Comparative analysis of the essential oil composition of Murraya paniculata and M. exotica

Murrayae Folium et Cacumen (MFC) is a traditional Chinese medicine (TCM) derived from the leaves and twigs of two aromatic species of Rutaceae: Murraya paniculata (L.) Jack and M. exotica L. It has long been used as a folk medicine in South China for the treatment of a variety of disorders, particularly for inflammatory lesions and pains. In the present study, a detailed chemical examination as well as a comparative analysis of the essential oil composition of M. paniculata and M. exotica was conducted by gas chromatography-mass spectrometry (GC-MS). A total of 141 volatile components were identified from the essential oil of these two plants. Sesquiterpenes were found to be the predominant constituents, accounting for 92.8% of the oil from M. paniculata and 87.9% of that from M. exotica. A comparative analysis of the essential oil composition of these two plants revealed a high level of similarity in their main constituents, such as the co-occurrence of E-caryophyllene, spathulenol and delta-elemene, which gave the chemical evidence for their equal medicinal application as MFC in TCMs. Moreover, in combination with literature reports, E-caryophyllene was theoretically deduced as one of the pharmacologically effective components of MFC that is responsible for treating inflammatory lesions and for local anaesthesia.