О химическом составе сухих экстрактов листьевGymnema sylvestre

Three certified medicinal preparations ofGymnema sylvestre dry extracts have been studied in gravimetric percentage concentrations of 25, 50, and 75%. After the extraction with water - alcohol solution, supernatants of all preparations were analyzed for the presence of phenolic and amino acids using TLC in the ascending mode. A considerable amount of various organic compounds, including plant phenols, was detected in the samples. The presence of these phenols was confirmed by the characteristic reaction with iron(III) chloride and the Pauli's diazo reaction. A small amount of amino acids was detected in extracts by means of ninhydrin reaction; their maximum content (0.15 mole/kg) was found in 50% preparation. Along with this, a special feature of the amino acid composition ofGymnema sylvestre is the complete absence of proline. According to the drug certificate, molar concentration of gymnemic acids in medical preparations is 0.12 mole/kg, which is comparable with the content of phenolic and amino acids determined in the course of experiments. Thus, in purifyingGymnema sylvestre dry extracts, one should pay attention to the possible reduction of the content of these components.