66 research outputs found
DEZVOLTAREA DURABILA, CARACTERISTICA DE RESPONSABILITATE A MANAGAMENTULUI COMUNITAR
The economic development of the community must not be viewed as an ordinary quantitative increase, measured in GDP parts. It must be viewed as a whole, considering all the factors that characterise this community. It will be understood as an effect of a performing management, which manifests maximal sensitivity and ability regarding the resources coordination in order to completely satisfy the interest of its members.sustainable development, European management, geography of organizations
Synthesis and X-ray structure of a new pyrrolo[1,2-b]-pyridazine derivative
The synthesis, characterization and X-ray crystal structure of 2-(4-chloro-phenyl)-7-methylpyrrolo[1,2-b]pyridazine are reported. The compound crystallizes in the space group P21/c (No.14) with a =3.8568(1), b = 11.0690(3), c = 26.4243(7) Å, β = 92.777(1)° and Z = 4. Accurate molecular parameters for the novel heterocyclic system were obtained from intensity data collected at 113K. The molecule assumes a planar conformation in the crystal and the packing is based on π-π stacking with interplanar spacing 3.400 Å, typical of aromatic molecules with potential for displaying useful optical properties
Sydnone C-4 heteroarylation with an indolizine ring via Chichibabin indolizine synthesis
The synthesis of sydnones heteroarylated at C-4 with an indolizine was achieved by Chichibabin (Tschitschibabin) indolizine synthesis starting from the corresponding sydnone-N-pyridinium bromides. The latter compounds were also transformed to sydnone-indolizines connected through a keto group at the C-4 position by refluxing them in 1,2-epoxybutane with an activated alkyne. The structures of the new compounds were assigned by FTIR, NMR spectroscopy and X-ray analysis
Indolizines and pyrrolo[1,2- c ]pyrimidines decorated with a pyrimidine and a pyridine unit respectively
The three possible structural isomers of 4-(pyridyl)pyrimidine were employed for the synthesis of new pyrrolo[1,2-c]pyrimidines and new indolizines, by 1,3-dipolar cycloaddition reaction of their corresponding N-ylides generated in situ from their corresponding cycloimmonium bromides. In the case of 4-(3-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine the quaternization reactions occur as expected at the pyridine nitrogen atom leading to pyridinium bromides and consequently to new indolizines via the corresponding pyridinium N-ylides. However, in the case of 4-(2-pyridyl)pyrimidine the steric hindrance directs the reaction to the pyrimidinium N-ylides and, subsequently, to the formation of the pyrrolo[1,2-c]pyrimidines. The new pyrrolo[1,2-c]pyrimidines and the new indolizines were structurally characterized through NMR spectroscopy. The X-ray structures of two of the starting materials, 4-(2-pyridyl)pyrimidine and 4-(4-pyridyl)pyrimidine, are also reported
Synthesis, characterization and antitumor activity of Cu(II), Co(II), Zn(II) and Mn(II) complex compounds with aminothiazole acetate derivative
This paper presents the synthesis of complex compounds of type [M(L1)(2)], where M(II) = Cu (1), Co (2), Zn (3), L1 = 2-aminothiazole-4-acetate and [Mn(L1)(2)(H2O)] (4) using ethyl 2-(2-aminothiazole-4-yl) acetate (L), and characterization by elemental analysis, magnetic susceptibilities, IR, 1H-NMR, UV-Vis spectroscopy and for [Mn(L1)(2)(H2O)] also by X-ray diffraction. In vitro cytotoxicity studies were performed on human cervix adenocarcinoma, HeLa cells. The antitumor selectivity was assessed using normal human peripheral blood mononuclear cells, PBMC as control
Assessment of textural differentiations in forest resources in Romania using fractal analysis
Deforestation and forest degradation have several negative effects on the environment including a loss of species habitats, disturbance of the water cycle and reduced ability to retain CO2, with consequences for global warming. We investigated the evolution of forest resources from development regions in Romania affected by both deforestation and reforestation using a non-Euclidean method based on fractal analysis. We calculated four fractal dimensions of forest areas: the fractal box-counting dimension of the forest areas, the fractal box-counting dimension of the dilated forest areas, the fractal dilation dimension and the box-counting dimension of the border of the dilated forest areas. Fractal analysis revealed morpho-structural and textural differentiations of forested, deforested and reforested areas in development regions with dominant mountain relief and high hills (more forested and compact organization) in comparison to the development regions dominated by plains or low hills (less forested, more fragmented with small and isolated clusters). Our analysis used the fractal analysis that has the advantage of analyzing the entire image, rather than studying local information, thereby enabling quantification of the uniformity, fragmentation, heterogeneity and homogeneity of forests
Sinteza, caracterizarea şi evaluarea fitobiologică a unei noi 2-[4-(4-bromofenilsulfonil) fenil]-4-metiloxazol - 5(4H)-one şi a unor noi 5-aril -2-[4-(4-bromofenilsulfonil) fenil]- 4-metiloxazoli
“Carol Davila“ University of Medicine and Pharmacy, Faculty of Pharmacy, Bucharest, Romania, Romanian Academy, “Costin D. Nenitescu“ Centre of Organic Chemistry, Bucharest, RomaniaPurpose. Heterocyclic compounds containing
1,3-oxazol-5(4H)-one and 1,3-oxazole ring are important
targets in synthetic and medicinal chemistry,
because of their applications as potentially active compounds.
Thus, some 1,3-oxazol-5(4H)-ones have been
reported to present antimicrobial and antitumor activity.
1,3-Oxazoles are frequent substructures in various
biologically active compounds used in therapeutics as
anti-inflammatory (e.g. Oxaprozin, Romazarit, Ditazol,
Isamoxole), analgesic (e.g. Oxaprozin), antibacterial,
antifungal (e.g. Sulfamoxole, Sulfaguanole), muscle
relaxant (e.g. Azumolene) drugs. Therefore, there
is considerable interest to synthesize new 1,3-oxazole-
5(4H)-ones and 1,3-oxazoles which contain 4-(4-bromophenylsulfonyl)
phenyl moiety in 2 position with a
hope to obtain potent biologically active compounds.
The plant growth regulatory effects of the new compounds
were examined.
Material and Methods. By Steiger N-acylation of
α-alanine with 4-(4-bromophenylsulfonyl)benzoyl
chloride at cool afforded 2-[4-(4-bromophenylsulfonyl)
benzamido] propanoic acid. This compound
underwent intramolecular cyclization in the presence
of N-methylmorpholine and ethyl chloroformate
or acetic anhydride to the corresponding saturated
azlactone. Then, acylaminoacylation of dry aromatic
hydrocarbons (benzene, toluene, m-xylene, mesitylene)
with 2-[4-(4-bromophenylsulfonyl)phenyl]-4-
methyloxazol-5(4H)-one or 2-[4-(4-bromophenylsulfonyl)
benzamido]propanoyl chloride in the presence
of anhydrous aluminum chloride led to N-(1-aryl-1-
oxopropan-2-yl)-4-(4-bromophenylsulfonyl)benzamides.
These new intermediates were heterocyclized
under the action of phosphorus oxychloride or concentrated
sulfuric acid in the presence of acetic anhydride
in ethyl acetate to the corresponding 5-aryl-2-[4-
(4-bromophenylsulfonyl)phenyl]-4-methyloxazoles.
The structure of new compounds was confirmed by
elemental analysis and different spectral methods
(FT-IR, UV, MS, 1H- and 13C-NMR). The purity of
the compounds was evaluated by RP-HPLC. The new
compounds have been investigated for their biological
activities in the growth regulation of wheat, using the
phytobiological method, known as the Constantinescu
bioassay – Triticum test.
Results. Ten new compounds were synthesized
and characterized in orther to evaluate their biological
activity. The preliminary results indicated that the tested
compounds exhibited a weak stimulatory activity,
except of α-acylaminoketones.
Conclusions. In conclusion, in this paper we described
the synthesis, characterization and phytobiological
activity of ten new compounds possessing the
4-(4-bromophenylsulfonyl)phenyl moiety
Recent Deforestation Pattern Changes (2000-2017) in the Central Carpathians:A Gray-Level Co-Occurrence Matrix and Fractal Analysis Approach
The paper explores the distribution of tree cover and deforested areas in the Central Carpathians in the central-east part of Romania, in the context of the anthropogenic forest disturbances and sustainable forest management. The study aims to evaluate the spatiotemporal changes in deforested areas due to human pressure in the Carpathian Mountains, a sensitive biodiverse European ecosystem. We used an analysis of satellite imagery with Landsat-7 Enhanced Thematic Mapper Plus (Landsat-7 ETM+) from the University of Maryland (UMD) Global Forest Change (GFC) dataset. The workflow started with the determination of tree cover and deforested areas from 2000–2017, with an overall accuracy of 97%. For the monitoring of forest dynamics, a Gray-Level Co-occurrence Matrix analysis (Entropy) and fractal analysis (Fractal Fragmentation-Compaction Index and Tug-of-War Lacunarity) were utilized. The increased fragmentation of tree cover (annually 2000–2017) was demonstrated by the highest values of the Fractal Fragmentation-Compaction Index, a measure of the degree of disorder (Entropy) and heterogeneity (Lacunarity). The principal outcome of the research reveals the dynamics of disturbance of tree cover and deforested areas expressed by the textural and fractal analysis. The results obtained can be used in the future development and adaptation of forestry management policies to ensure sustainable management of exploited forest areas
New Potential Antitumor Pyrazole Derivatives: Synthesis and Cytotoxic Evaluation
New pyrazole derivatives were designed and synthesized as potential protein kinase inhibitors in the view to develop specific antitumor therapies. The structures of the compounds were elucidated using spectral and elemental analyses. The antitumor potential was estimated using wheat seeds and the general toxicity was evaluated by alternative methods, using invertebrate animals. One 3-aminopyrazole derivative emerged as a potential candidate for the development of future cytotoxic compounds
The Role of Molecular Descriptors as Screening Tools for the Pyridinealdoxime Methiodide Derivatives Biopharmaceutical Profile
The paper presents an analysis of molecular descriptors with biological relevance for three series of pyridinealdoxime methiodide (2-PAM) analogues with potentially improved permeability characteristics. The biopharmaceutical profile is discussed by correlation with predicted solubility in various simulated biological fluids and permeability across several types of biological barrier. The data suggests that the increase in lipophilicity could be considered as a good approach in optimization of the low permeability profile determined by the highly polar structure, necessary for the reactivation of organophosphorous compounds inhibited cholinesterase
- …