Synthesis and anticonvulsant evaluation of<Emphasis Type="Italic">N-Cbz</Emphasis>-α-amino-<Emphasis Type="Italic">N</Emphasis>-alkoxysuccinimides

In previous studies for the development of new anticonvulsants, we found that N-Cbz-alpha-amino-N-alkylsuccinimides exhibited significant anticonvulsant activities in the Maximal electroshock seizure (MES) and Pentylenetetrazole induced seizure (PTZ) tests, and also their anticonvulsant activities were dependent on the N-alkyl substituents existent in their structures. Based on these estimations, N-Cbz-alpha-amino-N-hydroxysuccinimide and various N-Cbz-alpha-amino-N-alkoxysuccinimides were prepared in order to develop more active anticonvulsants and to examine the effects of N-hydoxy or N-alkoxy groups on their anticonvulsant activities. The (R)- or (S)-N-Cbz-alpha-amino-N-hydroxysuccinimide and N-Cbz-alpha-amino-N-alkoxysuccinimides were prepared from the corresponding (R)- or (S)-N-Cbz-aspartic acid through the known synthetic procedures. Their anticonvulsant activities in the MES and PTZ test were evaluated. All of these compounds except 3a showed significant anticonvulsant activities against the PTZ test, but these compounds were not active in the MES test. The most active compound in the PTZ test was (R)-N-Cbz-alpha-amino-N-benzyloxysuccinimide (ED50=62.5 mg/kg). In addition, the anticonvulsant activities of these compounds were dependent on their N-substited groups. The order of anticonvulsant activity against the PTZ test, as judged from the ED50 values for (R) series was N-benzyloxy > N-hydroxy > N-isopropoxy > N-methoxy > N-ethoxy; for the (S) series N-ethoxy > N-benzyloxy > N-methoxy > N-isopropoxy.     

Synthesis and anticonvulsant activities ofN-Cbz-α-aminoglutarimidooxy carboxylate derivatives

Previous studies on the anticonvulsant activity of N-Cbz-alpha-aminoglutarimides have shown that the derivatives of N-Cbz-alpha-amino-N-alkoxy glutarimide have significant anticonvulsant activity. In addition, their anticonvulsant activities are dependent on the presence of N-alkoxy groups. Based on these results, a series of N-Cbz-alpha-amino-glutarimidooxy carboxylates derivatives (3a-e) were synthesized in moderate yield using a known synthetic procedure. Their anticonvulsant activities were evaluated using the maximal electroshock seizure (MES) test, the pentylene tetrazole induced seizure (PTZ) test, and the strychinine (Str) threshold test with the ultimate aim of developing more active anticonvulsants. None of the compounds (3a-e) tested showed anticonvulsant activity in the MES and PTZ test. However, all the compounds tested exhibited significant anticonvulsant activity in the Str. test. The most active compound in the Str. test was the methyl ester of N-Cbz-alpha-amino-glutarimidooxy acetic acid 3a (ED50 = 42.9 mg/kg).     

Synthesis and Anticonvulsant Evaluations ofN-Cbz-α-amino-N-alkoxyglutarimides

In our previous studies for the development of new anticonvulsant of broad spectrum, we found that N-cbz-alpha-aminoglutarimides showed significant anticonvulsant activities of broad spectrum enough to be recommended for the new anticonvulsants and their anticonvulsant activities were dependent on their imide substituent groups. Based on these results, various N-cbz-alpha-amino-N-alkoxyglutarimides, where the imide N-H was substituted with the hydroxy and alkoxy group, were prepared and evaluated for their anticonvulsant activities using the Maximal electroshock seizure (MES) and Pentylenetetrazole induced seizure (PTZ) tests and also the rotorod test. A series of (R) or (S)-N-cbz-alpha-amino-N-alkoxyglutarimides could be prepared from the corresponding (R) or (S)-N-cbz-glutamic acid following the usual synthetic procedure. Among them, (R)-N-cbz-alpha-amino-N-hydroxyglutarimide (ED50=86.25 mg/kg) was most active in the MES test. In the case of the PTZ test, (R)-N-cbz-alpha-amino-N-benzyloxyglutarimide (ED50=62.5 mg/kg) was most active. Among the tested compounds, 2a-c, 3a, and 3b showed anticonvulsant activities in the MES and PTZ test. All of the tested compounds, except 2f and 3f, showed significant anticonvulsant activities in the MES or PTZ test. In addition, the neurotoxicities of these compounds were comparable to other anticonvulsant drugs.     

Synthesis and anticonvulsant evaluation of 6-amino-1,4-oxazepane-3,5-dione derivatives

The N-Acyl-alpha-aminosuccinimides and N-Acyl-alpha-aminoglutarimides were reported to exhibit moderate anticonvulsant activities. These compounds were 5-membered or 6-membered alpha-amino cyclic imides and have N-CO-C-N moiety in their structures. Based on these structural characteristics, a series of 6-amino-1,4-oxazepine-3,5-dione derivatives 1, having a heterocyclic 7-memberd alpha-amino cyclic imide and N-CO-C-N moiety in their structures were designed and synthesized. These syntheses were in view to develop novel anticonvulsant compounds. The 6-amino-1, 4-oxazepine-3,5-dione derivatives were prepared from (S)-N-Cbz-serine by usual synthetic procedures and their anticonvulsant activities were examined by the MES and PTZ tests. The N-H (1a), N-methyl (1b), and N-n-butyl (1e) derivatives showed moderate anticonvulsant activities in the MES test. In the case of PTZ test, all the tested compounds except N-n-propyl compound(1c) also showed moderate anticonvulsant activities. Moreover, N-H (1a), N-methyl (1b), and N-n-butyl (1e) derivatives showed anticonvulsant activities in both the MES and PTZ test. From these studies, it was concluded that the 6-amino-1,4-oxazepane-3,5-dione derivatives were novel compounds enough to be recommended as new anticonvulsants.     

Anticonvulsant activity of p-chlorophenyl substituted arylsemicarbazones--the role of primary terminal amino group

A series of p-chlorophenyl substituted arylsemicarbazones were synthesized and evaluated for anticonvulsant activity. Most of the compounds provided significant protection against maximal electroshock-induced seizures (MES) at 100 mg/kg after 0.5 h and at 300 mg/kg after 4 h in both MES and pentetrazole-induced (PTZ) seizures. In the strychnine-induced seizures (scSTY), the majority of the compounds showed protection at 30 mg/kg. The compound 2 was active in both MES and PTZ tests. The study has shown that the terminal primary amino group is not necessary for anticonvulsant activity.     

Differential contribution of GABA(A) receptor subtypes to the anticonvulsant efficacy of benzodiazepine site ligands

Non-selective benzodiazepines, such as diazepam, interact with equivalent affinity and agonist efficacy at GABA(A) receptors containing either an alpha1, alpha2, alpha3 or alpha5 subunit. However, which of these particular subtypes are responsible for the anticonvulsant effects of diazepam remains uncertain. In the present study, we examined the ability of diazepam to reduce pentylenetetrazoLe (PTZ)-induced and maximal electroshock (MES)-induced seizures in mice containing point mutations in single (alpha1H101R, alpha2H101R or alpha5H105R) or multiple (alpha125H-->R) alpha subunits that render the resulting GABA(A) receptors diazepam-insensitive. Furthermore, the anticonvulsant properties of diazepam, the alpha1- and alpha3-selective compounds zolpidem and TP003, respectively, and the alpha2/alpha3 preferring compound TP13 were studied against PTZ-induced seizures. In the transgenic mice, no single subtype was responsible for the anticonvulsant effects of diazepam in either the PTZ or MES assay and neither the alpha3 nor alpha5 subtypes appeared to confer anticonvulsant activity. Moreover, whereas the alpha1 and alpha2 subtypes played a modest role with respect to the PTZ assay, they had a negligible role in the MES assay. With respect to subtype-selective compounds, zolpidem and TP003 had much reduced anticonvulsant efficacy relative to diazepam in both the PTZ and MES assays whereas TP13 had high anticonvulsant efficacy in the PTZ but not the MES assay. Taken together, these data not only indicate a role for alpha2-containing GABA(A) receptors in mediating PTZ and MES anticonvulsant activity but also suggest that efficacy at more than one subtype is required and that these subtypes act synergistically.     

Synthesis and Anticonvulsant Activity Evaluation of 5‐Phenyl‐[1,2,4]triazolo[4,3‐c]quinazolin‐3‐amines

In the present study we describe the syntheses and anticonvulsant activity evaluation of 5‐phenyl‐[1,2,4]triazolo[4,3‐c]quinazolin‐3‐amine derivatives. Their anticonvulsant activity and neurotoxicity were evaluated by the maximal electroshock seizure test (MES) and the rotarod test, respectively. The majority of the compounds prepared were effective in the MES screens at a dose level of 100 mg/kg. Of these compounds, the most promising was compound 8h , which showed an ED₅₀ value of 27.4 mg/kg and a protective index (PI) value of 5.8. These values were superior to those provided by valproate (ED₅₀ and PI values of 272 and 1.6, respectively) in the MES test in mice. As well as its anti‐MES efficacy, the potencies of compound 8h against seizures induced by pentylenetetrazole and thiosemicarbazide were also established, with the results suggesting that the GABAergic system‐mediated mechanisms might be involved in its anticonvulsant activity.     

Synthesis and evaluation of anticonvulsant activities of 7‐phenyl‐4,5,6,7‐tetrahydrothieno[3,2‐b ]pyridine derivatives

A series of 7‐phenyl‐4,5,6,7‐tetrahydrothieno[3,2‐b]pyridine derivatives containing triazole and other heterocycle substituents (methyltriazole, tetrazole, and triazolone) is described. Two experimental methods, maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ), were used to evaluate the anticonvulsant activity of the target compounds. Moreover, the neurotoxicity (NT) was tested using the Rotarod test. 5‐(4‐Chlorophenyl)‐4,5‐dihydrothieno[2,3‐e][1,2,4]triazolo[4,3‐a]pyridine ( 6c ) showed the best anticonvulsant activity. In the MES and PTZ experiments, the 50% effective dose (ED₅₀) values of compound 6c were 9.5 and 20.5 mg/kg, respectively. From the therapeutic index (PI) values, 6c (MES and PTZ with PI values of 48.0 and 22.2, respectively) showed better safety than the clinical drugs carbamazepine (MES with PI value of 6.4) and ethosuximide (PTZ with PI value of 3.2). The biological activities of the compounds were verified by using molecular docking studies. Compound 6c showed significant interactions with residues at the benzodiazepine‐binding site on gamma‐aminobutyric acid A (GABA_A) receptors. The results of in vivo GABA estimation and bicuculline‐induced seizures showed that 6c may have an effect on the GABA system. The physicochemical and pharmacokinetic properties of the target compounds were predicted.     

Anticonvulsant properties of N-(4-methylpiperazin-1-yl)- and N-[3-(4-methyl-piperazin-1-yl)propyl] derivatives of 3-aryl- and 3-spirocycloalkyl-pyrrolidine-2,5-dione

Two series of N-(4-methylpiperazin-1-yl)- and N-[3-(4-methylpiperazin-1-yl)-propyl]-3-aryl- and 3-spirocycloalkyl-pyrrolidine-2,5-dione derivatives were synthesized and tested for anticonvulsant activity in the maximum electroshock (MES) seizure and pentetrazole (sc PTZ) seizure threshold tests. Compounds with an aromatic ring at position-3 of pyrrolidine-2,5-dione exhibited anticonvulsant activity in the MES test. For that series of compounds, ED50 values were determined. The most potent in the series were derivatives and with a chlorine atom at position-3 or 4 of the aromatic ring. Those compounds exhibited strong anticonvulsant activity, and their ED50 values ranged from 29 to 48 mg/kg. Introduction of the spirocycloalkyl ring into the position-3 of pyrrolidine-2,5-dione made those compounds inactive.     

Synthesis,anticonvulsant activity and QSAR studies of some new pyrazolyl pyridines

Twenty-one new 3,5-bipyridinyl-1H-pyrazole derivatives (pyrazolyl pyridines) have been synthesized and evaluated for their anticonvulsant activity in animal models of epilepsy. The pyrazolyl pyridines, 7–27, were obtained through a general one-pot synthesis, from ketones and acid chlorides via formation of 1,3-diketones in situ carried out in hydrocarbon solvent and LiHMDS base. The profile of anticonvulsant activity of final compounds was established in the maximal electroshock (MES) and subcutaneous pentylenetetrazole (sc PTZ) tests, after intraperitoneal injection in rats and mice, respectively, at doses of 30, 100, and 300 mg/kg. An observation was carried out at two different time intervals—0.5 and 4 h. Phenytoin was used as a standard antiepileptic against MES convulsions and valproic acid against sc PTZ convulsions. Furthermore, in addition to the primary anticonvulsant screening, the acute neurological toxicity was determined in mice by the rotarod test and in rats by positional sense test. The compounds showed anticonvulsant activity exclusively against MES convulsions. The compounds were found especially active in 100 mg/kg dose at both the time points, i.e., 0.5 and 4 h, depending upon the lipophilicity of molecules as indicated by statistically significant reduction in the time spent in tonic extension phase (p < 0.001). Further, the newly synthesized compounds were subjected to two-dimensional quantitative structure–activity relationship (2D QSAR) analysis through multiple linear regression, principal component regression, and partial least square regression analysis, and three-dimensional quantitative structure–activity relationship (3D QSAR) analysis by k-nearest neighbor molecular field analysis in conjunction with stepwise forward–backward, genetic algorithm, and simulated annealing variable selection methods using the software VLife MDS. The structure–activity relationship (SAR) as well as quantitative structure–activity relationship (QSAR) studies for anticonvulsant activity confirmed the crucial role of 3,5-bipyridinyl-1H-pyrazole core fragment for anticonvulsant activity.     

An experimental evaluation of anticonvulsant activity of Vitex-negundo

Maximal electroshock seizures (MES) in albino rats and pentylenetetarazole (PTZ) induced seizures in albino mice were used to study anticonvulsant activity of Vitex-negundo leaf extract. The ethanolic leaf extract of Vitex-negundo was administered orally in graded doses (250, 500 and 1000 mg/kg p.o) in both the experimental models and the effects were compared with diphenylhydantoin in MES method and valporic acid in PTZ induced seizures method as standard control respectively. The Vitex-negundo in the doses (250, 500 and 1000 mg/kg, p.o) did not show protection against MES to any significant extent but significant post-ictal depression was observed in the dose of 1000 mg/kg body weight in comparison to control. However, sub-protective dose of test drug (100 mg/ kg, p.o) potentiated the anticonvulsant action of diphenylhydantoin. The test drug in the dose (1000 mg/kg, po) showed 50% protection in clonic seizures and 24-hour mortality against PTZ induced seizures. It also decreased number and duration of convulsions significantly. Vitex-negundo potentiated anticonvulsant activity of valporic acid. The anticonvulsant activity of Vitex-negundo has not been found equi-effective with standard drugs. These findings suggest that Vitex-negundo possesses anticonvulsant activity particularly against PTZ induced convulsions. Moreover, the potentiation of diphenylhydantoin and valporic acid by Vitex-negundo indicates that it may be useful as an adjuvant therapy along with standard anticonvulsants and can possibly lower the requirement of diphenylhydantoin and valporic acid.     

Synthesis and anticonvulsant activities of 4-N-substituted arylsemicarbazones

A series of 4-N-substituted arylsemicarbazones with increased lipophilicity were synthesized and evaluated for anticonvulsant activity. The compounds provided significant protection against maximal electroshock induced seizures (MES) and seizures indicated by sc pentetrazole administration (sc PTZ) at 300 mg/kg after 0.5 h. The compounds 8 and 4 were active in MES and sc PTZ indicated seizure. The study has shown that introduction of alkyl (ethyl) at the terminal amino group and alkoxy (methoxy) moiety at the distal aryl ring led to increased activity and decreased toxicity.     

The effect ofN-substituted alkyl groups on anticonvulsant activities ofN-Cbz-α-amino-N-alkylglutarimides

In order to examine the effects of N-substituted alkyl group on the anticonvulsant activities of N-Cbz-alpha-aminoglutarimides as novel anticonvulsants with broad spectrum, a series of (R) or (S) N-Cbz-alpha-amino-N-alkylglutarimides (1 and 2) were prepared from the corresponding (R) or (S) N-Cbz-glutamic acid and evaluated for the anticonvulsant activities in the maximal electroshock seizure (MES) test and pentylenetetrazol induced seizure (PTZ) test, including the neurotoxicity. The most potent compound in the MES test was (S) N-Cbz-alpha-amino-N-methylglutarimide (ED50=36.3 mg/kg, PI=1.7). This compound was also most potent in the PTZ test (ED50=12.5 mg/kg, PI=5.0). The order of anticonvulsant activities against the MES test as evaluated from ED50 values for (R) series was N-methyl > N-H > N-ethyl > N-allyl; for the (S) series N-methyl > N-H > N-ethyl > N-allyl > N-isobutyl compound. Against the PTZ tests, the order of anticonvulsant activities showed similar pattern; for the (R) series, N-methyl > N-H > N-ethyl > N-allyl; for the (S) series N-methyl > N-H > N-ethyl > N-allyl > N-isobutyl compound. From the above results, N-substituted alkyl groups were thought to play an important role for the anticonvulsant activities of N-Cbz-alpha-amino-N-alkylglutarimides.     

Synthesis and anticonvulsant activity of new n-mannich bases derived from 5-cyclopropyl-5-phenyl-hydantoins

Synthesis, physicochemical and anticonvulsant properties of new N‐Mannich bases 3–24 derived from 5‐cyclopropyl‐5‐phenyl‐ and 5‐cyclopropyl‐5‐(4‐chlorophenyl)‐hydantoins were described here. Initial anticonvulsant screening was performed using intraperitoneal (i.p.) maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) seizures tests. Selected derivatives were also screened in the 6‐Hz test. The neurotoxicity was determined applying the rotorod test. The pharmacological results revealed that the majority of compounds were effective in MES and/or scPTZ tests. The quantitative studies after oral administration into rats showed that several molecules were more potent than phenytoin and ethosuximide which were used as reference antiepileptic drugs. From the whole series the most active was 3‐[(4‐phenylpiperazin‐1‐yl)‐methyl]‐5‐cyclopropyl‐5‐phenyl‐imidazolidine‐2,4‐dione ( 3 ) with the ED₅₀ value of 5.29 mg/kg in the MES test.     

Synthesis, characterization & anticonvulsant activity of amide derivatives of 4-amino-1,2-naphthoquinone

In the present study, 4-amino-1,2-naphthoquinone analogues were synthesized and characterized by spectroscopic (FT-IR, ¹H NMR and ¹³C NMR) and elemental analysis. The synthesized compounds were evaluated for anticonvulsant activity by the maximal electroshock (MES) test and subcutaneous pentylenetetrazole (sc. PTZ) test, the most widely employed seizure models for early identification of anticonvulsant candidates, whereas their neurotoxicity was examined by rotarod test. Compounds were administered to animals at different concentrations (10, 20 & 40 mg/kg) by intraperitonial (i.p.) route and the % seizure protection was measured. The pharmacological results revealed that majority of compounds were effective in MES and sc. PTZ tests. Compounds N-(1,2-dihydro-1,2-dioxonaphthalen-4-yl)butyramide (4) and N-(1,2-dihydro-1,2-dioxonaphthalen-4-yl)-3-methylbutanamide (6) were active at the dose 40 & 20 mg/kg, respectively, while compounds N-(1,2-dihydro-1,2-dioxonaphthalen-4-yl)hexanamide (7) and 4-acetamido-N-(1,2-dihydro-1,2-dioxonaphthalen-4-yl)benzamide (10) were active at the dose 10 mg/kg and emerged as the most active compounds of the series. These compounds showed anticonvulsant effect comparable to phenytoin which was used as reference antiepileptic drug. The above-mentioned compounds have diminutive neurotoxic effects so they can move on next phase of anticonvulsant drug development.     

Synthesis and Evaluation of 3‐[(2,4‐Dioxo‐1,3,8‐triazaspiro[4.6]undec‐3‐yl)methyl]benzonitrile Derivatives as Potential Anticonvulsants

New 3‐[(2,4‐dioxo‐1,3,8‐triazaspiro[4.6]undec‐3‐yl)methyl]benzonitrile derivatives 8 – 37 were synthesized and their pharmacological activities were determined with the objective to better understand their structure–activity relationship (SAR) for anticonvulsant activity. All the compounds were evaluated for their possible anticonvulsant activity by maximal electroshock seizure (MES) and pentylenetetrazole (PTZ) test. Compounds 11 , 18 , 31 , and 32 showed significant and protective effect on seizure, when compared with the standard drug valproate. The same compounds were found to exhibit advanced anticonvulsant activity as well as lower neurotoxicity than the reference drug. From this study, it is quite apparent that there are at least three parameters for the activity of anticonvulsant drugs, that is, a lipophilic domain, a hydrophobic center, and a two‐electron donor.     

4-sulphamoylphenyl semicarbazones with anticonvulsant activity

A series of 4-sulphamoylphenyl semicarbazone derivatives were prepared starting from sulphanilamide and screened for anticonvulsant activity. The results indicated that greater protection was obtained in the maximal electroshock screen (MES) and subcutaneous strychnine (scSTY) than the subcutaneous pentylenetetrazole (scPTZ) tests. All the compounds showed low neurotoxicity when compared to the clinically used drugs. Compounds with substituted acetophenone (8-11) showed good activity in the rat oral MES screen. Seven compounds (6, 8-10, 12, 14 and 15) exhibited anticonvulsant activity greater than sodium valproate. Among the new derivatives evaluated, compound 10 emerged as the most active compound as indicated by its protection in the MES and scSTY screens and with low neurotoxicity. Seven compounds possessed sedative-hypnotic activity.     

Synthesis and biological evaluation of new N-substituted-N'-(3,5-di/1,3,5-trimethylpyrazole-4-yl)thiourea/urea derivatives.

Several thiourea and urea derivatives were prepared by the reaction of 4-aminopyrazoles with substituted isothiocyanates or isocyanates. The novel compounds were tested anticonvulsant activity using by pentylenetetrazole-induced seizure (PTZ) and maximal electroshock seizure (MES) tests. Among the tested compounds, thiourea derivatives of 4b were afforded 90 and 100% protection in PTZ and MES tests at 50mg/kg, respectively. Urea derivatives of 5a and 5b were afforded 82 and 100% protection both at 25 and 50mg/kg. Also synthesized compounds were screened for antituberculosis activity against Mycobacterium tuberculosis H37Rv at 6.25 microg/mL concentration but they were not found active at these concentration. In addition, some selected compounds were evaluated for in vitro anti-HIV activity and they were all negative.     

The effect ofN-alkyloxycarbonyl group on the anticonvulsant activities ofN-alkyloxycarbonyl-α-aminoglutarimides

In connection with the development of new anticonvulsant agents with a broad spectrum, we reported thatN-Cbz-α-aminoglutarimides, combining common structures of other anticonvulsants such as N-CO-C-N and cyclic imides in a single molecule, showed significant anticonvulsant activities in the MES (maximal electroshock seizure) and PTZ (pentylenetetrazole induced seizure) tests. In these studies, a series of (R) and (S)N-alkyloxycarbonyl-α-aminoglutarimides7a∼7e and8a∼8e, which were substituted with various alkyloxycarbonyl group instead ofCbz group, were prepared from the corresponding (R) and (S)N-Cbz-glutamic acid3 and4, and were evaluated with their anticonvulsant activities against the MES and PTZ tests, including neurotoxicity, in order to define the effect ofN-alkyloxycarbonyl group on the anticonvulsant activities ofN-alkyloxycarbonyl-α-aminoglutarimides. Among them, (S)N-4-nitrobenzyloxycarbonyl-α-amino-N-methylglutarimide8e was the most active in MES (ED₅₀=35.6 mg/kg, Pl=2.7) and PTZ tests (ED₅₀=15.6, Pl=6.1). Interestingly, (R) and (S)N-4-nitrobenzyloxycarbonyl-α-amino-N-methylglutarimide7e and8e and (R)N-phenoxycarbonyl-α-amino-N-methylglutrimide7d showed significant anticonvulsant activities in both the MES and PTZ tests and other compounds showed anticonvulsant activities in only the PTZ test. In addition, it was found that their anticonvulsant activities were dependent on their stereochemistries andN-substituted alkyloxycarbonyl groups.     

Search for New Anticonvulsant Compounds,Part 2. Structure-Activity Relationship Studies of New N-Substituted Amides of α-Piperazine-γ-Hydroxybutyric Acid as Active Anticonvulsants

In a search for new anticonvulsants, two series of compounds, viz. derivatives of N-benzylamides of α-(4-phenylpiperazine)-γ-hydroxybutyric acid ( A and derivatives of N-benzylamides of α-(4-benzylpiperazine)-γ-hydroxybutyric acid ( B ), were investigated. These amides were obtained by aminolysis of 3-(4-phenyl-, or 4-benzylpiperazine)-tetrahydrofuran-2-one with primary arylalkylamines (i.e. 2-phenylethylamine and 2,3,4-substituted derivatives of benzylamine). Preliminary pharmacological tests, a maximal electroshock (MES) and a subcutaneous metrazole (scMet), and a rotorod toxicity assay were employed. All compounds displayed anticonvulsant activity at range of doses 100–300 mg/kg in the MES screens. In order to point to some structural features correlating with the MES anticonvulsant activity crystal structure analysis followed by conformational analysis was carried out on two representative compounds of series A and B .