At the beginning of the 20th century the Bulgarian medical doctor Dr. Stamen Grigorov, who had been a student at that time in Geneva, discovered a special kind of Lactobacilli in samples of Bulgarian Yoghurt and called them Lactobacillus Bulgaricus.

Later on the well-known Russian scientist Illya Metchnikoff – one of the founders of modern immunology, discovered the beneficial qualities of Lactobacillus Bulgaricus. According to him the beneficial effect of Bulgarian ‘sour milk’ (Yoghurt) was due to the lactic acid produced by the Lactobacilli. In his classical papers he linked the longevity of the Bulgarian people with the consumption of yogurt and stressed on the fact that this had been the only bacterium that had never damaged the human organism anyhow. Metchnikoff was the first scientist that had created a healing preparation on the basis of Lactobacillus Bulgaricus, called ‘Lactobacillin’.

In 1951 Dr. Ivan BOGDANOV isolated from Bulgarian Yoghurt a special strain Lactobacillus Bulgaricus – “I. Bogdanov patent strain tumoronecroticance B-51” – ATCC 21815, LB51® in short.

At the beginning, parallel to the searching of optimal conditions for cultivating and maintaining of the isolated strain a very important purpose had been the isolation and the purification of an antibiotic substance discovered by Dr. Ivan Bogdanov. Apart from the lactic acid synthesized by the strain it was also a very potent producer of an antibiotic substance with wide range of antibacterial activity, which was applied later in the preparation NORMOFLOR®

In 1956 Dr. Ivan Bogdanov discovered that the strain “LB51®” exerted a pronounced anti cancer activity, quite different from that of the cytostatics and chemotherapeuticals used at that time.

The initial clinical experiments were carried out by Prof. P. Pophristov and Dr. Ivan Bogdanov using crude extracts from “LB51®” applied by ‘intra tumor’ injections in cases with spino- and baso-cellular carcinoma.

As a result of the chemical purification of the ‘tumor necrotizing substance’ of “LB51®” in 1966 Dr. Ivan Bogdanov elaborated a preparation provisionally called Blastolysin [now called DEODAN (for i.v.) used as a standard test substance], and determined as glycopeptide from the cell wall of Lactobacillus Bulgaricus “LB51®.

In 1967 Dr. Ivan Bogdanov started applying the oral preparation. Initially the preparation carried the name of “Antibioticum Bulgaricum – AB“, then it was named not quite successfully ANABOL and now we have registered a trade mark – DEODAN® – a high molecular-weight substance, containing muramyl-peptides.