Experimental pharmacological research regarding some new quinazolin-4-ones derivatives

A series of new compounds with quinazolin-4-one structure, synthesized by the Pharmaceutical Chemistry Department of the Faculty of Pharmacy of the University of Medicine and Pharmacy “Carol Davila” Bucharest, was studied. Five of them were selected, conventionally named S1, S2, S3, S4, S5, and investigated in terms of their potential influence on the central nervous system (CNS). For this purpose, the antidepressant effect was determined using the forced swimming test; the anxiolytic/ anxiogenic effect was determined using the suspended plus-shaped maze (Ugo Basile); the effect on the motor activity was determined using the Ugo Basile activity cage; and the potential analgesic effect was investigated using the hot plate test (Ugo Basile). Compounds S3 and S5 lowered the motor activity and showed an anxiolytic effect, while S1 and S2 proved to have antidepressant and analgesic effects. A good correlation between antidepressant and analgesic effects was observed, consistent with the fact that analgesic drugs, by increasing norepinephrine and serotonin levels in the pain inhibiting descendent pathways, can be used as co-analgesics in therapy

Experimental pharmacological research regarding the antidepressant effect of associating doxepin and selegiline in normal mice

The severity and complexity of depression can vary widely among individuals, thus making single drug therapy ineffective in some cases. Taking this fact into account and using a mouse model, we set on investigating the possibility of obtaining a synergism of action between a classical tricyclic antidepressant that inhibits noradrenalin and serotonin reuptake (doxepin), and a modern antidepressant that inhibits type-B monoamine oxidase (selegiline). We measured the antidepressant effect using the forced swimming test and the tail suspension test. We determined motor activity using the Activity Cage test. Our results have shown that the antidepressant effect intensifies significantly in the animals treated with both antidepressants simultaneously compared to those treated only with doxepin. Furthermore, we observed that selegiline decreases the sedative effect of doxepin in the Activity Cage test

Thioureides of 2-(phenoxymethyl)benzoic acid 4-R substituted: a novel class of anti-parasitic compounds

Fifty members of a novel class of antimicrobial compounds, 2-(4-R-phenoxymethyl)benzoic acid thioureides, were synthesized and characterized with respect to their activities against three parasites of human relevance, namely the protozoa Giardia lamblia and Toxoplasma gondii, and the larval (metacestode) stage of the tapeworm Echinococcus multilocularis. To determine the selective toxicity of these compounds, the human colon cancer cell line Caco2 and primary cultures of human foreskin fibroblasts (HFF) were also investigated. The new thioureides were obtained in a three-step-reaction process and subsequently characterized by their physical constants (melting point, solubility). The chemical structures were elucidated by (1)H NMR, (13)C NMR, IR spectral methods and elemental analysis. The analyses confirmed the final and intermediate compound structures and the synthesis. The compounds were then tested on the parasites in vitro. All thioureides, except two compounds with a nitro group, were totally ineffective against Giardia lamblia. 23 compounds inhibited the proliferation of T. gondii, three of them with an IC(50) of approximately 1 microM. The structural integrity of E. multilocularis metacestodes was affected by 22 compounds. In contrast, HFF were not susceptible to any of these thioureides, while Caco2 cells were affected by 17 compounds, two of them inhibiting proliferation with an IC(50) in the micromolar range. Thioureides may thus present a promising class of anti-infective agents

Antimicrobial Features of Organic Functionalized Graphene-Oxide with Selected Amines

(1) Background: Graphene oxide is a new carbon-based material that contains functional groups (carboxyl, hydroxyl, carbonyl, epoxy) and therefore can be easily functionalized with organic compounds of interest, yielding hybrid materials with important properties and applications. (2) Methods: Graphene oxide has been obtained by a modified Hummers method and activated by thionyl chloride in order to be covalently functionalized with amines. Thus obtained hybrid materials were characterized by infrared and Raman spectroscopy, elemental analysis and scanning electron microscopy and then tested for their antimicrobial and anti-biofilm activity. (3) Results: Eight amines of interest were used to functionalize grapheme oxide and the materials thus obtained were tested against Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacterial strainsin plankonic and biofilm growth state. Both amines, as well as the functionalized materials, exhibited anti-microbial features. Three to five functionalized graphene oxide materials exhibited improved inhibitory activity against planktonic strains as compared with the respective amines. In exchange, the amines alone proved generally more efficient against biofilm-embedded cells. (4) Conclusions: Such hybrid materials may have a wide range of potential use in biomedical applications

Respiratory burst oxidase-D Expression and Biochemical Responses in Festuca arundinacea under Drought Stress

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases catalyze the production of superoxide, a type of reactive oxygen species (ROS). In plants, the NADPH oxidase homologs have been identified as respiratory burst oxidase homologs (Rboh). They are involved in ROS production in response to drought stress. Three entries of tall fescue (Festuca arundinacea Schreb.) were used for analyses in the present study: tolerant (‘Isfahan’) and sensitive (‘Quchan’) accessions to drought during the germination stage, selected from 14 wild populations in Iran, as well as ‘Barvado’ as a control. Partial sequence of the Festuca respiratory burst oxidase-D (FrbohD) gene was isolated from Barvado. We compared expression levels of the FrbohD gene as well as hydrogen peroxide (H2O2), catalase activity and some biochemical responses among the three entries. Gene expression was evaluated for leaf and shoot samples subjected to 3, 6, and 9 d without water. The transcript level of FrbohD, H2O2 content, and catalase activity increased in Quchan under drought stress. It appears that lower levels of FrbohD gene transcription and H2O2 concentration in F. arundinacea leaves contributed to drought stress tolerance in Isfahan. Total protein and total soluble carbohydrate content also increased significantly in Isfahan when it was subjected to drought stress. Isfahan exhibited drought resistance through various strategies, which could serve as selection criteria for improving drought resistance in turfgrass breeding programs

Design, Synthesis and In Vitro Characterization of Novel Antimicrobial Agents Based on 6-Chloro-9H-carbazol Derivatives and 1,3,4-Oxadiazole Scaffolds

In this paper, we aimed to exploit and combine in the same molecule the carbazole and the 1,3,4-oxadiazole pharmacophores, to obtain novel carprofen derivatives, by using two synthesis pathways. For the first route, the following steps have been followed: (i) (RS)-2-(6-chloro-9H-carbazol-2-yl)propanonic acid (carprofen) treatment with methanol, yielding methyl (RS)-2-(6-chloro-9H-carbazol-2-yl)propanoate; (ii) the resulted methylic ester was converted to (RS)-2-(6-chloro-9H-carbazol-2-yl)propane hydrazide (carprofen hydrazide) by treatment with hydrazine hydrate; (iii) reaction of the hydrazide derivative with acyl chlorides led to N-[(2RS)-2-(6-chloro-9H-carbazol-2-yl)propanoil]-N′-R-substituted-benzoylhydrazine formation, which; (iv) in reaction with phosphorus oxychloride gave the (RS)-1-(6-chloro-9H-carbazol-2-yl)-1-(1,3,4-oxadiazol-2-yl)ethane derivatives. In the second synthesis pathway, new 1,3,4-oxadiazole ring compounds were obtained starting from carprofen which was reacted with isoniazid, in the presence of phosphorus oxychloride to form (RS)-1-(6-chloro-9H-carbazol-2-yl)-1-[5-(4-pyridyl)-1,3,4-oxadiazol-2-yl]ethane. The synthesized compounds were characterized by IR, 1H-NMR and 13C-NMR, screened for their drug-like properties and evaluated for in vitro cytotoxicity and antimicrobial activity. The obtained compounds exhibited a good antimicrobial activity, some of the compounds being particularly active on E. coli, while others on C. albicans. The most significant result is represented by their exceptional anti-biofilm activity, particularly against the P. aeruginosa biofilm. The cytotoxicity assay revealed that at concentrations lower than 100 μg/mL, the tested compounds do not induce cytotoxicity and do not alter the mammalian cell cycle. The new synthesized compounds show good drug-like properties. The ADME-Tox profiles indicate a good oral absorption and average permeability through the blood brain barrier. However, further research is needed to reduce the predicted mutagenic potential and the hepatotoxicity

The use of structural alerts to avoid the toxicity of pharmaceuticals

In order to identify compounds with potential toxicity problems, particular attention is paid to structural alerts, which are high chemical reactivity molecular fragments or fragments that can be transformed via bioactivation by human enzymes into fragments with high chemical reactivity. The concept has been introduced in order to reduce the likelihood that future candidate substances as pharmaceuticals will have undesirable toxic effects. A significant proportion (∼78–86%) of drugs characterized by residual toxicity contain structural alerts; there is also evidence indicating the formation of active metabolites as a causal factor for the toxicity of 62–69% of these molecules. On the other hand, the pharmacological action of certain drugs depends on the formation of reactive metabolites. Detailed assessment of the potential for the formation of active metabolites is recommended to characterize a biologically active compound. Although many prescribed drugs frequently contain structural alerts and form reactive metabolites, the vast majority of these drugs are administered in low daily doses. Avoiding structural alerts has become almost a norm in new drug design. An in-depth review of the biochemical reactivity of these structural alerts for new drug candidates is critical from a safety point of view and is currently being monitored in the discovery of drugs. The chemical strategies applied to structural alerts in molecules to limit the toxicity are: • partial replacement or full replacement of the structural alert; • reduction of electronic density; • introduction of a structural element of metabolic interest (metabolic switching); • multiple approaches.Therefore, chemical intervention strategies to eliminate bioactivation are often interactive processes; their success depends largely on a close working relationship between drug chemists, pharmacologists and researchers in metabolic science. Keywords: Structural alerts, Active metabolites, Toxicit