A chemotaxonomic study on the resins of Shorea macrophylla, Shorea pinanga, and Shorea hopeifolia was conducted. The dichloromethane extracts were separated into neutral and acidic fractions and then analyzed using GC-MS. The neutral fraction analysis revealed that spathulenol, caryophyllene oxide, aromadendrene oxide, and isoaromadendrene epoxide were the major constituents in all three species. Furthermore, the main compound in the neutral fraction of Shorea hopeifolia was isocaryophyllene which was undetected in the other two species. The major constituent of the acidic fraction of the three species was hexadecanoic acid, while pentadecanoic acid was the major constituent in the acidic fraction of Shorea pinanga and Shorea hopeifolia. Therefore, the presence of sesquiterpenes as well as fatty acids in S. macrophylla, S. pinanga, and S. hopeifolia was discovered to be a marker for identifying the genus Shorea.
This study investigated the antioxidant activity from the methanol (MeOH) soluble extract of the inner and outer bark of Swietenia macrophylla. The MeOH soluble extracts were fractionated into ethyl acetate (EtOAc) soluble and insoluble. The antioxidant activity was conducted by DPPH (1,1-diphenyl-2-picrylhydrazyl) method and the phenolic compounds were detected by GC-MS. The levels of total phenolic content of soluble and insoluble fraction of EtOAc of outer bark were higher than in inner bark, while total flavonoid content showed opposite results. The crude methanol extract and its EtOAc soluble fraction of outer bark showed a higher level of antioxidant activity. The GC-MS analysis detected higher levels of fatty acids and alcohols of 87.12% than phenolic compounds of 12.17% in the inner bark, while the outer bark showed the opposite pattern with phenolic compounds of 82.65% than fatty acids of 8.43%. A strong correlation was demonstrated between total phenolic content and antioxidant activity.