Searching for New Leads To Treat Epilepsy: Target-Based Virtual Screening for the Discovery of Anticonvulsant Agents.

The purpose of this investigation is to contribute to the development of new anticonvulsant drugs to treat patients with refractory epilepsy. We applied a virtual screening protocol that involved the search into molecular databases of new compounds and known drugs to find small molecules that interact with the open conformation of the Nav1.2 pore. As the 3D structure of human Nav1.2 is not available, we first assembled 3D models of the target, in closed and open conformations. After the virtual screening, the resulting candidates were submitted to a second virtual filter, to find compounds with better chances of being effective for the treatment of P-glycoprotein (P-gp) mediated resistant epilepsy. Again, we built a model of the 3D structure of human P-gp, and we validated the docking methodology selected to propose the best candidates, which were experimentally tested on Nav1.2 channels by patch clamp techniques and in vivo by the maximal electroshock seizure (MES) test. Patch clamp studies allowed us to corroborate that our candidates, drugs used for the treatment of other pathologies like Ciprofloxacin, Losartan, and Valsartan, exhibit inhibitory effects on Nav1.2 channel activity. Additionally, a compound synthesized in our lab, N, N'-diphenethylsulfamide, interacts with the target and also triggers significant Na1.2 channel inhibitory action. Finally, in vivo studies confirmed the anticonvulsant action of Valsartan, Ciprofloxacin, and N, N'-diphenethylsulfamide.

[Admission, discharge and triage guidelines for paediatric intensive care units in Spain]. / Guias de ingreso, alta y triage para las unidades de cuidados intensivos pediátricos en España.

A paediatric intensive care unit (PICU) is a separate physical facility or unit specifically designed for the treatment of paediatric patients who, because of the severity of illness or other life-threatening conditions, require comprehensive and continuous inten-sive care by a medical team with special skills in paediatric intensive care medicine. Timely and personal intervention in intensive care reduces mortality, reduces length of stay, and decreases cost of care. With the aim of defending the right of the child to receive the highest attainable standard of health and the facilities for the treatment of illness and rehabilitation, as well as ensuring the quality of care and the safety of critically ill paediatric patients, the Spanish Association of Paediatrics (AEP), Spanish Society of Paediatric Intensive Care (SECIP) and Spanish Society of Critical Care (SEMICYUC) have approved the guidelines for the admission, discharge and triage for Spanish PICUs. By using these guidelines, the performance of Spanish paediatric intensive care units can be optimised and paediatric patients can receive the appropriate level of care for their clinical condition.

Guías de ingreso, alta y triage para las unidades de cuidados intensivos pediátricos en España / Admission, discharge and triage guidelines for paediatric intensive care units in Spain

La unidad de cuidados intensivos pediátricos (UCIP) es una unidad física asistencial hospitalaria independiente especialmente diseñada para el tratamiento de pacientes pediátricos quienes debido su gravedad o condiciones potencialmente letales requieren observación y asistencia médica intensiva integral y continua por un equipo médico que haya obtenido competencia especial en medicina intensiva pediátrica. La aplicación oportuna de terapia intensiva a los pacientes críticos reduce la mortalidad, el tiempo de estancia y los costes asistenciales. Con los objetivos de respetar el derecho del niño al disfrute del más alto nivel posible de salud y a servicios para el tratamiento de las enfermedades y la rehabilitación de la salud y de garantizar la calidad asistencial y la seguridad de los pacientes pediátricos críticos, la Asociación Española de Pediatría (AEP), la Sociedad Española de Cuidados Intensivos Pediátricos (SECIP) y la Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias (SEMICYUC) han desarrollado y aprobado las guías de ingreso, alta y triage para las UCIP en España. Mediante la aplicación de estas guías se puede optimizar el uso de las UCIP españolas de forma que los pacientes pediátricos reciban el nivel de cuidados médicos más apropiado para su situación clínica

A paediatric intensive care unit (PICU) is a separate physical facility or unit specifically designed for the treatment of paediatric patients who, because of the severity of illness or other life-threatening conditions, require comprehensive and continuous intensive care by a medical team with special skills in paediatric intensive care medicine. Timely and personal intervention in intensive care reduces mortality, reduces length of stay, and decreases cost of care. With the aim of defending the right of the child to receive the highest attainable standard of health and the facilities for the treatment of illness and rehabilitation, as well as ensuring the quality of care and the safety of critically ill paediatric patients, the Spanish Association of Paediatrics (AEP), Spanish Society of Paediatric Intensive Care (SECIP) and Spanish Society of Critical Care (SEMICYUC) have approved the guidelines for the admission, discharge and triage for Spanish PICUs. By using these guidelines, the performance of Spanish paediatric intensive care units can be optimised and paediatric patients can receive the appropriate level of care for their clinical condition

Guias de ingreso, alta y triage para las unidades de cuidados intensivos pediátricos en España / Admission, discharge and triage guidelines for paediatric intensive care units in Spain

La unidad de cuidados intensivos pediátricos (UCIP) es una unidad física asistencial hospitalaria independiente especialmente diseñada para el tratamiento de pacientes pediátricos quienes debido su gravedad o condiciones potencialmente letales requieren observación y asistencia médica intensiva integral y continua por un equipo médico que haya obtenido competencia especial en medicina intensiva pediátrica. La aplicación oportuna de terapia intensiva a los pacientes críticos reduce la mortalidad, el tiempo de estancia y los costes asistenciales. Con los objetivos de respetar el derecho del niño al disfrute del más alto nivel posible de salud y a servicios para el tratamiento de las enfermedades y la rehabilitación de la salud y de garantizar la calidad asistencial y la seguridad de los pacientes pediátricos críticos, la Asociación Española de Pediatría (AEP), la Sociedad Española de Cuidados Intensivos Pediátricos (SECIP) y la Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias (SEMICYUC) han desarrollado y aprobado las guías de ingreso, alta y triage para las UCIP en España. Mediante la aplicación de estas guías se puede optimizar el uso de las UCIP españolas de forma que los pacientes pediátricos reciban el nivel de cuidados médicos más apropiado para su situación clínica

A paediatric intensive care unit (PICU) is a separate physical facility or unit specifically designed for the treatment of paediatric patients who, because of the severity of illness or other life-threatening conditions, require comprehensive and continuous inten-sive care by a medical team with special skills in paediatric intensive care medicine. Timely and personal intervention in intensive care reduces mortality, reduces length of stay, and decreases cost of care. With the aim of defending the right of the child to receive the highest attainable standard of health and the facilities for the treatment of illness and rehabilitation, as well as ensuring the quality of care and the safety of critically ill paediatric patients, the Spanish Association of Paediatrics (AEP), Spanish Society of Paediatric Intensive Care (SECIP) and Spanish Society of Critical Care (SEMICYUC) have approved the guidelines for the admission, discharge and triage for Spanish PICUs. By using these guidelines, the performance of Spanish paediatric intensive care units can be optimised and paediatric patients can receive the appropriate level of care for their clinical condition

Admission, discharge and triage guidelines for paediatric intensive care units in Spain. / Guias de ingreso, alta y triage para las unidades de cuidados intensivos pediátricos en España.

A paediatric intensive care unit (PICU) is a separate physical facility or unit specifically designed for the treatment of paediatric patients who, because of the severity of illness or other life-threatening conditions, require comprehensive and continuous inten-sive care by a medical team with special skills in paediatric intensive care medicine. Timely and personal intervention in intensive care reduces mortality, reduces length of stay, and decreases cost of care. With the aim of defending the right of the child to receive the highest attainable standard of health and the facilities for the treatment of illness and rehabilitation, as well as ensuring the quality of care and the safety of critically ill paediatric patients, the Spanish Association of Paediatrics (AEP), Spanish Society of Paediatric Intensive Care (SECIP) and Spanish Society of Critical Care (SEMICYUC) have approved the guidelines for the admission, discharge and triage for Spanish PICUs. By using these guidelines, the performance of Spanish paediatric intensive care units can be optimised and paediatric patients can receive the appropriate level of care for their clinical condition.

N-propyl-2,2-diphenyl-2-hydroxyacetamide, a novel α-hydroxyamide with anticonvulsant, anxiolytic and antidepressant-like effects that inhibits voltage-gated sodium channels.

In patients with epilepsy, anxiety and depression are the most frequent psychiatric comorbidities but they often remain unrecognized and untreated. We report herein the antidepressant-like activity in two animal models, tail suspension and forced swimming tests, of six anticonvulsants α-hydroxyamides. From these, N-propyl-2,2-diphenyl-2-hydroxyacetamide (compound 5) emerged not only as the most active as anticonvulsant (ED50 = 2.5mg/kg, MES test), but it showed the most remarkable antidepressant-like effect in the tail suspension and forced swimming tests (0.3-30mg/kg, i.p.); and, also, anxiolytic-like action in the plus maze test (3-10mg/kg, i.p.) in mice. Studies of its mechanism of action, by means of its capacity to act via the GABAA receptor ([3H]-flunitrazepam binding assay); the 5-HT1A receptor ([3H]-8-OH-DPAT binding assay) and the voltage-gated sodium channels (either using the patch clamp technique in hNav 1.2 expressed in HEK293 cell line or using veratrine, in vivo) were attempted. The results demonstrated that its effects are not likely related to 5-HT1A or GABAAergic receptors and that its anticonvulsant and antidepressant-like effect could be due to its voltage-gated sodium channel blocking properties.

Propylparaben applied after pilocarpine-induced status epilepticus modifies hippocampal excitability and glutamate release in rats.

Propylparaben (PPB) induces cardioprotection after ischemia-reperfusion injury by inhibiting voltage-dependent Na+ channels. The present study focuses on investigating whether the i.p. application of 178mg/kg PPB after pilocarpine-induced status epilepticus (SE) reduces the acute and long-term consequences of seizure activity. Initially, we investigated the effects of a single administration of PPB after SE. Our results revealed that compared to rats receiving diazepam (DZP) plus vehicle after 2h of SE, animals receiving a single dose of PPB 1h after DZP injection presented 126% (p<0.001) lower extracellular levels of glutamate in the hippocampus. This effect was associated with an increased potency of low-frequency oscillations (0.1-13Hz bands, p<0.001), a reduced potency of 30-250Hz bands (p<0.001) and less neuronal damage in the hippocampus. The second experiment examined whether the subchronic administration of PPB during the post-SE period is able to prevent the long-term consequences of seizure activity. In comparison to animals that were treated subchronically with vehicle after SE, rats administered with PPB for 5 days presented lower hippocampal excitability and interictal glutamate release, astrogliosis, and neuroprotection in the dentate gyrus. Our data indicate that PPB, when applied after SE, can be used as a therapeutic strategy to reduce the consequences of seizure activity.

Anticonvulsant effect of sodium cyclamate and propylparaben on pentylenetetrazol-induced seizures in zebrafish.

Screening for novel anticonvulsant drugs requires appropriate animal seizure models. Zebrafish provide small, accessible, and cost-efficient preclinical models applicable to high-throughput small molecule screening. Based on previous results in rodents, we have here examined the effects of artificial sweetener sodium cyclamate and antimicrobial agent sodium propylparaben on a model of pentylenetetrazole (PTZ)-induced seizures in zebrafish. Sodium cyclamate reduced the bursts of hyperactivity, the spasms, increased the latency to spasms, and the latency to seizure, while propylparaben increased the latency to spasms. The results show the potential of zebrafish to detect novel anticonvulsant compounds while they also demonstrate the ability of two commonly ingested chemical compounds to modify the seizure threshold when were administrated at low concentration.

New model of pharmacoresistant seizures induced by 3-mercaptopropionic acid in mice.

About 30% of the patients with epilepsy do not respond to clinically established anticonvulsants, despite having effective concentrations of the antiepileptic drug in plasma. Therefore, new preclinical models of epilepsy are needed to identify more efficacious treatments. We describe here a new drug-resistant seizure model in mice to be used at the early stages of pre-clinical trials. This model consists in inducing daily generalized seizures for 23 consecutive days by administration of 3-mercaptopropionic acid (MP). As a result, 100% of animals become resistant to phenytoin and 80% to phenobarbital. Such resistance is strongly associated with the overexpression of P-glycoprotein (Pgp), observed in cerebral cortex, hippocampus and striatum while resistance to Pgp nonsubstrate drugs such as carbamazepine, diazepam and levetiracetam is not observed. This model could be useful for screening novel anticonvulsant drugs with a potential effect on pharmacoresistant seizures treatment.

Computer-Aided Recognition of ABC Transporters Substrates and Its Application to the Development of New Drugs for Refractory Epilepsy.

Despite the introduction of more than 15 third generation antiepileptic drugs to the market from 1990 to the moment, about one third of the epileptic patients still suffer from refractory to intractable epilepsy. Several hypotheses seek to explain the failure of drug treatments to control epilepsy symptoms in such patients. The most studied one proposes that drug resistance might be related with regional overactivity of efflux transporters from the ATP-Binding Cassette (ABC) superfamily at the blood-brain barrier and/or the epileptic foci in the brain. Different strategies have been conceived to address the transporter hypothesis, among them inhibiting or down-regulating the efflux transporters or bypassing them through a diversity of artifices. Here, we review scientific evidence supporting the transporter hypothesis along with its limitations, as well as computer-assisted early recognition of ABC transporter substrates as an interesting strategy to develop novel antiepileptic drugs capable of treating refractory epilepsy linked to ABC transporters overactivity.

Novel sulfamides and sulfamates derived from amino esters: Synthetic studies and anticonvulsant activity.

We report herein the design and optimization of a novel series of sulfamides and sulfamates derived from amino esters with anticonvulsant properties. The structures were designed based on the pharmacophoric pattern previously proposed, with the aim of improving the anticonvulsant action. The compounds were obtained by a new synthetic procedure with microwave assisted heating and the use of adsorbents in the isolation process. All the derivatives showed protection against the maximal electroshock seizure test (MES test) in mice at the lowest dose tested (30 mg/kg) but they did not show significant protection against the chemical induced convulsion by pentylenetetrazole. These results verify the ability of the computational model for designing new anticonvulsants structures with anti-MES activity. Additionally, we evaluated the capacity of the synthesized structures to bind to the benzodiazepine binding site (BDZ-bs) of the γ-aminobutiric acid receptor (GABAA receptor). Some of them showed medium to low affinity for the BDZ-bs.

Sulfamide derivatives with selective carbonic anhydrase VII inhibitory action.

A set of N,N'-disubstituted sulfamides and sodium cyclamate have been tested for their inhibitory action against six isoforms of carbonic anhydrase (CA, EC 4.2.1.1) found in the brain, that is, CA I, CA II, CA VII, CA IX, CA XII and CA XIV, some of which are involved in epileptogenesis. The biological data showed interesting results for CA VII inhibition, the isozyme thought to be a novel antiepileptic target. Strong CA VII inhibitors, with Ki values in the low nanomolar-subnanomolar range were identified. Some of these derivatives showed selectivity for inhibition of CA VII versus the ubiquitous isoform CA II, for which the Ki values were in the micromolar range. Molecular modeling approaches were employed to understand the binding interactions between these compounds and the two CA isoforms, since the mechanism of action of such disubstituted sulfamides was not yet investigated by means of X-ray crystallography.

Computer-Aided Identification of Anticonvulsant Effect of Natural Nonnutritive Sweeteners Stevioside and Rebaudioside A.

Steviol glycosides are natural constituents of Stevia rebaudiana (Bert.) Bert. (Asteraceae) that have recently gained worldwide approval as nonnutritive sweeteners by the Joint Food and Agriculture Organization/World Organization Expert Committee on Food Additives. Cheminformatic tools suggested that the aglycone steviol and several of its phase I metabolites were predicted as potential anticonvulsant agents effective in the seizure animal model maximal electroshock seizure (MES) test. Thus, aqueous infusion from S. rebaudiana was tested in the MES test (mice, intraperitoneal administration), confirming dose-dependent anticonvulsant effect. Afterward, isolated stevioside and rebaudioside A were tested in the MES test, with positive results. Though drug repositioning most often focuses on known therapeutics, this article illustrates the possibilities of this strategy to find new functionalities and therapeutic indications for food constituents and natural products.

Is there a relationship between sweet taste and seizures? Anticonvulsant and proconvulsant effects of non-nutritive sweeteners.

From a virtual screening campaign, a number of artificial and natural sweeteners were predicted as potential anticonvulsant agents with protective effects in the seizure animal model Maximal Electroshock Seizure (MES) test. In all cases, the predictions were experimentally confirmed in the aforementioned preclinical seizure model. The article reviews and expands previous reports from our group on anticonvulsant activity of those non-nutritive sweeteners, illustrating the potential of virtual screening approaches to propose new medical uses of food additives. This constitutes a particular case of knowledge-based drug repositioning, which may greatly shorten the development time and investment required to introduce novel medications to the pharmaceutical market. We also briefly overview evidence on possible molecular explanations on the anticonvulsant and proconvulsant effects of different non-nutritive sweeteners. Our analysis -based on Swanson's ABC model- suggests that group I metabotropic glutamate receptors and carbonic anhydrase isoform VII (both proposed or validated molecular targets of antiepileptic drugs) might be involved in the anticonvulsant effect of artificial sweeteners. The first hypothesis is in line with recent advances on development of selective modulators of group I metabotropic glutamate receptors as potential antiepileptic agents.

Systematic Comparison of the Performance of Different 2D and 3D Ligand-Based Virtual Screening Methodologies to Discover Anticonvulsant Drugs.

Virtual screening encompasses a wide range of computational approaches aimed at the high-throughput, cost-efficient exploration of chemical libraries or databases to discover new bioactive compounds or novel medical indications of known drugs. Here, we have performed a systematic comparison of the performance of a large number of 2D and 3D ligand-based approaches (2D and 3D similarity, QSAR models, pharmacophoric hypothesis) in a simulated virtual campaign on a chemical library containing 50 known anticonvulsant drugs and 950 decoys with no previous reports of anticonvulsant effect. To perform such comparison, we resorted to Receiver Operating Characteristic curves. We also tested the relative performance of consensus methodologies. Our results indicate that the selective combination of the individual approaches (through voting and ranking combination schemes) significantly outperforms the individual algorithms and/or models. Among the best-performing individual approaches, 2D similarity search based on circular fingerprints and 3D similarity approaches should be highlighted. Combining the results from different query molecules also led to enhanced enrichment.

Computer-guided drug repurposing: identification of trypanocidal activity of clofazimine, benidipine and saquinavir.

In spite of remarkable advances in the knowledge on Trypanosoma cruzi biology, no medications to treat Chagas disease have been approved in the last 40 years and almost 8 million people remain infected. Since the public sector and non-profit organizations play a significant role in the research efforts on Chagas disease, it is important to implement research strategies that promote translation of basic research into the clinical practice. Recent international public-private initiatives address the potential of drug repositioning (i.e. finding second or further medical uses for known-medications) which can substantially improve the success at clinical trials and the innovation in the pharmaceutical field. In this work, we present the computer-aided identification of approved drugs clofazimine, benidipine and saquinavir as potential trypanocidal compounds and test their effects at biochemical as much as cellular level on different parasite stages. According to the obtained results, we discuss biopharmaceutical, toxicological and physiopathological criteria applied to decide to move clofazimine and benidipine into preclinical phase, in an acute model of infection. The article illustrates the potential of computer-guided drug repositioning to integrate and optimize drug discovery and preclinical development; it also proposes rational rules to select which among repositioned candidates should advance to investigational drug status and offers a new insight on clofazimine and benidipine as candidate treatments for Chagas disease. One Sentence Summary: We present the computer-guided drug repositioning of three approved drugs as potential new treatments for Chagas disease, integrating computer-aided drug screening and biochemical, cellular and preclinical tests.

Docking applied to the prediction of the affinity of compounds to P-glycoprotein.

P-glycoprotein (P-gp) is involved in the transport of xenobiotic compounds and responsible for the decrease of the drug accumulation in multi-drug-resistant cells. In this investigation we compare several docking algorithms in order to find the conditions that are able to discriminate between P-gp binders and nonbinders. We built a comprehensive dataset of binders and nonbinders based on a careful analysis of the experimental data available in the literature, trying to overcome the discrepancy noticeable in the experimental results. We found that Autodock Vina flexible docking is the best choice for the tested options. The results will be useful to filter virtual screening results in the rational design of new drugs that are not expected to be expelled by P-gp.

A synthetic bioisoster of trimethadione and phenytoin elicits anticonvulsant effect, protects the brain oxidative damage produced by seizures and exerts antidepressant action in mice.

Epilepsy is recognized as one of the most common and serious neurological disorder affecting 1-2% of the world׳s population. The present study demonstrates that systemic administration of 3-butyl-5,5-dimethyl-1,2,3-oxathiazolidine-4-one-2,2-dioxide (DIOXIDE), a synthetic compound bioisoster of trimethadione and phenytoin (classical anticonvulsants), elicits a dose dependent anticonvulsant response in mice submitted to the subcutaneous pentylenetetrazole seizure test (scPTZ). Among various factors supposed to play role in epilepsy, oxidative stress and reactive species have strongly emerged. The protection exerted by DIOXIDE over the extent of brain oxidative damage produced by PTZ was determined, by measuring the levels of lipid peroxidation and reduced glutathione and the activity of Na(+)/K(+)-ATPase. Psychiatric disorders represent frequent comorbidities in persons with epilepsy. In this report, the potential anxiolytic and antidepressant activities of DIOXIDE were evaluated in several widely used models for assessing anxiolytic and antidepressant activities in rodents. Although DIOXIDE did not evidence anxiolytic activity at the doses tested, it revealed a significant antidepressant-like effect. Preliminary studies of its mechanism of action, by means of its capacity to act via the GABAA receptor (using the [(3)H]flunitrazepam binding assay in vitro and the picrotoxin test in vivo) and the Na(+) channel (using the alkaloid veratrine, a voltage-Na(+) channel agonist) demonstrated that the anticonvulsant effect is not likely related to the GABAergic pathway and the antidepressant-like effect could be due to its Na(+) channel blocking properties. The results for DIOXIDE suggested it as a new anticonvulsant-antioxidant and antidepressant compound that deserves further development.

Targeting a cross-reactive Gly m 5 soy peptide as responsible for hypersensitivity reactions in a milk allergy mouse model.

BACKGROUND: Cross-reactivity between soybean allergens and bovine caseins has been previously reported. In this study we aimed to map epitopes of the major soybean allergen Gly m 5 that are co-recognized by casein specific antibodies, and to identify a peptide responsible for the cross-reactivity. METHODS: Cow's milk protein (CMP)-specific antibodies were used in different immunoassays (immunoblotting, ELISA, ELISA inhibition test) to evaluate the in vitro recognition of soybean proteins (SP). Recombinant Gly m 5 (α), a truncated fragment containing the C-terminal domain (α-T) and peptides of α-T were obtained and epitope mapping was performed with an overlapping peptide assay. Bioinformatics tools were used for epitope prediction by sequence alignment, and for modelling the cross-recognized soy proteins and peptides. The binding of SP to a monoclonal antibody was studied by surface Plasmon resonance (SPR). Finally, the in vivo cross-recognition of SP was assessed in a mouse model of milk allergy. RESULTS: Both α and α-T reacted with the different CMP-specific antibodies. α-T contains IgG and IgE epitopes in several peptides, particularly in the peptide named PA. Besides, we found similar values of association and dissociation constants between the α-casein specific mAb and the different milk and soy components. The food allergy mouse model showed that SP and PA contain the cross-reactive B and T epitopes, which triggered hypersensitivity reactions and a Th2-mediated response on CMP-sensitized mice. CONCLUSIONS: Gly m 5 is a cross-reactive soy allergen and the α-T portion of the molecule contains IgG and IgE immunodominant epitopes, confined to PA, a region with enough conformation to be bound by antibodies. These findings contribute to explain the intolerance to SP observed in IgE-mediated CMA patients, primarily not sensitised to SP, as well as it sets the basis to propose a mucosal immunotherapy for milk allergy using this soy peptide.

Development of conformation independent computational models for the early recognition of breast cancer resistance protein substrates.

ABC efflux transporters are polyspecific members of the ABC superfamily that, acting as drug and metabolite carriers, provide a biochemical barrier against drug penetration and contribute to detoxification. Their overexpression is linked to multidrug resistance issues in a diversity of diseases. Breast cancer resistance protein (BCRP) is the most expressed ABC efflux transporter throughout the intestine and the blood-brain barrier, limiting oral absorption and brain bioavailability of its substrates. Early recognition of BCRP substrates is thus essential to optimize oral drug absorption, design of novel therapeutics for central nervous system conditions, and overcome BCRP-mediated cross-resistance issues. We present the development of an ensemble of ligand-based machine learning algorithms for the early recognition of BCRP substrates, from a database of 262 substrates and nonsubstrates compiled from the literature. Such dataset was rationally partitioned into training and test sets by application of a 2-step clustering procedure. The models were developed through application of linear discriminant analysis to random subsamples of Dragon molecular descriptors. Simple data fusion and statistical comparison of partial areas under the curve of ROC curves were applied to obtain the best 2-model combination, which presented 82% and 74.5% of overall accuracy in the training and test set, respectively.