Novel symmetric bis-benzimidazoles: Synthesis, DNA/RNA binding and antitrypanosomal activity.

The novel benzimidazol-2-yl-fur-5-yl-(1,2,3)-triazolyl dimeric series with aliphatic and aromatic central linkers was successfully prepared with the aim of assessing binding affinity to DNA/RNA and antitrypanosomal activity. UV-Visible spectroscopy, thermal denaturation showed interaction of heterocyclic bis-amidines with ctDNA. Circular dichroism studies indicated uniform orientation of heterocyclic bis-amidines along the chiral double helix axis, revealing minor groove binding as the dominant binding mode.

Synthesis, anti-bacterial and anti-protozoal activities of amidinobenzimidazole derivatives and their interactions with DNA and RNA.

Amidinobenzimidazole derivatives connected to 1-aryl-substituted 1,2,3-triazole through phenoxymethylene linkers 7a-7e, 8a-8e, and 9a-9e were designed and synthesised with the aim of evaluating their anti-bacterial and anti-trypanosomal activities and DNA/RNA binding affinity. Results from anti-bacterial evaluations of antibiotic-resistant pathogenic bacteria revealed that both o-chlorophenyl-1,2,3-triazole and N-isopropylamidine moieties in 8c led to strong inhibitory activity against resistant Gram-positive bacteria, particularly the MRSA strain. Furthermore, the non-substituted amidine and phenyl ring in 7a induced a marked anti-bacterial effect, with potency against ESBL-producing Gram-negative E.

New quinoline-arylamidine hybrids: Synthesis, DNA/RNA binding and antitumor activity.

Four series of new hybrid molecules with 7-chloroquinoline and arylamidine moieties joined through the rigid -O- (groups I (2a-g) and II (5a-g)) or flexible -NH-CH-CH-O- (groups III (8a-g) and IV (10a-g)) linker were synthesized, and their DNA/RNA binding properties and cytotoxic activity were tested, against several human cancer lines. The compounds and their interaction with DNA and RNA were studied by UV-Vis and CD spectroscopy. The obtained results showed that the binding affinity of the investigated compounds increases proportionally with the increase of the length and number of groups able to form hydrogen bonds with ds-polynucleotides.

An Aromatic Diamidine That Targets Kinetoplast DNA, Impairs the Cell Cycle in Trypanosoma cruzi, and Diminishes Trypomastigote Release from Infected Mammalian Host Cells.

Trypanosoma cruzi is the etiological agent of Chagas disease, affecting approximately 10 million people in the Americas and with some 40 million people at risk. The objective of this study was to evaluate the anti-T. cruzi activity of three new diamidines that have a 3,4-ethylenedioxy extension of the thiophene core, designated MB17, MB19, and MB38.

Mechanistic investigation of charge-remote and charge-driven fragmentation processes in 2,5-diphenyl-3,4-ethylenedioxythiophene diamidines.

Rationale: Diphenylfuran diamidines represent an important class of DNA minor groove binders of high therapeutic interest as antitumor and antibacterial agents. This study aimed to investigate fragmentation patterns in mass spectra of four diamidine derivatives with significant antitumor activity, in order to gain more insight into the structures and stability of their putative biological metabolites.

Methods: Compounds were investigated by electrospray ionization tandem mass spectrometry (ESI-MS/MS) using low-energy collision-induced dissociation (CID).

Synthesis and structure-activity relationship of amidine derivatives of 3,4-ethylenedioxythiophene as novel antibacterial agents.

Current antibacterial chemotherapeutics are facing an alarming increase in bacterial resistance pressuring the search for novel agents that would expand the available therapeutic arsenal against resistant bacterial pathogens. In line with these efforts, a series of 9 amidine derivatives of 3,4-ethylenedioxythiophene were synthesized and, together with 18 previously synthesized analogs, evaluated for their relative DNA binding affinity, in vitro antibacterial activities and preliminary in vitro safety profile. Encouraging antibacterial activity of several subclasses of tested amidine derivatives against Gram-positive (including resistant MRSA, MRSE, VRE strains) and Gram-negative bacterial strains was observed.

2-(4-Amino-phen-yl)-3,4,5,6-tetra-hydro-pyrimidin-1-ium chloride.

In the title compound, C(10)H(14)N(3) (+)·Cl(-), the tetra-hydro-pyridinium ring of the cation, which adopts a slightly distorted envelope conformation, is disordered over two orientations with an occupancy ratio of 0.653 (5):0.347 (5).

Fragmentation of diamide derivatives of 3,4-ethylenedioxythiophene.

The sequential product ion (MS(n)) fragmentation of four symmetric diamide derivatives of 3,4-ethylenedioxythiophene were characterized using ion trap mass spectrometry with electrospray ionization and their fragmentation patterns were studied. The experimental data consists of mass spectra obtained by tandem mass spectrometry, and calculations were obtained by the M06-2X/6-31 G (d,p) method. Investigated compounds represent building blocks in synthesis of compounds used in different areas of chemistry and industry such as in medicinal chemistry, as potential anticancer and anticonvulsant agents, in organic chemistry as linkers for solid-phase synthesis, and in the synthesis of a variety of materials in polymer chemistry.

Bis[2-(4-amino-phen-yl)-4,5-dihydro-1H-imidazol-3-ium] dichloride monohydrate.

The asymmetric unit of the title compound, 2C(9)H(12)N(3) (+)·2Cl(-)·H(2)O, comprises two mol-ecules, two chloride anions and one mol-ecule of crystal water. In the imidazolinium ring, the protonation contributes to delocalization of the positive charge over the two C-N bonds. Both chloride anions are acceptors of four hydrogen bonds in a flattened tetra-hedron environment.

Synthesis, DNA/RNA affinity and antitumour activity of new aromatic diamidines linked by 3,4-ethylenedioxythiophene.

A series of novel 2,5-bis(amidinophenyl)-3,4-ethylenedioxythiophenes (5-10 and 15) has been synthesized. Compounds 5-10 bind to the DNA minor groove as the dominant binding site and strongly stabilize the double helix of ct-DNA. Surprisingly, the same compounds also thermally stabilize ds-RNA, whereby most of them form stacked dimers along the RNA double helix.

Effect of 3,4-ethylenedioxy-extension of thiophene core on the DNA/RNA binding properties and biological activity of bisbenzimidazole amidines.

Novel bisbenzimidazoles (4-6), characterized by 3,4-ethylenedioxy-extension of thiophene core, revealed pronounced affinity and strong thermal stabilization effect toward ds-DNA. They interact within ds-DNA grooves as dimmers or even oligomers and agglomerate along ds-RNA. Compounds 4-6 have shown moderate to strong antiproliferative effect toward panel of eight carcinoma cell lines.

Significance of proto-oncogene Bcl-X(S/L) expression in Wilms tumor.

Unlabelled: The rate of apoptosis varies in malignant tumors, and it can be involved in diminishing tumor size. Different protein-regulators of apoptosis, such as Bcl-2, BclX, and Bax have an influence on the rate of apoptosis in various tumors. In human renal diseases, such as the experimental model of acute renal failure, and many tumors, including Wilms' tumor, the expression of antiapoptotic members of Bcl-2 family is increased, while the expression of proapoptotic members is low.

[Effect of donor-specific blood transfusion on the outcome of kidney transplantation].

Donor specific transfusion (DST) is proclaimed to improve graft survival in living related kidney transplantation (LRTx). The aim of the present study was to estimate the influence of DST on LRTx graft function, acute rejection rate (AR) and survival in the early and late posttransplant period. Fifty-five LRTx patients (grafted in the same year, and matched for recipients' and donor's age, sex) were included into the study.

[Significance of blood transfusion in the development of cytotoxic antibodies in patients on hemodialysis].

The aim was to evaluate the influence of red blood cells (RBC) transfusion on the development of cytotoxic antibodies (C-Ab) in patients subjected to hemodialyses (HD) and planned for the kidney transplantation. The group of 71 HD patients, of mean age 42 years (19-65), 48 males and 23 females, planned for the kidney information was examined. Out of 71 HD patients, only 42 (59.

Histocompatibility antigens in patients with hepatocellular carcinoma.

The distribution of class I (A, B, C) and class II (DR antigens) histocompatibility antigens (HLA) was examined in 82 patients with hepatocellular carcinoma (HCC) and in 147 patients with chronic liver disease as controls. The diagnosis of HCC was confirmed by histological examination of liver tissue. HLA-B15 antigen was found more frequently in the subgroup of HCC patients who were positive for HBsAG (13/36, 36.

[Kidney transplantation in high-risk patients].

Immunosuppression with Cyclosporine A in kidney transplantation, triple therapy (CyA + Imuran + corticosteroids) and plasmapheresis before and after kidney transplantation in high risk recipients (positive cytotoxic antibody, MLC at the level of non related persons), also in high risk patients (juvenile diabetes, patients over 50 years old). In 1988 we had done in our Centre, kidney transplantation in 52.8% (28: 53) in high and increased risk patients.