Effect of the mechanochemical activation for the extraction of diterpenes from the brown coal

Abstract The paper presents the influence of mechanochemical activation of the Slovak brown coal to make the organic structure of coal accessible for the extraction agent. It was proved that mechanical activation of optimally ground coal sample (20 min) produced ultra-fine and nano-particles with specific surface of 3.79 m 2 /g. The distribution density curves show two maxima at 6.5 μm and 42 nm, respectively. The identification of 16β(H)-kaurane in the coal extract was performed after the low-temperature supercritical fluid extraction of the coal powders with and without modifier. GC–MS chromatograms present the favourable effect of the modifier. It is well known, that the kaurane derivatives display biological activity.