potential of this new information. We have recently found that an aromatic dication, DB293, with an amidine-phenyl-furan-benzimidazole-amidine structure can recognize specific sequences of DNA by binding in the minor groove as a dimer [Wang, L., Bailly, C., Kumar, A., Ding, D., Bajic, M., Boykin, D. W., and Wilson, W. D. (2000) Proc. Natl. Acad. Sci. U.S.A. 97, 12-16]. The dimer binding is strong, highly cooperative and, in contrast to many closely related heterocyclic dications, has both GC and AT base pairs in the minor groove binding site. The aromatic heterocycle stacked dimer is quite different in structure from the polyamide-lexitropsin type compounds, and it is a dication while all lexitropsin dimers are monocations. The heterocyclic dimer represents only the second small molecule class that can recognize mixed sequences of DNA. To test the structural limits on the new type of complex, it is important to probe the influence of compound charge, chemical groups, and structural features. The effects of these compound molecular variations on DNA complex formation with several DNA sequences were evaluated by DNase I footprinting, CD and UV spectroscopy, thermal melting, and quantitative analysis with surface plasmon resonance biosensor methods. Conversion of the amidines to guanidinium groups does permit the cooperative dimer to form but removal of one amidine or addition of an alkyl group to the amidine strongly inhibited dimer formation. Changing the phenyl of DB293 to a benzimidazole or the benzimidazole to a phenyl or benzofuran also inhibited dimer formation. The results show that formation of the minor groove stacked-dimer complex is very sensitive to compound structure. The discovery of the aromatic dimer mode offers new opportunities to enhance the specificity and expand the range of applications of the compounds that target DNA.
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