Chapter 2 - Agathosma betulina

Abstract

Agathosma betulina (P.J. Bergius) Pillans (Rutaceae), commonly referred to as ‘buchu’, is an evergreen, fragrant shrub that grows up to 2m in height and is naturally distributed in the Western Cape Province of South Africa. The leaves are aromatic and, upon distillation, produce a golden oil, with a strong-sweetish, peppermint-like scent. Buchu oil is a flavour enhancer in foods and beverages, and a fragrance material in perfumes. Traditionally, the plant is used to treat cholera, indigestion, constipation, prostatitis, rheumatism, fever, respiratory and urinary tract infections, as well as for disinfecting wounds and relieving menstrual cramps. Agathosma betulina is commercially marketed as fresh or dried leaves, tinctures, herbal water and essential oils. This monograph is a record of the ethnobotany, phytochemistry, in vitro and in vivo biological properties of the plant, as well as its toxicity profile. Furthermore, chemical profiling was performed using semi-automated high-performance thin-layer chromatography (HPTLC), ultra-performance liquid chromatography coupled to mass spectrometry (UPLC–MS), gas chromatography coupled to mass spectrometry (GC–MS) and flame ionisation detection. Isomenthone, diosphenol, limonene, menthone, pulegone, pseudo-diosphenol, 8-mercapto-p-menthan-3-one, 8-acetylthio-p-menthan-3-one, 8-methylthio-p-menthan-3-one, 4-hydroxydiosphenol and 1-hydroxydiosphenol were the predominant compounds in the essential oil, as determined by GC–MS analysis. The marker compounds in the non-volatile fraction were identified as diosmin, hesperidin and rutin, based on both HPTLC and UPLC–MS analysis.