1 - Adansonia digitata

Abstract

Adansonia digitata L. (Malvaceae), commonly known as ‘baobab’, is a large tree used in Africa for its medicinal and nutritional value. In many African countries, different plant parts are used to treat malaria, diarrhoea, fever, inflammation, kidney and bladder diseases. Baobab is a rich source of vitamin C, yielding levels of ascorbic acid rivalling many commercial fruits. Various in vitro and in vivo biological activities of various parts of the plant have been investigated, and results showed promising anti-oxidant, anti-inflammatory and antiviral properties. Here, we propose a quality control protocol for A. digitata based on chromatographic profiling of the non-volatile fraction from the fruit pulp and seed oil constituents. Using a semi-automated high-performance thin-layer chromatography (HPTLC) system, ultra-performance liquid chromatography coupled to mass spectrometry and photodiode array detection (UPLC-MS-PDA), and gas chromatography coupled to mass spectrometry and a flame ionisation detection (GC-MS-FID), the chemical profiles of six specimens of A. digitata were established. The fruit pulp was obtained commercially and extracted with methanol. The seed oils (commercial samples) were obtained by the cold pressing method and the fatty acid methyl esters (FAMEs) obtained by esterification. The non-volatile fractions were analysed using HPTLC and UPLC-MS-PDA, while the FAMEs were profiled using HPTLC and GC-MS-FID. Various compounds, including procyanidin dimer I, epicatechin, procyanidin dimer II, kaempferol glycoside I and kaempferol glycoside II, were identified in the fruit pulp using UPLC-MS-PDA, while HPTLC confirmed the presence of ascorbic acid, catechin and epicatechin in the fruit pulp. Analysis of the seed oil by GC-MS revealed the presence of four major FAMEs, namely palmitic acid, stearic acid, linoleic acid and oleic acid methyl esters.