19 - Pelargonium graveolens

Abstract

Pelargonium graveolens L’Hér. (Geraniaceae), also known as ‘rose-scented geranium’, is a shrub with hairy stems and velvety leaves that grows to a height of 1.3 m. The plant occurs in South Africa, Zimbabwe and Mozambique. The plant is well-known for its essential oil (geranium oil), which is used in the fragrance, flavour and aromatherapy industries. The healing properties of P. graveolens extend to the extracts, which are used to treat diarrhoea, dysentery, nausea, colic, stomach cramps, kidney and bladder ailments. The oil has been used since ancient times by the Egyptians to suppress cancerous tumours. In vitro (antimicrobial, anti-inflammatory, anti-oxidant) and in vivo (antidiabetic, anti-oxidant) properties of the plant have been demonstrated. A quality control protocol was developed for P. graveolens, based on the chromatographic profiling of the volatile fractions (essential oil) using semi-automated high-performance thin-layer chromatography (HPTLC) and gas chromatography coupled to mass spectrometry and flame ionisation detection (GC-MS-FID). Six commercial essential oils were obtained from South Africa and analysed using HPTLC and GC-MS-FID. The HPTLC profiles of the essential oils showed the presence of linalool and geraniol under white light, following derivatisation with anisaldehyde reagent. The GC-MS-FID profiles confirmed the presence of the marker compounds geraniol, isomenthone, citronellol, linalool, citronellyl formate, geranyl formate and guaia-6,9-diene in the oils.