Chemical analysis Chemical analysis of the petroleum ether extract of
The isolated SLx-2119 was identified according to the melting point (191–194 °C m.p.), infrared spectrum (IR), nuclear magnetic resonance (1H NMR) of the proton and mass spectrometry (MS). The infrared spectrum recorded in the presence of potassium bromide was as follows: IR (KBr): √max 3292 and 1035 cm−1 (OH group) and 2945, 2850, 1460 and 1385 cm−1 (aliphatic methylene and methyl group). 1H NMR methyl single at 0.98, 0.79, 0.92, 0.96, 1.12, 0.82, and 0.86 and olefinic proton resonating at δ 5.17 (1H, t, J = 4 Hz, H-12). MS: m/z (rel int %) 218 (100), 203, 207, and 189 (pentacyclic triterpene amyrin) as described by Krishnaswamy (1999). The molecular formula indicates that it is a pentacyclic triterpene with molecular formula C30H50O, and this is supported by the characteristic play of colors given by the compound on treatment with the Liebermann–Burchard reagent (acetic anhydride–sulfuric acid). This compound can be identified as β-amyrin and the chemical structure is given in Fig. 1.