Essential oil composition of a medicinally important Cape species: Pentzia punctata (Asteraceae)

ABSTRACT Pentzia punctata Harv. (Asteraceae) is one of 27 species occurring in southern and North Africa. It is a Cape species that is used in traditional medicine to treat stomach ailments and respiratory complaints. Pentzia punctata is locally known in the Cape as bergwildeals and is considered to be a more potent medicine than the well-known wildeals (Artemisia afra). An infusion of the leaves can be taken to treat colds. The leaf surfaces of this species are furnished with secretory glands that are probably the site of oil accumulation. The essential oils were hydrodistilled and analysed by Gas Chromatography–Mass Spectrometry (GC/MS) and Flame-Ionisation Detectors (GC/FID) for the first time. High yields of oil were obtained – 0.85–2.45% dry wt. The oils are dominated by monoterpenes, oxygenated monoterpenes and sesquiterpenes. Camphor is a major component present, along with chamazulene which is responsible for the royal blue colour of the essential oil. Other azulene derivatives are also present. Of interest was the presence of five major compounds: camphor (up to 27.3%), chamazulene (up to 19.8%), sabinene (up to 10.8%), spathulenol (up to 11.8%) and yomogi alcohol (to 22.6%).