1. Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
2. Technological Faculty, Department of Technology of Tobacco, Sugar, Vegetable and Essential Oils, University of Food Technologies, Plovdiv, Bulgaria
3. Department of Heat Engineering, Technical Faculty, University of Food Technologies, Plovdiv, Bulgaria
4. Technological Faculty, Department of Organic Chemistry and Inorganic Chemistry, University of Food Technologies, Plovdiv, Bulgaria