n-alkanes in epicuticular waxes of Vigna unguiculata (L.) Walp. leaves

Abstract The n-hexane extracts of young, mature and senescent leaves from Vigna unguiculata (L.) Walp., commonly known as cowpea, containing a thin layer of epicuticular waxes were analysed by thin-layer chromatography, gas chromatography and gas chromatography-mass spectrometry. Samples (100 g) of young, mature and senescent leaves indicated the presence of 14, 15 and 14 long-chain n-alkanes, accounting for 6380 ± 77.2, 8774 ± 70.1 and 5686 ± 76.0 μg (mean ± SE), respectively. The predominant n-alkane was hentriacontane (n-C31) in all three types of leaves, representing 1490 ± 20.3, 1543 ± 17 and 902 ± 9 μg in young, mature and senescent leaves, respectively, while pentacosane (n-C25), pentatriacontane (n-C35) and n-C25 were present in the lowest amounts in young, mature and senescent leaves, accounting for 33 ± 0.3, 34 ± 1.2 and 56 ± 0.7 μg, respectively.