A Móra Ferenc Múzeum Évkönyve, 1968. (Szeged, 1968)

Gallé, László: The xerothermic lichen species cladonia magyarica VAIN

Investigation of the antibiotic activity of Cladonia magyarica

2 The air-dried lichen body was finely ground and extracted (1 g/l,\ ml n-out-anol, ethylether and chloroform at 20° С for 12 hours. The extract solvent in each case) with distilled water at 4° С and 20° C, acetone, ethanol, were filtered and the antibiotic activity was controlled by agar-diffusion cuptest. The culture medium was a bouillon of 3% agar content, supplemented with l°/o saccharose, set partly for pH 6,5, partly pH 7,5. The media were inoculated with the suspension of test microorganismus, then cups were punched out and 0,1 ml solutions were introduced into each cup of 8 mm in diameter and 3 mm in height. As test-microorganisms the following bacteria and fungi were used: Bacillus cereus var. mycoides, Staphylococcus aureus WALKER, Escherichia coli 0 111, Serratia marcescens, Candida albicans, Hansenula anomala, Aspergillus niger, Syncepahalastrum racemosum. According to the results, Cladonia magyarica contains antimicrobial agents inhibiting selectively the multiplication of the two Gram-positive bacteria. The results are summarized in the Table. The figures in the Table show the radius of the zones of inhibition, the sign „ + " marks partial inhibition and the sign „-" means inactivity. ACTIVITY OF THE EXTRACTS OF CLADONIA MAGYARICA VAIN. AGAINST GRAM-POSITIVE BACTERIA: Distilled water of EthylNChloro4° С 20° С ether Aceiunc butanol form PH 6,5 7,5 6,5 + 7,5 + 6,5 6 7,5 4 6,5 6 7,5 4 6,5 7 7,5 6 6,5 6 7,5 3 6,5 4 7,5 Bacillus cereus var. mycoides — — 6,5 + 7,5 + 6,5 6 7,5 4 6,5 6 7,5 4 6,5 7 7,5 6 6,5 6 7,5 3 6,5 4 2 Staphylococcus aureus WALKER j — — 4 2 3 + 4 2 3 + 3 + The active substances are well extractable in organic solvents applied. The antibacterial compounds were separated by thin-layer chromatography. The dried lichen material was extracted with ten-fold quantity of ethanol (w/v) under reflux for half an hour. Silica gel 6 (nach STAHL, MERCK) was used in an amount of 10 mg/cm

2 as adsorbent, and a benzenethanol (10:1) mixture as solvent system. From the extract, 0,1 ml was applied to the origin. The running distance was 12 cm. The chromatograms were developed biologically by covering the dried plates with bouillon agar of pH 7, then inoculated with Bacillus cereus var. mycoides, incubated in wet chamber at 30° С for 20 hours and checked for zones of inhibition. With this method two active compounds could be detected: very possibly atranorin (C

18

H

18

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) (Rf = 0,8) and protocetraric acid (C

62

H

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35

) (Rf — 0,53). 2 By Lajos FERENCZY 248