Prof. Mariana Mitewa

Laboratory of Biocoordination and Bioanalytical Chemistry (LBBC)

Staff:   Prof. Mariana Mitewa, D.Sci.

Assist. Prof.: Dr. Ivayla Pantcheva, Anife Ahmedova, Vasil Atanasov

PhD / MSci students: Petar Dorkov, Rumyana Zhorova, Christo Kolev


I. One of the main areas of interest of the Laboratory of BBC is focused on the study of complexation processes of biologically active compounds with various metal ions in order to improve the biological activity of the ligands studied. The coordination properties of some antibiotics applied in veterinary medicine are studied towards biometal ions as Ca, Mg, Cu, Co, Zn, as well as the coordination of these antibiotics with toxic metal ions (Cd, Hg) was also evaluated.

The main challenges in this field can be summarized as follows:

1. An increase in antimicrobial activity of new biometal complexes compared to non-coordinated antibiotics is observed; this is a result which is pointed out to the possible application of these new compounds in veterinary medicine as more potent drugs

2. The complex formation using heavy metal ions can be applied in the case of acute intoxication possible to occur in the stock farming.

II. The crucial importance of the structure of the synthesized metal complexes is the focus of combined theoretical (quantum-chemical) and spectroscopic studies aiming at giving proper description of the structure-activity relationship. Part of these studies involves a series of polyketones with interesting optical properties (including crown ether derivatives) and the structure and properties of their metal complexes. Another class of compounds subjected to theoretical (HF and DFT) and experimental (X-Ray diffraction, XPS, EPR, NMR, IR, UV-Vis spectroscopy) description is a series of hydantoins and their thio-analogues. Their complexation ability with metal ions, such as Cu(II), Ni(II), Pt(II), Ru(III), is studied also with respect to their potential application as anticancer drugs. The experimental spectroscopic data are used to verify the theoretically suggested structure for the complexes (if no crystallographic analysis is applicable) by direct comparison with the quantum-chemically calculated spectroscopic properties using GIAO and/or TD-DFT methods.

III. Two main fields of bioanalytical studies are developed in the LBBC. The first one is focused on studying of biochemical and toxicological properties of the vipoxin and its components. The second one is focused in analytical toxicology – studying of stability of benzodiazepines in biological samples and their post-mortem biotransformations. The LBBC is the only one of its kind in Bulgarian universities authorized to perform studies using narcotics and drugs of abuse. In the Laboratory the following studies in the field of bioanalytical chemistry, toxinology and analytical toxicology can be performed: protein isolation, purification and analysis; analysis of blood (clinical chemistry); testing of newly synthesized compounds and their metal complexes for target inhibition of pathologically significant enzyme systems; snake venom toxins (Vipera ammodytes); toxins affecting blood coagulation and hemotoxicity; analysis of drugs and metabolites in biological samples; stability of drugs in biological samples and post-mortem biotransformations.

Wide spread collaboration with many Bulgarian and foreign researchers is realized.

I. N. Pantcheva, R. Zhorova, M. Mitewa, S. Simova, H. Mayer-Figge, W. S. Sheldrick, BioMetals 23(1) (2010) 59-70. DOI: 10.1007/s10534-009-9269-5

I. N. Pantcheva, P. Dorkov, V. N. Atanasov, M. Mitewa, B. L. Shivachev, R. P. Nikolova, H. Mayer-Figge, W. S. Sheldrick. J. Inorg. Biochem., 103 (10), 1419-1424, 2009.

V. N. Atanasov, D. Danchev, M. Mitewaand S. Petrova., Biochemistry (Moscow) 74 (3), 339-345, 2009.

V. N. Atanasov, K. P. Kanev, M. Io. Mitewa, Cenr. Eur. J. Med. 3 (3), 327-331, 2008.

A. Ahmedova, P. Marinova, S. Ciattini, N. Stoyanov, M. Springborg, M. Mitewa, Struct. Chem. 20 (2009) 101-111.

A. Ahmedova, P. Marinova, K. Paradowska, M. Marinov, I. Wawer, M. Mitewa, Polyhedron 29 (2010) 1639-1645