Fatty Acids, Triacylglycerols, and Sterols in Neem Oil (Azadirachta Indica A. Juss) as Determined by a Combination of Chromatographic and Spectral Techniques

Abstract

Quantitative thin‐layer chromatography in silver ion and reversed phase modes, gas chromatography, gas chromatography–mass spectrometry, and ¹³C nuclear magnetic resonance spectrometry were employed to determine the lipid composition in neem (Azadirachta indica A. Juss) kernel oil. Thirteen fatty acids and 25 triacylglycerols species were identified and quantified. The seven main triacylglycerols species were found in almost equal amounts in the range 7–10%. Saturated fatty moieties occupied positions 1‐ and 3‐ in the triacylglycerol molecule, oleic acid was almost equally distributed, and linoleic acid predominantly occupied position 2. Sitosterol, stigmasterol, campesterol, and fucosterol were the main components in free sterol and sterol ester fractions.

Keywords:

• Gas chromatography
• Thin‐layer Chromatography
• NMR
• Fatty acids
• Triacylglycerols
• Neem oil

Acknowledgments

We thank Mrs. Velikova for the skillful technical assistance. Thanks are due to Dr. S. Simova for performing the NMR analysis and the helpful discussion. Financial support from the Bulgarian National Science Fund, contract #X‐1513 and the Brazilian government agency (FAPEMIG) is gratefully acknowledged. Scholarship (GNJ) from Brazilian government agency (CNPq) is also acknowledged.