Ivan Svinyarov

GA2015, Budapest, Hungary

Ivan Svinyarov

Personal information

First name / Surname: Ivan Svinyarov

Address (work):
Faculty of Chemistry and Pharmacy,
University of Sofia “St Kliment Ohridski”,
1, James Bourchier blvd.,1164 Sofia,
Bulgaria

Telephone: (+359 2) 81 61 228 (work)
Fax: (+359 2) 962 54 38 (work)
E-mail: ivansvinyarov@abv.bg, ohis@chem.uni-sofa.bg

Author ID (SCOPUS): 16744554800 
Research ID (Web of Science)L-9647-2015
 
ORCID ID0000-0003-1882-203X

 Professional experience

University of Sofia “St. Kl. Ohridski” / Faculty of Chemistry and Pharmacy / Department of  Organic Chemistry and Pharmacognosy                                               2017 – till now, Associate Professor in Pharmacognosy
2015 – 2017, Head Assistant Professor in Pharmacognosy
2013 – 2015, Assistant Professor in Pharmacognosy
2006 – 2011, Research Student at the Heterocyclic Chemistry Group

Main activities and responsibilities: Lecturer in “Pharmacognosy” (since 2016) • Conductor of practice in “Pharmacognosy” (since 2015) • Conductor of laboratory sessions and seminars in “Pharmacognosy” (since 2013) • Conductor of laboratory sessions and seminars in “Chromatographic Methods for Separation and Analysis” (since 2013) • Conductor of laboratory sessions and seminars in “Organic Chemistry” (since 2012)

Education

2012 – 2015, Graduated in 2015 as Philosophy Doctor (PhD) from University of Sofia “St. Kl. Ohridski”
Title of Thesis: Synthesis and biological activities of polysubstituted benzopyrones. Supervisor: Assoc. Prof. Dr. Milen Bogdanov, PhD. Principal subjects/occupational skills covered: Multi-step synthesis of heterocyclic compounds • Separation and structure elucidation of complex mixture • Conformational analysis • Radical scavenging and antioxidant activities.

2010 – 2011, Graduated in 2011 as Master of Science form University of Sofia “St. Kl. Ohridski”, Master’s program: Organic chemistry
Title of Thesis: Synthesis and biological activity of polysubstituted cis-/transN-hexyl 3,4-dihydroisocoumarin-4-carboxamide. Supervisor: Assoc. Prof. Dr. Milen Bogdanov, PhD

2005-2010, Graduated in 2010 as Bachelor of Science form University of Sofia “St. Kl. Ohridski”, Bachelor’s program: Chemistry
Title of Thesis: Synthesis and biological activity of polysubstituted cis-/trans-3,4-dihydroisocoumarin-4-carboxylic acids. Supervisor: Assoc. Prof. Dr. Milen Bogdanov, PhD

Research visits

University of Applied Sciences, Aalen, Germany – March 2007 – September 2008 (7 months)
Specialization in the group of Prof. Dr. W. Kantlehner. Principal subjects covered: Synthesis, characterisation, measurements of physico-chemical properties and application of guanidinium-based Ionic liquids

Institute of Chemical Process Fundamentals CAS, Prague, Czech Republic – Jun 2015 – July 2015, (1 month)
Short scientific mission in the group of M. Bendova, PhD. Principal subjects covered: Synthesis and measurements of physico-chemical properties of imidazolium-based ionic liquids

Scientific interests

Natural compounds • Medical plants • Drug design • Organic synthesis • Heterocyclic compounds • Ionic Liquids • Stereochemistry • Chromatography • Spectral methods • Conformational analysis

Professional and Scientific Awards

Best young scientist of University of Sofia “St. Kl. Ohridski” for 2017 • Award for PhD Thesis from Union of Scientist in Bulgaria for 2015 • Best Chemistry Student of University of Sofia “St. Kl. Ohridski” for 2014 • Best Chemistry Student of University of Sofia “St. Kl. Ohridski” for 2012 • Nomination for scholarship “Rostislav Kaishev” of Eureka Foundation for 2010 • Best Chemistry Student of University of Sofia, 2010 • Best Chemistry Student of University of Sofia “St. Kl. Ohridski” for 2008 • Award for Best Essay of the Department of Inorganic Chemistry of Sofia University “St Kliment Ohridski” for 2008

Membership in scientific organizations

Union of Chemists in Bulgaria • European Association for Chemical and Molecular Sciences • Federation of Scientific and Technical Unions 

Personal skills and competences

Organisational skills and competences: • Supervisor of undergraduate students • Team leader in scientific projects for application of ionic liquids as ionic liquids as extracting agents of natural products

Computer skills and competences: Competent at high level with: • Win XP/7 • Microsoft Office tools (Word, Excel and PowerPoint) • ChemOffice program package (ChemDraw, Chem3D, ChemFinder) • Crystallographic software (Olex2) • NMR spectroscopy software (MestReNova, TopSpin) • Chromatography software (LSChrom) • Design (Adobe Photoshop, QuarkXPress 9)

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Molecules 20 (2015) 2555-2575

Synthesis and antioxidant activity of polyhydroxylated trans-restricted 2-arylcinnamic acids
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A series of sixteen polyhydroxylated trans-restricted 2-arylcinnamic acid analogues 3a–p were synthesized through a one-pot reaction between homophthalic anhydrides and various aromatic aldehydes, followed by treatment with BBr3. The structure of the newly synthesized compounds was confirmed by spectroscopic methods and the configuration around the double bond was unequivocally estimated by means of gated decoupling 13C-NMR spectra. It was shown that the trans-cinnamic acid fragment incorporated into the target compounds’ structure ensures the cis-configuration of the stilbene backbone and prevents further isomerization along the carbon–carbon double bond. The antioxidant activity of compounds 3a–p was measured against 1,1-diphenyl-2-picrylhydrazyl (DPPH●), hydroxyl (OH●) and superoxide (O2●▬) radicals. The results obtained showed that the tested compounds possess higher activities than natural antioxidants such as protocatechuic acid, caffeic acid and gallic acid. Moreover, it was shown that a combination of two different and independently acting fragments of well-known pharmacological profiles into one covalently bonded hybrid molecule evoke a synergistic effect resulting in higher than expected activity. To rationalize the apparent antioxidant activity and to establish the mechanism of action, a SAR analysis and DFT quantum chemical computations were also performed.
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Eur. J. Med. Chem. 78 (2014) 198-206

One-Pot Synthesis and Radical Scavenging Activity of Novel Polyhydroxylated 3-Arylcoumarins
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An unexpected domino rearrangement brought about the development of a novel one-pot procedure for synthesis of coumarins. This protocol allowed the gram-scale synthesis of a variety of polyhydroxylated derivatives 3a–p, from readily available starting materials at a low cost. Based on two proven intermediates, a probable mechanism consisting of boron tribromide induced demethylation/lactone ring opening/elimination/isomerization/lactone ring closure reaction sequence of in situ formed 3-aryl-3,4-dihydroisocoumarin-4-carboxylic acids was deduced. Compared to the common methods, used for the synthesis of coumarins, the proposed herein possesses great advantages, such as mild conditions, good yields for short reaction time, simple work-up procedure and easy isolation of the final products. The structure of the newly synthesized compounds 3a–p was established by spectroscopic methods (1H NMR, 13C NMR, IR, MS and HRMS) and their radical scavenging activity was evaluated in vitro against 1,1-diphenyl-2-picrylhydrazyl free radical (DPPHradical dot). The results obtained show that compounds 3g–p posses higher radical scavenging activity (3.16 ≤ SC50 [μM] ≤ 6.82) than well-known antioxidants such as trolox, protocatechuic acid, caffeic acid and gallic acid (SC50 [μM] = 9.34, 8.83, 9.48, 5.33, respectively), which is a precondition for promising antioxidant activity of these compounds to be expected.
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Sep. Purif. Technol. 103 (2013) 279-288

Ionic liquid-supported solid–liquid extraction of bioactive alkaloids. II. Kinetics, modeling and mechanism of glaucine extraction from Glaucium flavum Cr. (Papaveraceae)
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Abstract: The temperature dependence on the global kinetics of both methanol and 1-butyl-3-methylimidazolium acesulfamate ([C4mim][Ace])-supported extraction of the bioactive alkaloid S-(+)-glaucine from plant material of Glaucium flavum Crantz (Papaveraceae) was measured and a comparative analysis in respect to the extractant type was performed. The experimental data was fitted with high coefficients of determination by means of an empirical model showing that the extraction process in both cases follows second-order kinetics. The concentration at saturation, Cs, extraction rate constants, k2, initial rates of extraction, h, and activation energies of extraction, Ea, were then calculated and discussed. The obtained results give a considerable advantage to the Ionic liquid-supported (IL-supported) extraction procedure due to the faster and quantitative glaucine transfer, regardless the temperature. A plausible extraction mechanism scenario, describing the whole system in terms of solute–solvent, solute–matrix and matrix–solvent interactions at every stage of the extraction process was proposed. As a result, the apparent kinetics and yield of the IL-supported extraction were attributed to the cell wall modification by H-bonding interactions between both ions of [C4mim][Ace] and cellulose, resulting in the plant tissues disruption. The latter was further unequivocally confirmed by means of scanning electron microscopy. The kinetics parameters obtained were then implemented into a model for the prediction of glaucine amount extracted in 1 M [C4mim][Ace] water solution at any temperature and time with good predictive ability.
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Sep. Purif. Technol. 97 (2012) 221-227

Ionic liquid-supported solid–liquid extraction of bioactive alkaloids. I. New HPLC method for quantitative determination of glaucine in Glaucium flavum Cr. (Papaveraceae)
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A series of hydrophilic 1-alkyl-3-methylimidazolium-based ionic liquids were used as extractants for the effective extraction of S-(+)-glaucine from plant material of Glaucium flavum Crantz (Papaveraceae). The extractions were carried out both under ultrasonic and conventional heating conditions and the extraction efficiency was monitored by HPLC. The influence of the anion (chloride, bromide, acesulfamate and saccharinate), alkyl chain length in the imidazolium ion, concentration, extraction time, and plant material/extractant ratio was investigated. A comparative study between conventional Soxhlet extraction with methanol as a solvent (total extraction) and water solutions of ILs shows the same extraction ability of ILs, but with significantly reduced extraction time. Moreover, the extraction efficiency was shown to be strongly anion dependent. The results obtained provide a fast and safe method for determination of glaucine in G. flavum Cr.
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Eur. J. Med. Chem. (2013) 185 – 192

A novel one-pot synthesis and preliminary biological activity evaluation of cis-restricted polyhydroxy stilbenes incorporating protocatechuic acid and cinnamic acid fragments
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A series of new stilbenes 4a–e, 5 were synthesized through a novel one-pot Perkin-like reaction between 6,7-dimethoxyhomophthalic anhydride and aromatic aldehydes, followed by treatment with BBr3. This synthesis is straightforward and allows polyhydroxylated cis-stilbenes gathering two well-known pharmacophoric fragments to be obtained in good yields and for short reaction times. The structure of the newly synthesized compounds was established by spectroscopic methods (1H NMR, 13C NMR, IR and HRMS) and the double bond configuration was unequivocally elucidated by means of gated decoupling 13C NMR spectra and 2D NOESY experiments. Preliminary differentiating screening of their radical scavenging, antibacterial, anti-fungal and tyrosinase inhibitory activity was further performed. The results obtained suggest that the tested compounds possess a triple biological action as potent radical scavengers, antifungal agents and tyrosinase inhibitors in micromolar concentration. The most promising bioactive compound amongst the others was 4a, acting as excellent radical scavenger against DPPH• radical (IC50 ≤ 10 μM), antifungal agent suppressing the growth of Fusarium graminearum (89% inhibition at 0.17 μmol/mL), and tyrosinase inhibitor showing higher activity than hydroquinone at 23 μM.