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Background: Our previous studies showed that xanthone derivatives with N-(2-methoxyphenyl)piperazine fragment have an affinity to the 5-HT1A receptor and show antidepressant-like properties in rodents. In this study, we tested three xanthone derivatives, HBK-1 (R, S) and its enantiomers, in which we increased the distance between the piperazine and xanthone fragments by using a hydroxypropoxy linker. We hypothesized that this would increase the binding to the 5-HT1A receptor and consequently, pharmacological activity. Aims: We aimed to assess the in vitro and in vivo pharmacological activity of the xanthone derivatives. Methods: We evaluated the in vitro affinity for serotonin 5-HT1A and 5-HT2A receptors and serotonin transporter. We also determined the intrinsic activity at the 5-HT1A receptor. We investigated the antidepressant-like properties and safety after acute administration (dose range: 1.25–20 mg/kg) using the forced swim, tail suspension, locomotor activity, rotarod and chimney tests in mice. We also evaluated the basic pharmacokinetic parameters. Results: Our results indicated that the compounds showed a high affinity for the 5-HT1A receptor but very weak antagonistic properties in the Ca2+ mobilization assay; however, they showed significant agonistic properties in the β-arrestin recruitment assay. In both behavioural tests the studied xanthone derivatives showed antidepressant-like activity. Pre-treatment with p-chlorophenylalanine or WAY-100635 abolished their antidepressant-like activity. None of the compounds caused motor impairments at antidepressant-like doses. The racemate penetrated the blood–brain barrier and had a relatively high bioavailability after intraperitoneal administration. Conclusions: Xanthone derivatives with N-(2-methoxyphenyl)piperazine fragment and hydroxypropoxy linker show increased binding to the 5-HT1A receptor and may represent an attractive putative treatment candidate for depression.

Anticonvulsant drugs are used to treat a wide range of non-epileptic conditions, including chronic, neuropathic pain. We obtained a phenoxyalkylaminoalkanol derivative, KM-416 which had previously demonstrated a significant anticonvulsant activity and had also been shown to bind to 5-HT1A, α2-receptors and SERT and not to exhibit mutagenic properties. As KM-416 is a promising compound in our search for drug candidates, in the present study we further assessed its pharmacological profile (analgesic, local anesthetic, and antidepressant-like activities) accompanied with patch-clamp studies. Considering the importance of drug safety, its influence on the cardiovascular system was also evaluated. Moreover, KM-416 was subjected to forced degradation and pharmacokinetic studies to examine its stability and pharmacokinetic parameters. KM-416 revealed a significant antinociceptive activity in the tonic - the formalin test, neurogenic - the capsaicin test, and neuropathic pain model - streptozotocin-induced peripheral neuropathy. Moreover, it exerted a local anesthetic effect. In addition, KM-416 exhibited anti-depressant like activity. The results from the patch-clamp studies indicated that KM-416 can inhibit currents elicited by activation of NMDA receptors, while it also exhibited a voltage-dependent inhibition of Na+ currents. KM-416 did not influence ventricular depolarization and repolarization. Following oral administration, pharmacokinetics of KM-416 was characterized by a rapid absorption in the rat. The brain-to-plasma AUC ratio was 6.7, indicating that KM-416 was well distributed to brain. The forced degradation studies showed that KM-416 was very stable under stress conditions. All these features made KM-416 a promising drug candidate for further development against neuropathic pain and epilepsy.

Epilepsy and neuropathic pain are frequent neurological disorders with pathomechanism based on abnormal neuronal discharges. Secondary tissue impairment observed after traumatic brain injury is also connected with neuronal dysfunction. Those three neurological disorders are ineffectively treated with currently available pharmacotherapy options so great effort is made in searching for new effective drugs. Four N-(E)-cinnamoyl (cinnamamide) derivatives of aminoalkanols: S-(2E)-N-(1-hydroxypropan-2-yl)-3-(2-methylphenyl)prop-2-enamide (1), R,S-(2E)-3-(4-chlorophenyl)-N-(1-hydroxybutan-2-yl)prop-2-enamide (2), R,S-(2E)-3-(4-chlorophenyl)-N-(2-hydroxypropyl)prop-2-enamide (3), (2E)-3-(4-chlorophenyl)-N-(4-hydroxycyclohexyl)prop-2-enamide (4) were evaluated in vivo and in vitro for anticonvulsant, neuroprotective and/or analgesic activity. In intravenous metrazol seizure threshold test compounds 1–3 did not show pro-convulsive effect but proved anticonvulsant potential. In corneal kindled mice model the tested compounds showed beneficial anticonvulsant properties with ED50 of 36.8 mg/kg for 1, 25.7 mg/kg for 2, and 51.1 mg/kg for 3. Compound 2 tested in vitro in spontaneously bursting rat hippocampal slice model significantly reduced burst rate. Compounds 1 and 2 did not decrease lesion volume in acute model of traumatic brain injury. In formalin test of hyperalgesia in mice, compound 1 was active in the acute phase of the test, while compound 4 caused reduction of the time of licking of the affected paw by approx. 88% during the acute phase and 100% during the inflammatory phase. In rat sciatic ligation model of neuropathic pain, compound 1 significantly increased the paw withdrawal threshold starting from one hour after oral administration and the activity continued up to six hours. Reported here four N-(E)-cinnamoyl derivatives of aminoalkanols possess promising activity as anticonvulsant and/or analgesic agents.

Effective protection from the harmful effects of UV radiation may be achieved by using sunscreens containing organic or inorganic UV filters. The number of currently available UV filters is limited and some of the allowed molecules possess limitations such as systemic absorption, endocrine disruption properties, contact and photocontact allergy induction, and low photostability. In the search for new organic UV filters we designed and synthesized a series consisting of 5-benzylidene and 5-(3-phenylprop-2-en-1-ylidene)imidazolidine-2,4-dione (hydantoin) derivatives. The photoprotective activity of the tested compounds was confirmed in methanol solutions and macrogol formulations. The most promising compounds possessed similar UV protection parameter values as selected commercially available UV filters. The compound diethyl 2,2&prime, ((Z)-4-((E)-3-(4-methoxyphenyl)allylidene)-2,5-dioxoimidazolidine-1,3-diyl)diacetate (4g) was characterized as an especially efficient UVA photoprotective agent with a UVA PF of 6.83 &plusmn, 0.05 and favorable photostability. Diethyl 2,2&prime, ((Z)-4-(4-methoxybenzylidene)-2,5-dioxo- imidazolidine-1,3-diyl)diacetate (3b) was the most promising UVB-filter, with a SPFin vitro of 3.07 &plusmn, 0.04 and very good solubility and photostability. The main photodegradation products were geometric isomers of the parent compounds. These compounds were also shown to be non-cytotoxic at concentrations up to 50 &micro, M when tested on three types of human skin cells and possess no estrogenic activity, according to the results of a MCF-7 breast cancer model.

In vitro mutagenic, antimutagenic, and antioxidant potency evaluation and biotransformation of six novel 4-substituted 1-(2-methoxyphenyl)piperazine derivatives demonstrating antidepressant-like activity were investigated. Mutagenic and antimutagenic properties were assessed using the Ames test; free radical scavenging activity was evaluated with 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay and biotransformation was performed with liver microsomes. It was found that all tested compounds are not mutagenic in bacterial strains TA100 and TA1535 and exhibit antimutagenic effects in the Ames test. Noteworthy, compounds possessing propyl linker between phenoxyl and N-(2-methoxyphenyl)piperazine displayed more pronounced antimutagenic properties than derivatives with ethoxyethyl linker. Additionally, compounds 2 and 6 in vitro biotransformation showed that primarily their hydroxylated or O-dealkylated metabolites are formed. Some of the compounds exhibited intrinsic clearance values lower than those reported previously for antidepressant imipramine. To sum up, the results of the present study might represent a valuable step in designing and planning future studies with piperazine derivatives.

A series of thirty N-(phenoxy)alkyl or N-{2-[2-(phenoxy)ethoxy]ethyl}aminoalkanols has been designed, synthesized and evaluated for anticonvulsant activity in MES, 6 Hz test, and pilocarpine-induced status epilepticus. Among the title compounds, the most promising seems R-(−)-2N-{2-[2-(2,6-dimethylphenoxy)ethoxy]ethyl}aminopropan-1-ol hydrochloride (22a) with proved absolute configuration with X-ray analysis and enantiomeric purity. The compound is effective in MES test with ED50 = 12.92 mg/kg b.w. and its rotarod TD50 = 33.26 mg/kg b.w. The activity dose is also effective in a neurogenic pain model—the formalin test. Within high throughput profile assay, among eighty one targets, the strongest affinity of the compound is observed towards σ receptors and 5-HT transporter and the compound does not bind to hERG. It also does not exhibit mutagenic properties in the Vibrio harveyi test. Moreover, murine liver microsomal assay and pharmacokinetics profile (mice, iv, p.o., ip) indicate that the liver is the primary site of biotransformation of the compound, suggesting that both 22a and its metabolite(s) are active, compensating probably low bioavailability of the parent molecule.

Aim of the study was evaluation of anxiolytic, antidepressant, anticonvulsant and analgesic activity in a series of a consistent group of compounds. A series of eleven new N-(phenoxyalkyl)- or N-{2-[2-(phenoxy)ethoxy]ethyl}piperazine derivatives has been obtained. Their affinity towards 5-HT1A, 5-HT2A, 5-HT6, 5-HT7, D2 and α1 receptors has been assessed, and then functional assays were performed. The compounds were evaluated in mice, i.p. for their antidepressant-like (forced swim test), locomotor, anxiolytic-like (four-plate test) activities as well as – at higher doses – for anticonvulsant potential (MES) and neurotoxicity (rotarod). Two compounds (3, 6) were also evaluated for their analgesic activity in neuropathic pain models (streptozocin test, oxaliplatin test) and they were found active against allodynia in diabetic neuropathic pain at 30 mg/kg. Among the compounds, anxiolytic-like, anticonvulsant or analgesic activity was observed but antidepressant-like activity was not. One of the two most interesting compounds is 1-{2-[2-(2,4,6-trimethylphenoxy)ethoxy]ethyl}-4-(2-methoxyphenyl)piperazine dihydrochloride (9), exhibiting anxiolytic and anticonvulsant activity in mice, i.p. 30 min after administration (at 2.5 mg/kg and ED50 = 26.33 mg/kg, respectively), which can be justified by the receptor profile: 5-HT1A Ki = 5 nM (antagonist), 5-HT7 Ki = 70 nM, α1 Ki = 15 nM, D2 Ki = 189 nM (antagonist). Another interesting compound is 1-[3-(2,4,6-trimethylphenoxy)propyl]-4-(4-methoxyphenyl)piperazine dihydrochloride (3), exhibiting anxiolytic, anticonvulsant and antiallodynic activity in mice, i.p., 30 min after administration (at 10 mg/kg, ED50 = 23.50 mg/kg, at 30 mg/kg, respectively), which can be related with 5-HT1A weak antagonism (Ki = 146 nM), or other possible mechanism of action, not evaluated within presented study. Additionally, for the most active compound in the four-plate test (7), molecular modeling was performed (docking to receptors 5-HT1A, 5-HT2A, 5-HT7, D2 and α1A).

Summary Reactive oxygen species (ROS) are critically involved in the action of anticancer agents. In this study, we investigated the role of ROS in the anticancer mechanism of new aminoalkanol derivatives of xanthone. Most xanthones used in the study displayed significant pro-oxidant effects similar to those of gambogic acid, one of the most active anticancer xanthones. The pro-oxidant activity of our xanthones was shown both directly (by determination of ROS induction, effects on the levels of intracellular antioxidants, and expression of antioxidant enzymes) and indirectly by demonstrating that the overexpression of manganese superoxide dismutase decreases ROS-mediated cell senescence. We also observed that mitochondrial dysfunction and cellular apoptosis enhancement correlated with xanthone-induced oxidative stress. Finally, we showed that the use of the antioxidant N-acetyl-L-cysteine partly reversed these effects of aminoalkanol xanthones. Our results demonstrated that novel aminoalkanol xanthones mediated their anticancer activity primarily through ROS elevation and enhanced oxidative stress, which led to mitochondrial cell death stimulation; this mechanism was similar to the activity of gambogic acid.

A series of new xanthone derivatives have been synthesized and evaluated for their anticonvulsant properties in the maximal electroshock (MES), subcutaneous metrazole (ScMet) tests as well as for neurotoxicity in the rotarod (TOX) in mice, i.p. and rats, p.o. Compound 9: R,S-2-{2-[(1-hydroxybutan-2-yl]amino)ethoxy}-9H-xanthen-9-one and compound 12: R,S-2-{3-[(1-hydroxybutan-2-yl)amino]propoxy}-9H-xanthen-9-one exerted activity in rats, p.o. 2 and 4 h after administration, respectively. Therefore, metabolic stability of the compounds was evaluated with use of rats microsomes, resulting in half-life t1/2 136 and 108 min, respectively, indicating that either the metabolites are very active, or the parent compounds exert other ADME properties other than metabolism which influence the late onset of activity. This article is protected by copyright. All rights reserved.

A series of twenty two (E)-N-cinnamoyl aminoalkanols derivatives monosubstituted in phenyl ring with 4-Cl, 4-CH

A series of (E)-α-methylcinnamyl derivatives of selected aminoalkanols was synthetized and evaluated for activity in central nervous system. All compounds were tested as anticonvulsants and one additionally in antidepressant- and anxiolytic-like assays. The compounds possessed pharmacophoric elements regarded as beneficial for anticonvulsant activity: hydrophobic unit and two hydrogen bonds donor/acceptor features. The compounds were verified in mice after intraperitoneal (i.p.) administration in maximal electroshock (MES) and subcutaneous pentetrazole (scPTZ) induced seizures as well as neurotoxicity assessments. Eight of the tested substances showed protection in MES test at the dose of 100 mg/kg. The derivative of 2-aminopropan-1-ol was also tested in 6-Hz test in mice i.p. and showed anticonvulsant activity but at the same time the neurotoxicity was noted. The derivative of 2-amino-1-phenylethanol which possessed additional hydrophobic unit in aminoalkanol moiety was tested in other in vivo assays to evaluate antidepressant- and anxiolytic-like activity. The compound proved beneficial properties especially as anxiolytic agent remaining active in four-plate test in mice at the dose of 2.5 mg/kg (i.p.). In vitro biotransformation studies of 2-amino-1-phenylethanol derivative carried out in mouse liver microsomal assay indicated two main metabolites as a result of aliphatic and aromatic hydroxylation or aliphatic carbonylation. To identify possible mechanism of action, we evaluated serotonin receptors (5-HT1A, 5-HT6 and 5-HT7) binding affinities of the compounds but none of them proved to bind to any of tested receptors.

Epilepsy, one of the most frequent neurological disorders, is still insufficiently treated in about 30% of patients. As a consequence, identification of novel anticonvulsant agents is an important issue in medicinal chemistry. In the present article we report synthesis, physicochemical, and pharmacological evaluation of N-trans-cinnamoyl derivatives of R and S-2-aminopropan-1-ol, as well as R and S-2-aminobutan-1-ol. The structures were confirmed by spectroscopy and for derivatives of 2-aminopropan-1-ols the configuration was evaluated by means of crystallography. The investigated compounds were tested in rodent models of seizures: maximal electroshock (MES) and subcutaneous pentetrazol test (scPTZ), and also in a rodent model of epileptogenesis: pilocarpine-induced status prevention. Additionally, derivatives of 2-aminopropan-1-ols were tested in benzodiazepine-resistant electrographic status epilepticus rat model as well as in vitro for inhibition of isoenzymes of cytochrome P450. All of the tested compounds showed promising anticonvulsant activity in MES. For R(-)-(2E)-N-(1-hydroxypropan-2-yl)-3-phenylprop-2-enamide pharmacological parameters were found as follows: ED50 = 76.7 (68.2-81.3) mg/kg (MES, mice i.p., time = 0.5 h), ED50 = 127.2 (102.1-157.9) mg/kg (scPTZ, mice i.p., time = 0.25 h), TD50 = 208.3 (151.4-230.6) mg/kg (rotarod, mice i.p., time = 0.25 h). Evaluation in pilocarpine status prevention proved that all of the reported compounds reduced spontaneous seizure activity and act as antiepileptogenic agents. Both enantiomers of 2-aminopropan-1-ols did not influence cytochrome P450 isoenzymes activity in vitro and are likely not to interact with CYP substrates in vivo. Chirality 28:482-488, 2016. © 2016 Wiley Periodicals, Inc.

Since serotonin (5-HT) is strongly involved in the etiology and pathophysiology of depression, the development of new antidepressants is still based on the serotonergic system. The complexity of serotonergic system provides an opportunity for the development of compounds with multiple and complementary mechanism of action. This study describes serotonin receptor profile, functional characterization, and pharmacological in vivo evaluation of new aroxyalkyl derivatives of 2-methoxyphenylpiperazine. The obtained results allowed for the identification of compound 3, (1-[3-(2,6-dimethylphenoxy)propyl]-4-(2-methoxyphenyl)piperazine hydrochloride), a partial 5-HT1A receptor agonist, and 5-HT2A receptor antagonist, with high affinity toward 5-HT7 receptors, showing antidepressant- and anxiolytic-like properties. Moreover, 5-HT1A receptor activation is crucial for the antidepressant-like activity of compound 3. The rest of the compounds (except compounds 1 and 9) showed antidepressant but not anxiolytic-like properties, which did not result from 5-HT1A receptors activation. Furthermore, the compounds are 5-HT1A and weak 5-HT3 receptors antagonists, and some of them 5-HT2A antagonists. Moreover, none of the studied compounds impaired motor coordination at antidepressant-like doses. Since the studied compounds exhibited activity in behavioral assays and interacted with various receptors, the results of our experiments are very promising and require further studies.

Xanthone derivatives possess many biological properties, including neuroprotective, antioxidant or antidepressant-like. In this study we aimed to investigate antidepressant- and anxiolytic-like properties of a new xanthone derivative - 6-methoxy-4-[4-(2-methoxyphenyl)piperazin-1-yl]-9H-xanthen-9-one (HBK-7), as well as its possible mechanism of action, and the influence on cognitive and motor function. HBK-7 in our earlier studies showed high affinity for serotonergic 5-HT1A receptor. We determined the affinity of HBK-7 for CNS receptors and transporters using radioligand assays and examined its intrinsic activity towards 5-HT1A receptor. We evaluated antidepressant- and anxiolytic-like activity of HBK-7 in the mouse forced swim test, and four-plate test, respectively. We examined the influence on locomotor activity in mice to determine if the effect observed in the forced swim test was specific. We used step-through passive avoidance and rotarod tests to evaluate the influence of HBK-7 on cognitive and motor function, respectively. HBK-7 showed moderate affinity for dopaminergic D2 receptor and very low for serotonergic 5-HT2A, adrenergic α2 receptors, as well as serotonin transporter. Functional studies revealed that HBK-7 was a 5-HT1A receptor antagonist. HBK-7 (10mg/kg) decreased immobility time in the forced swim test. Combined treatment with sub-effective doses of HBK-7 and fluoxetine reduced immobility of mice in the forced swim test. Pretreatment with p-chlorophenylalanine and WAY-100,635 antagonized the antidepressant-like effect of HBK-7. Neither of the treatments influenced locomotor activity of mice. HBK-7 at antidepressant-like dose did not impair memory or motor coordination in mice. We demonstrated that HBK-7 was a 5-HT1A receptor antagonist with potent, comparable to mianserin, antidepressant-like activity. HBK-7 mediated its effect through serotonergic system and its antidepressant-like action required the activation of 5-HT1A receptors. At active dose it did not influence cognitive and motor function. Since 5-HT1A receptor antagonists may accelerate the occurrence of antidepressant effect, our findings highlight their potential as future antidepressants.

A group of trans - and cis -2-(2,6-dimethylphenoxy)- N -(2-hydroxycyclohexyl)acetamides ( 1 – 7 ) and -ethylamines ( 8 – 9 ) have been synthesized and investigated for their anticonvulsant activity. One of them, racemic trans -2-(2,6-dimethylphenoxy)- N -(2-hydroxycyclohexyl)acetamide proved to be the most effective in MES (mice, ip), exhibiting ED 50 = 42.97 mg/kg b.w. and TD 50 = 105.67 mg/kg b.w. It also proved protection in focal seizures (electric kindling, rats, ip) and it raises seizure threshold. The mechanism of action is inhibition of voltage-gated sodium currents and enhancement of GABA effect. Safety pharmacology assay on threshold tonic extension revealed no lowering of the seizure threshold.

A series of new (phenoxyethyl)aminoalkanol derivatives were synthesized and evaluated for their anticonvulsant activity. The most promising compound seemed to be (R,S)-1N-[(2,6-dimethyl)phenoxyethyl]amino-2-butanol, which displayed anti-MES activity (in mice, i.p.) with protective index (TD50/ED50) of 5.712, corresponding to that of phenytoin (6.6), carbamazepine (4.9) and valproate (1.7). The lipophilicity of compounds 1–17 exhibiting anticonvulsant activity was investigated. Their lipophilicities (RM0) were determined using reversed-phase thin-layer chromatography (RP-TLC) with a mixture of acetone and water as mobile phases. The partition coefficients of 1–17 (logP) were also calculated using two computer programs (Pallas and ALOGPS) and compared with RM0. The relationship between anticonvulsant activity and lipophilicity of the tested substances was estimated. Copyright © 2010 John Wiley & Sons, Ltd.

The lipophilicity of a number of N-acyl derivatives of trans- or cis-: racemic, (1R,2R)- or (1S,2S)-aminocyclohexanol (1–13) exhibiting anticonvulsant activity was investigated. Their lipophilicity (Rm0) was determined using reversed-phase thin-layer chromatography (RP-TLC) with mixtures of methanol and water as mobile phases. The partition coefficients of compounds 1–13 (log P) were also calculated using two computer programs (Pallas and Chem DU) and compared with Rm0. Copyright © 2009 John Wiley & Sons, Ltd.

Adequate control of seizures remains an unmet need in epilepsy. In order to identify new anticonvulsant agents, a series of N-trans-cinnamoyl derivatives of selected aminoalkanols was synthetized. The compounds were obtained in the reaction of N-acylation carried out in a two-phase system. The substances were tested in animal models of seizures induced either electrically (maximal electroshock--MES; 6-Hz test) or chemically, by subcutaneous injection of pentetrazol (scPTZ). Neurotoxicity was determined by the rotarod test. Lipophilicity of the active compounds, expressed as RM0, was determined by reversed-phase thin layer chromatography and it ranged from 1.390 to 2.219. From among the tested series of compounds, R,S-(E)-N-(1-hydroxypropan-2-yl)-3-phenylprop-2-enamide (1) and R,S-(E)-N-(2-hydroxypropyl)-3-phenylprop-2-enamide (3) exhibited the best anticonvulsant activity. Compound 1, when administered to mice by intraperitoneal (i.p.) injection, showed the ED50 values of 86.6, 60.9, and 109.6 mg/kg in the MES, 6-Hz, and scPTZ tests, respectively. For compound 3, the ED50 values were found to be 47.1 mg/kg in MES and 77.1 mg/kg in scPTZ (mice, i.p.). The distances measured in crystals of compound 1 were: 7.99 A--from the phenyl ring to the hydroxyl group in the amide moiety, 5.729 A--from the phenyl ring to the amide group, and 3.112 A--from the amide group to the hydroxyl group in the amide moiety. The reported compounds did not exhibit mutagenic potential when assayed in the Ames test. Compounds 1 and 3 did not affect viability and morphology of human hepatocellular carcinoma cells (HepG2).

Xanthone derivatives have been shown to posses many biological properties. Some of them act within the central nervous system and show neuroprotective or antidepressant like properties. Taking this into account we investigated antidepressant like activity in mice and the possible mechanism of action of 6-methoxy-2-[4-(2-methoxyphenyl)piperazin-1-yl]-9H-xanthen-9-one (HBK-11) - a new xanthone derivative. We demonstrated that HBK-11 produced antidepressant like effects in the forced swim test and tail suspension test, comparable to that of venlafaxine. The combined treatment with sub effective doses of HBK-11 and fluoxetine (but not reboxetine or bupropion) significantly reduced the immobility in the forced swim test. Moreover, the antidepressant like activity of HBK-11 in the aforementioned test was blocked by p-chlorophertylalanine, and significantly reduced by serotonergic $5-HT_{1A}$ receptor antagunist - WAY-1006335 and $5-HT_{2A/C}$ receptor antagonist - ritanserin. As none of the above treatments influenced the spontaneous locomotor activity, if can be concluded that HBK-11 mediates its activity through a serotonergic system, and its antidepressant like effect involves $5-HT_{1A}$ and $5-HT_{2A/C}$ receptor activation. Furthermore, at antidepressant like doses HBK-11 did not cause the mice to display locomotor deficits in rotarod or chimney rests. Considering the pharmacokinetic profile, HBK-11 demonstrated rapid absorption after i.p. administration, high clearance value, short terminal half-life, very high volume of distribution and incomplete bioavailabilily. The compound studied had good penetration into the brain tissue of mice. Since studied xanthone derivative seems to present interesting, untypical mechanism of antidepressant-like action i.e. $5-HT_{2A/C}$ receptor activation, it may have a potential in the treatment of depressive disorders, and surely requires further studies.

A series of new N-(2,5-dimethylphenoxy)- and N-(2,3,5-trimethylphenoxy)alkylaminoalkanols [I-XVII] was synthesized and evaluated for anticonvulsant activity. Pharmacological tests included maximal electroshock (MES) and subcutaneous pentetrazole seizure threshold (scMet) assays as well as neurotoxicity (TOX) evaluation in mice after intraperitoneal (i.p.) administration and/or in rats after oral (p.o.) administration. The most active compound was R-2N-[(2,3,5-trimethylphenoxy)ethyl]aminobutan-1-ol, which exhibited 100% activity in MES at the dose of 30 mg/kg body weight (mice, i.p.) and 75% activity in MES at 30 mg/kg b.w. (rats, p.o.) without neurotoxicity at the active doses.

The aim of this study was to further characterize pharmacological properties of two phenylpiperazine derivatives: 1-{2-[2-(2,6-dimethlphenoxy)ethoxy]ethyl}-4-(2-methoxyphenyl)piperazynine hydrochloride (HBK-14) and 2-[2-(2-chloro-6-methylphenoxy)ethoxy]ethyl-4-(2- methoxyphenyl)piperazynine dihydrochloride (HBK-15) in radioligand binding and functional in vitro assays as well as in vivo models. Antidepressant-like properties were investigated in the forced swim test (FST) in mice and rats. Anxiolytic-like activity was evaluated in the four-plate test in mice and elevated plus maze test (EPM) in rats. Imipramine and escitalopram were used as reference drugs in the FST, and diazepam was used as a standard anxiolytic drug in animal models of anxiety. Our results indicate that HBK-14 and HBK-15 possess high or moderate affinity for serotonergic 5-HT2, adrenergic α1, and dopaminergic D2 receptors as well as being full 5-HT1A and 5-HT7 receptor antagonists. We also present their potent antidepressant-like activity (HBK-14—FST mice: 2.5 and 5 mg/kg; FST rats: 5 mg/kg) and (HBK-15—FST mice: 1.25, 2.5 and 5 mg/kg; FST rats: 1.25 and 2.5 mg/kg). We show that HBK-14 (four-plate test: 2.5 and 5 mg/kg; EPM: 2.5 mg/kg) and HBK-15 (four-plate test: 2.5 and 5 mg/kg; EPM: 5 mg/kg) possess anxiolytic-like properties. Among the two, HBK-15 has stronger antidepressant-like properties, and HBK-14 displays greater anxiolytic-like activity. Lastly, we demonstrate the involvement of serotonergic system, particularly 5-HT1A receptor, in the antidepressant- and anxiolytic-like actions of investigated compounds.

A series of new derivatives of N-(2-methoxyphenyl)piperazine have been synthesized for their affinity toward serotonergic receptors and for their potential antidepressant-like activity. They have been evaluated toward receptors 5-HT1A , 5-HT6 , and 5-HT7 , as well as in vivo in the tail suspension, locomotor activity, and motor co-ordination tests. All the tested compounds proved very good affinities toward 5-HT1A and 5-HT7 receptors. The most promising compound was 1-[(2-chloro-6-methylphenoxy)ethoxyethyl]-4-(2-methoxyphenyl)piperazine hydrochloride, exhibiting affinity toward receptors Ki

A series of 6 derivatives of xanthone were synthesized and evaluated for cardiovascular activity. The following pharmacological experiments were conducted: the binding affinity for adrenoceptors, the influence on the normal electrocardiogram, the effect on the arterial blood pressure, the effect on blood pressor response and prophylactic antiarrhythmic activity in adrenaline induced model of arrhythmia (rats, iv). Two compounds revealed nanomolar affinity for α1-adrenoceptor which was correlated with the strongest cardiovascular (antiarrhythmic and hypotensive) activity in animals' models. They were enantiomers of previously described (R,S)-4-(2-hydroxy-3-(4-(2-methoxyphenyl)piperazin-1-yl)propoxy)-9H-xanthen-9-one hydrochloride and revealed similar antiarrhythmic potential in adrenaline induced model of arrhythmia in rats after intravenous injection (ED50=0.53 mg/kg and 0.81 mg/kg, respectively). These values were lower than values obtained for reference drug urapidil. These compounds were more active in this experiment than urapidil (ED50=1.26 mg/kg). The compound 5 administered iv at doses of 0.62-2.5 mg/kg at the peak of arrhythmia prevented and/or reduced the number of premature ventricular beats in a statistically significant manner. The ED50 value was 1.20 mg/kg. The S-enantiomer (6) given at the same doses did not show therapeutic antiarrhythmic activity in this model. These compounds significantly decreased the systolic and diastolic blood pressure throughout the whole observation period in anesthetized, normotensive rats. The studied enantiomers showed higher toxicity than urapidil, but imperceptibly higher that another cardiovascular drugs, that is, carvedilol or propranolol. They were also evaluated for mutagenic potential in the Ames (Salmonella) test. It was found that at the concentrations tested the compounds were non mutagenic when compared to solvent control. Results were quite promising and suggested that in the group of xanthone derivatives new potential antiarrhythmics and hypotensives might be found.

Twenty four new N-[(dimethylphenoxy)alkyl]aminoalkanols have been synthesized and evaluated for anticonvulsant activity in a series of in vivo tests: the maximum electroshock (MES), 6 Hz, and subcutaneous metrazole (ScMet). The compounds were also evaluated for possible neurotoxicity in the rotarod test. The majority of the achieved compounds exhibit quantified anticonvulsant activity. The most active compound 4: R-(−)-2N-[(2,6-dimethylphenoxy)ethyl]aminopropan-1-ol is active in MES with ED50 = 5.34 (male mice, ip), 22.28 (female mice, ip), 51.19 (male mice, po), 7.43 (rats, ip), and 28.60 (rats, po). Thermal analysis proved that its hydrochloride (4a) can exist in polymorphic forms. The compound binds to σ, 5-HT1A, and α2 receptors as well as 5-HT transporter and it does not exhibit mutagenic properties.

A series of aminoalkanolic derivatives of xanthone with high affinity for β1-adrenoceptors was evaluated for antiarrhythmic activity in the model of ischemia-reperfusion in isolated hearts, as well as in barium chloride- and adrenaline-induced model of arrhythmia. In order to better understand biological activity of studied compounds, the influence on β2-adrenoceptors in guinea-pig trachea and vasorelaxant properties in rat aorta were evaluated. Furthermore, due to assessed antioxidant activity, some biochemical studies were also performed. All tested compounds showed prominent antiarrhythmic activity in the model of ventricular arrhythmias associated with coronary artery occlusion and reperfusion. In this experiment the most active was compound MH-97. Whereas, compound MH-82 was the most active in barium- and adrenaline-induced arrhythmia after i.v. or p.o. administration, respectively. These two compounds have higher affinity to β1-adrenoceptors than compound MH-87, thus it suggests that blocking properties of β1-adrenoceptors are involved in the observed antiarrhythmic effects. All studied compounds have revealed antagonistic potency for β2-adrenoceptors in tracheal smooth muscle, however weaker than that of propranolol. None of tested compounds demonstrated antioxidant effect. They also had weak calcium entry blocking activity. The results of this study suggest that new compounds with antiarrhythmic activity might be found in the group of xanthone derivatives.

Objectives: Xanthones are flavonoids with numerous activities, including antioxidant, antidepressant., or anxiolytic-like. Therefore, the aim of our study was to determine antidepressant- and anxiolytic-like properties of four xanthone derivatives (3-chloro-5-[(4-methylpiperazin-1-yl)methyl]-9H-xanthen-9-one dihydrochloride [HBK-5], 6-methoxy-2-[(4-methylpiperazin-1-yl) methyl]-9H-xanthen-9-one dihydrochloride, 2-[(4-benzylpiperazin-1-yl) methyl]-6-methoxy-9H-xanthen-9-one dihydrochloride, 2-{[4-(2-methoxyphenyl) piperazin-1-yl] methyl}-9H-xanthen-9-one hydrochloride), as well as the influence on cognitive and motor function of active compounds, using animal models. Materials and Methods: To determine the antidepressant-like activity, we used forced swim test (FST) and tail suspension test (TST) in mice. We evaluated anxiolytic-like properties in the four-plate test in mice. We studied the influence on cognitive and motor function in passive avoidance step-through and chimney tests, respectively. Results: The antidepressant-like activity (in both FST and TST) showed only HBK-5. Moreover, the compound was also active in the four-plate test, which suggests that it possessed anxiolytic-like properties. HBK-5 did not cause any cognitive and motor deficits in mice at antidepressant- and anxiolytic-like doses. Conclusions: HBK-5 may have potential in the treatment of depression or anxiety disorders, but this issue needs further studies.

A series of 17 new aminoalkanol derivatives of 6-methoxy- or 7-chloro-2-methylxanthone as well as 6-methoxy-4-methylxanthone was synthesized and evaluated for anticonvulsant activity. All compounds were verified in mice after intraperitoneal (ip) administration in maximal electroshock (MES) and subcutaneous pentetrazole (scMet) induced seizures as well as neurotoxicity assessment. Eleven of the tested substances showed protection against electrically evoked seizures in the majority of the tested mice at the dose of 100 mg/kg. Additionally, one was effective at the dose of 30 mg/kg. Five substances were active at the dose of 300 mg/kg or at the dose of 100 mg/kg in the minority of the tested mice. The most promising compound revealed ED(50) value of 47.57 mg/kg in MES (mice, ip, 1h after administration) and at the same time its TD(50) was evaluated as above 400 mg/kg. Those values gave PI (calculated as TD(50)/ED(50)) of more than 8.41. Three other synthesized xanthone derivatives also proved to act as anticonvulsants and showed ED(50) values in MES test (mice, ip) ranged 80-110 mg/kg. Results were quite encouraging and suggested that in the group of xanthone derivatives new potential anticonvulsants might be found.

A series of 1,4-piperazine derivatives was synthesized and evaluated for anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole seizure threshold (ScMet) assays and for neurotoxicity (TOX). The compounds were only moderately effective. The anticonvulsant activity was accompanied by neurotoxicity. 1-[(4-Chlor-3-methylphenoxy)-acetyl]-4-(2-methoxyphenyl)-piperazine was also evaluated in six hertz seizure test (6-Hz) and showed good activity. At the dose of 100 mg/kg b. w. the compound produced 100% protection after 0.5 h without neurotoxic effect.

In the present study, several pharmacological tests in animals were carried out to assess potential anticonvulsant, local anesthetic and hemodynamic activity of novel 2- and 4-substituted aminobutanol chiral derivatives of xanthone (hydrochlorides of: (R,S)-2-[(7-chloro)-2-xanthonemethyl)]-N-methylaminobutan-1-ol (MH-2(R,S)), (R,S)-2-(4-xanthonemethyl)-aminobutan-1-ol (MH-20(R,S)) and (R,S)-2-[(6-methoxy)-2-xanthonemethyl]-aminobutan-1-ol (MH-26(R,S)) and their pure enantiomers R and S). The obtained results provided evidence that the most interesting anticonvulsant (in maximal electroshock-test) activity was shown by compound MH-2(R), which in dose 100 mg/kg p.o., protected the mice against tonic cramp of extensors similarly as phenytoin. Moreover, this compound, in concentrations from 0.25 to 1%, also possessed high local anesthetic activity (in infiltration anesthesia), comparable to the reference compound, mepivacaine. All examined compounds suppressed the spontaneous locomotor activity in mice, especially compound MH-2(R,S) and MH-20(R,S), and their enantiomers. The impairment of motor coordination (in chimney test) for applied doses was not observed. Furthermore, compound MH-20(S) at dose corresponding to 1/10 LD50 displayed an interesting hemodynamic activity and significantly decreased systolic and diastolic blood pressure in rats. All examined compounds showed chronotropic negative effect in anesthetized rats ECG record. The most reducing heart frequency was observed for enantiomers S of aminobutanol derivatives of xanthone, especially MH-2(S). The LD50 values of the investigated compounds were comparable with LD50 value of the reference compound in local anesthesia tests--mepivacaine. These studies demonstrated different strength of enantiomers and racemic mixture in carried out tests, where the R enantiomers presented rather central and local anesthetic properties, whereas S enatiomers influenced the hemodynamic activity.

A series of xanthone derivatives were synthesized and examined for electrocardiographic, antiarrhythmic, hypotensive and anticonvulsant activities as well as for alpha(1)- and beta(1)-adrenergic binding affinities. Among the investigated compounds, some of them exhibited significant antiarrhythmic and/or hypotensive activity. The data obtained via receptor binding assay are in agreement with pharmacological results and could explain antiarrhythmic and/or hypotensive activity of the newly synthesized structures.

Some of appropriate aminoisopropanoloxy derivatives of 4-xanthone were tested for their effect on circulatory system (protection against adrenaline-, barium-, and calcium chloride-induced arrhythmias, as well as hypotensive activity and acute toxicity). The most prominent hypotensive activity was demonstrated by (+/-)-1-[4-(hydroxyethyl)-1-(piperazinyl)]-3-(4-xanthonoxy)-2-propanol dihydrochloride (II), which diminished arterial blood pressure by about 40% during one hour observation. The investigated compounds did not prevent adrenaline- and barium-induced arrhythmias. In calcium-induced model of arrhythmia compound II slightly intensified blocks (about 7%), but delayed extrasystoles (37%), efficiently prevented bigeminy (70%, p0.01) and diminished (53%, p0.05) mortality of animals. All investigated compounds decreased heart rate by 10 - 18%, prolonged P-Q section, QRS complex and Q-T interval. The most potent and significant negative chronotropic effect and markedly prolonged duration of P-Q section was demonstrated by compound II. The influence of investigated compounds on ECG components suggests that activity of compound IV is similar to class 1a anti-arrhythmic compounds according to Voughan-Williams classification of antiarrhythmic drugs, because of prolongation of P-Q and Q-T intervals and extension of QRS complex. Compounds II and IV were also evaluated for anticonvulsant activity in the maximal electroshock seizures (MES) and subcutaneous pentylenetetrazole seizure threshold (ScMet) assays and for neurotoxicity (TOX). The anti-MES activity in mice was found for IV, which in a dose of 100 mg/kg within 0.5 h after ip administration showed 75% anticonvulsant protection with 50% neurotoxicity.

A series of appropriate alkanolamine and amide derivatives of xanthone were prepared and evaluated for anticonvulsant activity using maximal electroshock (MES) and subcutaneous pentylenetetrazole (scMet) induced seizures, and for neurotoxicity (TOX) using the rotorod test on mice and rats. The most promising compounds seem to be the appropriate aminoalkanolic derivatives of 6-chloroxanthone, among which the R-(-) and S-(+)-2amino-1-propanol derivatives of 6-chloro-2-methylxanthone (2(a) and 2(b)) displayed anti-MES activity (in mice) with a protective index (TD(50)/ED(50)) of 6.23

A variety of appropriate [4-(benzyloxy) benzoyl]- and [4-(benzyloxy) benzyl] aminoalkanol derivatives [I-XVII] was synthesized and evaluated for anticonvulsant activity using the maximal electroshock (MES) and subcutaneous pentylenetetrazole (ScMet) tests in mice and rats. Neurotoxicity (TOX) was determined by the rotorod test. The most active compounds in the MES test in mice were the appropriate 4-(benzyloxy) benzyl derivatives of (R,S)- and S-(+)-2-amino-1-butanol [XI, XIII], 3-[4-(benzyloxy) benzyl] amino-3-methyl-1-butanol [XV], and S-(+)-2-[4-(benzyloxy) benzyl] amino-3-methyl-1-butanol [XVI]--all exhibiting 100% anti-MES protection (at 30 mg/kg, mice, i.p.) and non-toxic in the active doses. 4-[4-(Benzyloxy) benzyl] amino-1-butanol [X] exhibited activity in both MES and ScMet (100 mg/kg, mice, i.p., 100% anticonvulsant protection, 0.5 h and 4 h after administration, respectively).

A series of aroxyacetamides and aroxyethylamines were prepared and evaluated for anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole seizure threshold (ScMet) assays and for neurotoxicity (TOX). Most of them exhibited anticonvulsant activity in the MES screen (mice, i.p.) in the doses up to 300 mg/kg b.w. The most active compound was XVI, which given in the dose 100 mg/kg b.w. produced 100% anticonvulsant protection after 0.5 h without neurotoxicity. The most promising compound in the VIa phase (rats, p.o.) was VIII, which produced higher anticonvulsant protection (to 75% at 0.5 h).

A series of appropriate aminoalkanolic derivatives 2- or 4-methylxanthone was synthesized and evaluated for anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole seizure threshold (scPtz) assays, and for neurotoxicity (TOX). The most interesting result was the anticonvulsant activity of (R,S)-2N-(6-chloro-2-xanthonemethyl-2N-methylamino-1-propanol hydrochloride (II, which displayed anti-MES and anti-scPtz activity. Some of the obtained compounds (I - IV and V - VII) were also tested for their effect on the circulatory system (the effect on normal electrocardiogram, protection against adrenaline-, barium-, calcium- and/or strophanthine-induced arrhythmias, the effect on the arterial blood pressure and respiratory movements) and acute toxicity.

A series of novel xanthone derivatives were synthesized as potential anti-inflammatory compounds. The compounds were examined for anti-inflammatory and analgesic properties. Aspirin and ketoprofen were used as reference compounds.Acute inflammation was induced by subplantar injection of 0.1 ml of 1% carrageenan solution to the right rat paw, 1 hour after oral administration of the investigated compound. The development of paw edema was measured plethysmographically. Pain threshold in the hind paw of rat affected by inflammation was measured using an analgesimeter 4 hours after oral administration of the compounds. Mean pain thresholds were calculated for treated and control groups and the percent change from control was determined. Thus we observed irritation of gastric mucosa after use of compounds, which showed significant anti-inflammatory activity. The mucosa of the glandular part of the stomach was inspected using a binocular microscope.The preliminary investigation of the anti-inflammatory activity of the novel xanthone derivatives showed uneven anti-inflammatory and analgesic activity. The highest anti-inflammatory and analgesic activity was provided by compound MH-44. The compounds MH-41, MH-43 and MH-48 potentiated the carrageenan edema and lowered the threshold pain in comparison with control. Side effects of the active compound were examined on gastric mucosa and stomach and none of the active compounds showed significant side effects compared with nonsteroidal anti-inflammatory drugs.None of the active compounds showed significant side effects compared with nonsteroidal anti-inflammatory drugs.

A series of alkanolamides have been tested for anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole seizure treshold (ScMet) assays and for neurotoxicity (TOX) in rodents. Most interesting were the anticonvulsant results of 2N-methylaminoethanol derivative II, which displayed anti-MES activity (mice) with a protective index (TD50/ED50) of 2.536 higher than that for valproate.

Synthesis and physicochemical properties of alkanolamine derivatives of xanthone are described. Alkanolamines were synthesized by of the reaction of an appropriate aminoalcohol with corresponding 2-bromomethylxanthones. The obtained compounds 1-13 were evaluated for anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole seizure threshold (scMet) assays and for neurotoxicity (TOX). Several alkanolamines were found to be active in both the anticonvulsant tests. Most interesting were the 2-amino-1-propanol-, 1-amino-2-propanol- or 1-amino-2-butanol derivatives of 6-methoxy- or 6-chloroxanthone, which displayed anti MES activity with a protective index (TD50/ED50) in the range 2.21-5.84 corresponding with that for phenytoin, carbamazepine and valproate.

A series of alkanolamides and alkanoamines derivatives of xanthone were prepared and evaluated for antiepileptic activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazol seizure threshold (ScMet) assays and for neurotoxicity (TOX). Several analogues from the appropriate alkanolamines were found to be active in both the anticonvulsant tests. Most interesting were the anticonvulsant results of the appropriate 2-amino- or 2-N-methylamino-1-butanol derivatives of 7-chloroxanthone 8-11, which displayed anti-MES activity with a protective index (TD50/ED50) in the range 2.84-3.62 for 8-11 corresponding with that for phenytoin, carbamazepine and valproate.