[In vitro antimicrobial activity of new 1,10-phenantroline derivatives]

The antimicrobial and antifungical activities of some 1,10-phenanthroline derivatives are described. The test was performed using the diffusimetric method with stainless steel cylinders based on diffusion of the substances on the gelose surface for bacteria and Sabouraud field for Candida Albicans yeast. The comparative analysis of the obtained data leads to the following conclusions concerning the relation between structure and activity

[New derivatives of 1-methyl-phthalazine with antimicrobial and fungistatic action]

In this paper we present the antimicrobial and antifungical action of some new salts of 1-methyl-phtalaziniums and their corresponding ylids. We also present conclusions concerning the relation between structure and biological activity. The test was performed using the diffusimetric method with rustless steel cylinders based on the diffusion on the tested substances on gelose surface. The salts of 1-methyl-phtalaziniums are always more active comparatively than their corresponding ylids. All the compounds but not all derivatives are more active on the Candida albicans.

Prodrugs of CL316243: a selective beta3-adrenergic receptor agonist for treating obesity and diabetes

CL316243 is a highly selective and potent beta3-adrenergic receptor agonist, and has been shown in rodent models to be an effective agent for treating obesity and Type II diabetes. To improve the oral absorption and pharmacokinetic profiles of CL316243, a number of prodrugs have been synthesized and evaluated. Several ester-type prodrugs show significant improvements in oral bioavailability in both rodent and primate models.

Tetrazolium salts and metal complexes of some formazans

This paper presents the synthesis of some tetrazolium salts and metal complexes combinations, which are derived from aromatic and heterocyclic formazans. Elemental quantitative analyses and spectral data confirmed the structure of the new synthesized compounds. The new synthesized compounds were submitted to microbiological tests.

[Antimicrobial activity of some derivatives of pyrimidine]

In this paper the authors present the antimicrobial and antifungical tests of some new 3-methylpyrimidine compounds. The test was performed using the diffusimetric method with rustlessteel cylinders based on the diffusion of the tested substances on the gelose surface. The comparative analysis of the obtained data leads to the following conclusions concerning the relation between structure and biological activity in the pyrimidine series: 1. The pyrimidinium ylides are less active comparatively with the corresponding salts. That means that the zwitter ionic structure did not favour the activity. 2. Comparative with the corresponding pyridazine(1,2-diazine) derivatives, the pyrimidine(1,3-diazine) compounds are more active. The increase of activity of the pyrimidine compounds could be attributed of the influence of the pyrimidine ring. 3. The most active pyrimidine compound which is tested is that one in which radical R is an amide group. 4. In the case when the radical R is a phenyl ring, the substitute from para position of benzoylic radical does not appear decisive towards activity, these affecting especially the selectivity.

[Hydrazide derivatives with biologically active 1,2,4-triazole support]

This study presents the synthesis of ten new hydrazides with 1,2,4-triazole support. The structures of the obtained compounds were elucidates by means of the elemental analysis data as well as by IR spectral measurements. The antimicrobial and antifungal actions of this derivates are also tested. The results show that the compounds with the functional group 4-chlore-2-methoxyphenyle are more active.

Hydrazones and formazans with possible biological activity

This paper presents a synthesis about some hydrazones, formazans and copper's complexes combinations. The structure of the new compounds was confirmed by the results of the quantitative elementary and IR spectral analysis. The antimicrobial and antiinflammatory activities were investigated.

[Antimicrobial activity of new pyridazine derivatives]

Continuing the investigations concerning synthesis-structure-biological activity in the pyridazine series, the results of the antimicrobial and antifungal tests of some new pyridazinium compounds are presented. The test was performed using the diffusimetric method with rustles steel cylinders based on the diffusion of the tested substances on the gelose surface. The comparative analysis of the obtained data leads to the following conclusions concerning the relation between structure and activity in the pyridazine series: 1. The cis-isomers are always more active comparatively with similar trans- isomers: 2. In the pyrrolopyridazine series we remark that the saturated or partial saturated compounds have always a stronger activity as the related aromatics derivatives. We also noticed that the saturated, partial saturated and aromatic compounds have different selectivity. Thus, the saturated are more active on the Pseudomonas aeruginosa and Candida albicans, the partial saturated are more active on the Staphylococcus aureus and Bacillus subtilis while the aromatic compounds are active on the Bacillus subtilis. 3. The influence of the Y-substitutes of para position of benzoylic radical and the substitutes of pyrrolo ring is not decisive towards activity, these affecting especially the selectivity.

Visual processing of configuration-dependent spatial characteristics of shapes and patterns. A model useful in the study of the role of the departure from circularity or dispersion of shapes in human visual perception

In this work a theoretical model was used in combination with testings on normal subjects to get more insight in the role of the departure from circularity or dispersion of the shapes in visual perception. The model was inspired by the observation that the intensity of the effect of a given level of contrast of a shape usually increases, for the same area, with the shape being better concentrated around a center. The model introduces as a measurable characteristic the degree of concentration or dispersion of a shape with respect to a center. The measure was based on the maximum of the convolution integral of the characteristic function of the shape with the weighting function 1/2 pi r, r being the distance between the point of convolution and the surface element to be integrated. A program for the calculation of the degree of concentration of figures and other related processing operations was developed in Turbo Pascal language on a 486 PC. The program included the possibility to generate various figures and to operate on them various transformations such as strangulation, fragmentation with separation of fragments. The model introduces a center of the figure, the point best surrounded by the whole figure, with a geometric and visual significance, as resulting from the good concordance between its calculated and perceived positioning in different relatively simple shapes. In symmetrical compact figures subjected to a central separation or narrowing two centres appear entering the two resulting nuclear parts; a good concordance between model and perception was again observed in this transition to two centres and their subsequent positions in the two nuclear parts. In accord to model prediction, testings showed a very pronounced dependence of the summation efficiency over a contrasting area on the degree of dispersion of the area. This is reflected in the drastic decrease upon figure dispersion of the intensity with which a given brightness or colour contrast is perceived. Thus, the model gives a better explanation and a more efficient way to approach the great capacity of the visual system to disclose more compact shapes or agglomeration zones in a complex visual scene. This capacity is to a large extent due to the increase in the intensity with which a given contrast is perceived, occurring in these conditions. This intensity, which strongly depends on the degree of concentration or dispersion of the figure, becomes an important additional signal leading to the accentuation of the difference between compact and rarefied shapes. The model based on the degree of concentration determined around a centre, although useful for finding a centre and applicable satisfactorily to many shapes, do not cover well all aspects of shape dispersions. In shapes without a dominant central part the confrontation model-testing showed an important involvement in global perception of all local concentrations, not only central but also peripheral, the later underestimated in our model. The model can be however improved by taking into account also such local concentrations.

[The synthesis and biological activity of new disubstituted carbanion ylides from pyridazine]

Continuing the investigations in view obtaining new carbon-nitrogen stable dissiniu-ilydes, were obtained new 3-phenyle-pyridaziniu-ylides carbanion disubstituted. The antimicrobial and antifungus action of the products VIa, VIb, VIIa, VIIb and VIIc also studied.

[The antibacterial action of new hydrazide derivatives]

New derivatives of 4-aminobenzoic and 4-chlorine-2-hydroxybenzoic acids hydrazides were synthesized by the condensation reaction of these hydrazides with aldehydes and ketones, derivatives containing in their molecule azometine and hydrazone groups. The obtained products are potentially bioactive. The study of their "in vitro" biological activity was performed on some pathogenic germs, both gram-positive and gram-negative. The results show that the tested substances are more active towards the gram-positive germs.

[Phthalazinilides. The action of ethyl bromopyruvate on phthalazine]

Our investigation for obtaining carbon-nitrogen stable ilides continued by the synthesis of new phthalazinic derivatives by the action of ethyl brompyruvate. The structure of the obtained products was confirmed by chemical and spectral analyses. The results regarding their antimicrobial action are also presented.

[Ilide derivatives of pyridazines with biological activity]

Continuing the investigations on the synthesis and pharmacodynamic action of some pyridaziniu-ilides, this paper presents the results of the preliminary investigations on the antimicrobial activity of the synthetized products. Their action against Staphylococcus aureus Oxford and the anti-yeast action of the cycloimonium salts is underlined.