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Letters in Drug Design & Discovery, Volume 2, No. 3, 2005

 

Contents

 

Role of a2-Antiplasmin in Cardiovascular System Pp.172-176

En Shu, Hiroyuki Matsuno, Yasuo Kitajima and Osamu Kozawa

[Abstract]  

 

Peptide Mimetic Factor VIIa Inhibitor: Importance of Hydrophilic Pocket in S2 Site to Improve Selectivity Against Thrombin Pp.177-181

S. Kadono, A. Sakamoto, Y. Kikuchi, M. Oh-eda, N. Yabuta, T. Koga, K. Hattori, T. Shiraishi, M. Haramura, H. Kodama, T. Esaki, H. Sato, Y. Watanabe, S. Itoh, M. Ohta and T. Kozono

[Abstract]  

 

A Cellular ELISA to Screen Lectin-Like Compounds for Cancer Cell Binding Pp.182-188

C-P. Chang, W-C. Cheng and H-Y. Lei

[Abstract]  

 

A Facile Synthesis of C2-Substituted Pyrrolo[2,3-f]quinolines with Cytotoxic Activity Pp.189-192

Andrew Tsotinis, Margarita Vlachou, Spyridon Zouroudis, Andras Jeney, Ferenc Timar, David E. Thurston and Christos Roussakis

[Abstract]  

 

Impact of Oral Administration of the Surface-Active Excipient Solutol HS 15 on the Pharmacokinetics of Intravenously Administered Colchicine Pp.193-195

B. Bittner, R.C. Bravo Gonzalez, I. Walter and J. Huwyler

[Abstract]  

 

Evaluation of Thermal Cisplatin Sensitization in Chicken DT40 Cells, Normal and Deficient, in DNA Homologous and Nonhomologous Endjoining Repair Pp.196-200

G.P. Raaphorst and J- Maude Leblanc

[Abstract]  

 

Preliminary In vitro Results Indicating Tartronic Acids as Aspartic Acid Mimetics in Vitronectin Receptor Antagonists: Evidence for Increased Hydroxyapatite Affinity Pp.201-204

Diane B. Hauze, Kenneth L. Kees, Charles W. Mann, Horace Fletcher III, Richard Murrills, Jeanne Matteo, Frederick Bex, Bheem Bhat and Valerie Coleburn

[Abstract]  

 

An Approach Towards the Quantitative Structure-Activity Relationships for Sulfamate-Based Estrone Sulfatase Inhibitors Pp.205-218

Rajeshwar P. Verma

[Abstract]

 

Pyrazinobenzodiazepines as Potent Nonpeptide Vasopressin Receptor Antagonists Pp.219-223

Jay M. Matthews, Dennis J. Hlasta, Patricia Andrade-Gordon, Keith T. Demarest, Eric Ericson, Joseph W. Gunnet, William Hageman, Richard Look, John B. Moore, and Bruce E. Maryanoff

[Abstract]

 

Synthesis and Characterization of a Novel Protein Tyrosine Phosphatase Inhibitor, 2-(Cyclobutylamino)- N- (2-Furylmethyl)-2-Thioxoacetamide Pp.224-227

Y. Kobayashi-Matsunaga, T. Ishii, T. Hamaguchi, H. Osada and M. Sato

[Abstract]

 

Expression of a6b4 and a3b1 Integrins in Bullous Pemphigoid and Pemphigus Vulgaris Pp.228-231

G. Giannelli, C. Foti, C. Divella, F. Marinosci, D. Bonamonte and S. Antonaci

[Abstract]  

 

Molecular Modeling for Quantitative Analysis of Molecular Interaction Pp.232-238

Toshihiko Hanai

[Abstract]  

 

Ascorbic Acid as Modulator of Immune Function in Sepsis Pp.239-244

V.M. Victor

[Abstract]

 

Difficulties in the Management of Frontal Dementia: Therapeutics Strategies Pp.245-249

Rita Moretti, Paola Torre, Rodolfo M. Antonello, Tatiana Cattaruzza and Giuseppe Cazzato

[Abstract]  

 

Design of a New Phosphate Binder, Anion Exchange Resin, Based on Microcalorimeter Measurements Pp.250-254

Hiroyoshi Inoue and Sho-ichi Yamagishi

[Abstract]  

 

Abstracts

 

[Back to top] Role of a2-Antiplasmin in Cardiovascular System

En Shu, Hiroyuki Matsuno, Yasuo Kitajima and Osamu Kozawa

 

Inhibition of the blood fibrinolytic system (plasminogen/plasmin) occurs either at the level of plasminogen activators, regulated by specific plasminogen activator inhibitors (PAIs) or at the level of plasmin, mainly regulated by a2-antiplasmin (a2-AP). In this contribution, we focused on the roles of a2-AP in acute myocardial infarction and vascular remodeling associated with cardiovascular diseases. Our findings have identified a new target for the development of new therapeutics for the clinical therapy of cardiovascular diseases.

 

[Back to top] Peptide Mimetic Factor VIIa Inhibitor: Importance of Hydrophilic Pocket in S2 Site to Improve Selectivity Against Thrombin

S. Kadono, A. Sakamoto, Y. Kikuchi, M. Oh-eda, N. Yabuta, T. Koga, K. Hattori, T. Shiraishi, M. Haramura, H. Kodama, T. Esaki, H. Sato, Y. Watanabe, S. Itoh, M. Ohta and T. Kozono

 

X-ray structure analysis of human factor VIIa/soluble tissue factor in complex with a peptide mimetic inhibitor reveals that Asp60, Tyr94, and Thr98 in the S2 site play an important role for the improvement of selectivity against thrombin.

 

[Back to top] A Cellular ELISA to Screen Lectin-Like Compounds for Cancer Cell Binding

C-P. Chang, W-C. Cheng and H-Y. Lei

 

Lectins are carbohydrate-binding proteins that can modulate cellular activity through cell membrane glycoproteins. A cell-based binding was set up to screen the lectin-like substances in natural products. Lectins, after binding to tumor cells, are detected with a biotinylated carbohydrate-polyacrylamide complex by ELISA. Sugar specificity can also be determined within the assay.

 

[Back to top] A Facile Synthesis of C2-Substituted Pyrrolo[2,3-f]quinolines with Cytotoxic Activity

Andrew Tsotinis, Margarita Vlachou, Spyridon Zouroudis, Andras Jeney, Ferenc Timar, David E. Thurston and Christos Roussakis

 

An expeditious four-step synthesis of the 1H-pyrrolo[2,3-f]quinoline-2-carboxamides (5a-h) is described. Readily available 6-quinolinecarboxaldehyde is converted to the parent acid (6) by nucleophilic attack of the azido-ester (9) and intramolecular cyclization of (10) followed by hydrolysis of the methyl ester (11). The cytotoxicity of the target molecules (5a-h) was evaluated in four tumour cell lines in vitro. One compound (5d) showed sufficient activity (IC50 = 10.2 µM) in the human non-small cell lung cell line NSCLCN16- L16 to be worthy of further study.

 

[Back to top] Impact of Oral Administration of the Surface-Active Excipient Solutol HS 15 on the Pharmacokinetics of Intravenously Administered Colchicine

B. Bittner, R.C. Bravo Gonzalez, I. Walter and J. Huwyler

 

Formulation ingredients may influence the pharmacokinetics of co-administered drugs. We investigated whether oral pre-dosing with the ‘inactive’ formulation ingredient Solutol affects the pharmacokinetic profile of intravenously administered colchicine in rats. Colchicine was administered intravenously to male Wistar rats as solution in isotonic sodium chloride (NaCl 0.9%, control group) at 1.5 mg/kg. A second group of rats received the intravenous dose of colchicine 20 minutes after oral pre-dosage with 4 mg/kg of a 90:10 (v/v) mixture of NaCl 0.9% and Solutol HS 15 (Solutol). At predetermined time points, plasma and urine were collected from the animals and analyzed for colchicine and its demethylated metabolites by LC/MS-MS. After oral pre-treatment with Solutol, colchicine plasma clearance (Cl) was decreased by a factor of two and its maximum plasma concentration (cmax) was almost twofold increased as compared to the control group. Moreover, the amount of parent colchicine excreted into urine within 24 hours after administration did increase twentyfold in the Solutol treated group. Renal excretion of colchicine metabolites was slightly increased. We conclude that absorption of Solutol and/or its degradation products into the systemic circulation seems to be a major contributor to the observed effects. Our results suggest that oral administration of formulation ingredients may alter the distribution kinetics of drugs, which are co-administered orally as well as intravenously.

 

[Back to top] Evaluation of Thermal Cisplatin Sensitization in Chicken DT40 Cells, Normal and Deficient, in DNA Homologous and Nonhomologous Endjoining Repair

G.P. Raaphorst and J- Maude Leblanc

 

Hyperthermia has been shown in many studies to be a strong sensitizer for cisplatin treatment and this sensitization may be in part due to the inhibition of DNA repair processes. We have set out to test this in cells with specific gene knockouts for known repair processes. The chicken DT40 cell system was used with a parental line (DT40) and knockouts of homologous recombination (HR) repair DT40Rad54, nonhomologous recombination endjoining (NHEJ) repair (DT40Ku70) and a double knockout mutant DT40Ku70Rad54. The results show that thermal cisplatin sensitization was achieved in all cell lines when hyperthermia at 45oC for 1.5h was given before cisplatin treatment and 42oC hyperthermia was given concurrently with cisplatin treatment. The data show that inhibition of the HR repair system did not significantly affect sensitization, while inhibition of NHEJ reduced thermal sensitization at low cisplatin doses and short treatments and for concurrent treatments. These data indicate that there may be a partial involvement of NHEJ in thermal cisplatin sensitization under specific treatment conditions.

 

[Back to top] Preliminary In vitro Results Indicating Tartronic Acids as Aspartic Acid Mimetics in Vitronectin Receptor Antagonists: Evidence for Increased Hydroxyapatite Affinity

Diane B. Hauze, Kenneth L. Kees, Charles W. Mann, Horace Fletcher III, Richard Murrills, Jeanne Matteo, Frederick Bex, Bheem Bhat and Valerie Coleburn

 

A series of tartronic acid analogs of a non-peptide RGD mimetic were prepared and evaluated both for antagonism of the vitronectin receptor and for affinity to hydroxyapatite, the main inorganic component of bone matrix. The hydroxy bis acid unit was found to be optimal for both receptor binding and hydroxyapatite affinity, while the N-terminus affected only receptor binding affinity.

 

[Back to top] An Approach Towards the Quantitative Structure-Activity Relationships for Sulfamate-Based Estrone Sulfatase Inhibitors

Rajeshwar P. Verma

 

Estrone sulfatase (ES) is a membrane-bound enzyme that is responsible for maintaining high levels of estrogens in breast cancer cells. This may be due to the conversion of estrone-sulfate into estrone by estronesulfatase, which acts as a pool of potentially available estrogens. There is now abundant evidence that estrogens have a pivotal role in the growth and development of hormone-dependent breast cancer. Thus, inhibitors of ES should have considerable therapeutic potential for the treatment of hormone-dependent breast cancer. Recently, a large number of sulfamate-based steroidal and non-steroidal ES inhibitors have been developed. The sulfamate moiety is believed to be involved in the irreversible inhibition of ES. In the present paper, we have undertaken quantitative structure-activity relationships for different series of non-steroidal sulfamate-based compounds in order to understand the chemical-biological interactions governing their inhibitory potency against ES. QSAR results have shown that the inhibitory potency against ES for these nonsteroidal sulfamate-based compounds is largely dependent on their hydrophobicity and molar refractivity.

 

[Back to top] Pyrazinobenzodiazepines as Potent Nonpeptide Vasopressin Receptor Antagonists

Jay M. Matthews, Dennis J. Hlasta, Patricia Andrade-Gordon, Keith T. Demarest, Eric Ericson, Joseph W. Gunnet, William Hageman, Richard Look, John B. Moore and Bruce E. Maryanoff

 

We have identified a novel series of tricyclic pyrazinobenzodiazepines, represented by general structure 2, as potent vasopressin receptor antagonists. For example, 3 binds with high affinity to human V2 receptors and is very selective relative to V1a receptors. Compound (R)-(+)-3 exhibited pronounced aquaretic activity in rats and dogs on oral administration.

 

[Back to top] Synthesis and Characterization of a Novel Protein Tyrosine Phosphatase Inhibitor, 2-(Cyclobutylamino)- N- (2-Furylmethyl)-2-Thioxoacetamide

Y. Kobayashi-Matsunaga, T. Ishii, T. Hamaguchi, H. Osada and M. Sato

 

The synthesis and biological activities of a series of 2-amino-2-thioxoacetamide derivatives are described. These compounds have inhibitory effects against the protein tyrosine phosphatase activity of CD45. Compound 4i inhibited the PCA reaction in vivo.

 

[Back to top] Expression of a6b4 and a3b1 Integrins in Bullous Pemphigoid and Pemphigus Vulgaris

G. Giannelli, C. Foti, C. Divella, F. Marinosci, D. Bonamonte and S. Antonaci

 

Bullous pemphigoid and pemphigus vulgaris are blistering diseases. Our results show that expression of the integrins a6b4 a3b1is altered in both diseases: a6b4 to a greater extent in the former and a3b1 in the latter disease, respectively. Instead, the extracellular matrix examined resulted normally expressed.

 

[Back to top] Molecular Modeling for Quantitative Analysis of Molecular Interaction

Toshihiko Hanai

 

The binding affinity (log nK) between human serum albumin and acidic drugs was quantitatively analyzed using a computational chemical method with several model phases. A flat guanidino-phase was the most efficient for calculating log nK values, and docking was easily performed. A flowerpot type model phase bonded a guanidine group at the center bottom demonstrating that ion-ion interaction was the main driving force. A large molecule pushed aside the hydrophobic wall of log P = 5, and reached the guanidino group. Ionized acidic compounds may reach the guanidino group inside a protein by ion-ion interaction through a narrow channel of length 10Å.

 

[Back to top] Ascorbic Acid as Modulator of Immune Function in Sepsis

V.M. Victor

 

Oxidative stress is a major contributing factor to high mortality rates associated with several diseases such as sepsis. This condition can be controlled to a certain degree by antioxidants for instance ascorbic acid (vitamin C). This review focuses on the potential treatment of sepsis by ascorbic acid and its effects on the immune cell function.

 

[Back to top] Difficulties in the Management of Frontal Dementia: Therapeutics Strategies

Rita Moretti, Paola Torre, Rodolfo M. Antonello, Tatiana Cattaruzza and Giuseppe Cazzato

 

Frontal dementia gives rise to characteristic behavioral changes, which include altered emotions, profound alterations in personality and social conduct, and behavioral alterations constitute core and supportive symptoms laid out in the diagnostic criteria. There are some behavioral symptoms which are considered specific for frontal dementia, being present in at least 50% of cases. These includes loss of basic emotions and social embarrassment, selfishness, disinhibition, irritability, neglect, apathy, altered preference for sweet foods, with a tendency to continue eating for as long as food is present, or to steal food from other’s plates, motor and verbal stereotypies, wandering, and an absence of insightfulness. Albeit anatomical pathways are well known, there is no known therapy to prevent the advance of frontal dementia. The circuits involve a number of transmitters, receptor subtypes, and second messengers that can be potentially mediated pharmacologically. Though, rational treatments are currently limited. We present the possible actual and future therapeutic choices on the basis of anatomical and biochemical substrates.

 

[Back to top] Design of a New Phosphate Binder, Anion Exchange Resin, Based on Microcalorimeter Measurements

Hiroyoshi Inoue and Sho-ichi Yamagishi

 

It has been suggested that resin wettability is advantageous for dietary phosphate binding in the gastrointestinal tract. To evaluate the effect of anion exchange resin wetting properties on in vivo phosphate binding ability, four types of ethylene glycol dimethacrylate cross-linking 4-vinylpyridinium anion exchange resins (EGDMA-4VP) were synthesized.