Biomedical subjects

Rita Szabó

Publications and source records attributed to Rita Szabó.

3 recordsLinked to original sources

PubMed2006

Synthesis, structure, and in vitro antitumor activity of some glycoside derivatives of ferrocenyl-chalcones and ferrocenyl-pyrazolines.

Some new glycosides of 3-ferrocenyl-1-(4'-hydroxyphenyl)-prop-2-en-1-one were prepared and transformed into the corresponding pyrazoline and pyrazole derivatives. Using methyl-hydrazine, formation of regioisomers was observed. DDQ was found to be a mild and efficient reagent for the pyrazoline-pyrazole dehydroaromatization process. The structure of the new compounds was proved by IR and NMR spectroscopy. The in vitro antitumor activity of the substances was investigated against human leukemia (HL-60) cells by the MTT method. Among these new compounds some chalcone derivatives (3 a, 3 b, 5 a, and 5 b) showed attractive in vitro antitumor effects on human leukemia cells. These molecules contained ferrocenyl moieties and a p-hydroxy-phenolic ring or a size-independent apolar substitution of that.

Antineoplastic Agents↗

PubMedDate not supplied

Drug targeting by macromolecules without recognition unit?

his review will summarize available information on the ability of macromolecular conjugates containing no specific recognition motifs to deliver anthracyclines (daunomycin, adriamycin) or methotrexate to target cells such as tumour cells or macrophages. Conjugates with natural (proteins, DNA, carbohydrates) and synthetic macromolecules (linear and branched chain poly-alpha-amino acids, non-biodegradable DIVEMA, HPMA etc.) will be reviewed. Experimental data from several laboratories indicate that these conjugates are taken up by cells mainly by fluid-phase or adsorptive endocytosis. It is believed that these processes do not involve 'specific receptors'. Two examples of methotrexate and daunomycin conjugates will be discussed to show the effect of the chemical structure of branched chain polypeptides on the uptake and antitumour or antiparasitic (Leishmania donovani infection) efficacy of conjugates.

Animals↗

PubMedDate not supplied

Uptake of branched polypeptides with poly[L-lys] backbone by bone-marrow culture-derived murine macrophages: the role of the class a scavenger receptor.

Selective delivery of antiparasitic or antibacterial drugs into infected macrophages could be a promising approach for improved therapies. Methotrexate conjugate with branched chain polypeptides exhibited pronounced anti-Leishmania activity in vitro and in vivo as reported here earlier. To identify structural requirements for efficient uptake of branched polypeptides, we have studied murine bone marrow culture-derived macrophages (BMMphi) from 129/ICR mice. We report on the translocation characteristics of structurally closely related compounds labeled with 5(6)-carboxyfluorescein. We found that this process is dependent on experimental conditions (e.g. polypeptide concentration, incubation time, and temperature). Using specific inhibitors as well as macrophages from wild-type and class-A scavenger receptor knockout (SR-A -/-) mice, we demonstrated that SR-A was involved in the endocytosis of some polypeptides depending on their charge. Uptake could be blocked by unlabeled polypeptide, by SR-A inhibitors, and by specific anti-SR-A monoclonal antibody. The polyanionic polypeptide poly[Lys(Succ-Glu(1.0)-dl-Ala(3.8))] (SuccEAK) with high charge density translocated more efficiently than poly[Lys(Ac-Glu(1.0)-dl-Ala(3.8))] (AcEAK), which had a lower anionic charge density. On the basis of experimental data presented, SuccEAK can be considered as a potential candidate for the design of a macromolecular carrier for specific drug delivery of bioactive entities into macrophages via SR-A.

Animals↗