NMR Spectroscopy investigations started in Bulgaria in 1966 at
the Institute of Organic Chemistry, Bulgarian Academy of Sciences. A CW JEOL
instrument with working frequency 60 MHz was the first NMR spectrometer
installed and it was in use until May 1981. In 1977 and 1978 two more CW NMR
spectrometers – Tesla 80 MHz and 60 MHz,
respectively, were purchased. The expertise of the scientists contributed to the
broader implementation of the method in the country.
During that period several more CW NMR instruments were
installed in other research institutions in Bulgaria such as the Technical
University of Chemistry, the Faculty of Chemistry at the Sofia University, the
Institute of Chemical Technology, the Faculty of Pharmacy at the Medical
University and the Faculty of Chemistry at the University of Plovdiv. Most of
these instruments are now out of operation and if not, preliminary information
only can be obtained.
In 1981 high resolution pulse NMR instrument with cryomagnet was installed
in the Institute of Organic Chemistry, Bulgarian Academy of Sciences. The new
spectrometer - Bruker WM 250, with a working frequency of 250 MHz, was supplied
as part of a project between the Bulgarian Government and UNDP UNESCO for
founding a Centre of Phytochemisty. Considerable enhancement of the RTD capacity
and capability has been achieved by expanding the research topics and areas and
starting new investigations of methodological, analytical and practical aspects.
At that time the NMR spectrometer in the Institute of Organic Chemistry with
Centre of Phytochemistry was the most up-to date spectrometer in the vast region
of the Balkan Peninsula. The improvement of the
scientific equipment opened new opportunities for collaboration with industrial
partners by offering analytical expertise and services to pharmaceutical, food
and cosmetic companies. Application of NMR spectroscopy for identification and
quality control of various formulations, intermediates and final products
In 1994 the spectrometer cabinet was upgraded to the digital model Avance
DRX, which contributed further to the evolution of NMR spectroscopy studies in
Bulgaria. The application of 2D NMR spectroscopy and selective 1D experiments
have been made routinely available. A new more sensitive (~30%) dual
probehead has been put into operation, leading
to a considerable speed-up of research and service routine.
In 2005 the Institute of Organic Chemistry with Centre of
Phytochemistry together with six academic institutions from the country set up a
consortium, which has been awarded financial
support in the framework of the Program “Promotion of the Research Potential
through Unique Scientific Equipment” launched by the Ministry of Education and
Science, Bulgaria. An advanced NMR spectrometer Bruker Avance II+ 600 for
investigation of samples in the liquid and solid state was purchased and
installed in February 2007 in the Institute in fully refurbished and
reconstructed rooms. At the same time the existing Bruker DRX 250 spectrometer
was upgraded for gradient work and supplied with more up-to date software. The
two spectrometers are integrated in the local network of the Institute, which
ensures easy, fast and convenient access for downloading the spectra.
In 2009 the infrastructure project “Bulgarian NMR Centre – Development of
Advanced and Effective Research Infrastructure for NMR Analysis of Bio- and
Nanomaterials “ has been funded from the National Science Fond.
of the proposed project is building of an advanced and effective Nuclear
Research Infrastructure based on the state-of-the-art research equipment and the
integrated knowledge, expertise and research capacity of the Institute of
Organic Chemistry with Centre of Phytochemistry, Institute of Polymers,
Institute of General and Inorganic Chemistry at the Bulgarian Academy of
Sciences and the Chemical Faculty, Sofia University
Since 2007 the refurbished and upgraded NMR laboratory at the
Institute of Organic Chemistry with Centre of Phytochemistry, equipped with two
advanced NMR spectrometers has been in a process of transition to a Bulgarian
NMR Centre. This NMR Centre possesses highly qualified and experienced staff,
involved in a number of research and applied projects and offering service
analyses, teaching and training of students and researchers, as well as high
scientific expertise for various research, academic and industrial institutions.
Combining research, education and practical application, the Bulgarian NMR
centre opens new perspectives for research, development and innovation in the
priority areas of the 7th EC
Food, Agriculture and Fisheries,
Information & communication
materials & new production technologies;
firm basis for multi- and interdisciplinary projects with scientists and
industrial experts from the country and the international scientific community
has been founded.
Selected publications of the prominent scientists, that
introduced and promoted the methods and applications of NMR spectroscopy in
Prof. DSc. Stefan Spassov:
- S. Spassov “NMR Spectra, Configuration and Conformation of
Diastereomers: 3-Substituted 2,3-Diphenylpropanoic Acids and Their Methyl
Esters”, Tetrahedron 25 (1969) 3631.
- E. Stanoeva, S. Spassov, M. Haimova and B. Kurtev,
“Stereochemie der 3,4-Disubstituirten 1,2,3,4-Tetrahydroisochinoline” Chem. Ber
109 (1976) 2972.
- S. Spassov, M. Lyapova and M. Ivanova, NMR Spectra and
Stereochemistry of Diastereoisomeric 4,5-Diphenylphosphamides. Phosphorus and
Sulfur 37 (1988) 199.
- G. I. Eneva, S. L. Spassov, M. A. Haimova and J.
Sandstroem, “Complete 1H
and 13C NMR Assignment for
Apramycin, Sisomicin and Some N- and N,O-Polyacetylated Aminoglycosides” Magn.
Reson. Chem. 30 (1992) 841.
- S. Simova, G. Ivanova and S. L. Spassov, “Alternative NMR
Method for Quantitative Determination of Acyl Positional Distribution in
Triacylglycerols and Related Compounds” Chem. Phys. Lipids 126 (2003) 167.
- V. S. Dimitrov, “Dynamic NMR: Integral Parameter Sensitivities
and Their Use in the Total Line Shape Analysis” J. Magn. Reson. 22 (1976) 71.
- V. S. Dimitrov and J. A. Ladd, “A Double - Fitting Procedure for
Two-Site Exchange Analysis” J. Magn. Reson. 36 (1979) 401.
- E. Kupce, J-M. Nuzillard, V. S. Dimitrov and R. Freeman, “A New
Form of Correlation Spectroscopy” J. Magn. Reson. A, 107 (1994) 246.
- V. S. Dimitrov and N. G. Vassilev, “Dynamic NMR: A New Procedure
for the Estimation of Mixing Times in the 2D EXSY Experiments. A Four Site
Exchange System Studied by 1D and 2D EXSY Spectroscopy, Magn. Reson. Chem., 33
- P. S. Denkova and V. S. Dimitrov, “A Combined Usage of Complete
Line Shape Analysis of 1D Spectra Subjected to Reference Deconvolution and
Linear Prediction, 2D EXSY Spectra and Double Fitting Method for Studying
Chemical Exchange. Application to an Eight Site Exchange System”, Magn. Reson.
Chem., 37 (1999) 637.