Carbon nuclear magnetic resonance spectroscopy (13C-NMR)
In 13C-NMR spectrum of sophorolipids produced by Starmellela bombicola, peak at 20.7 were assigned as the ω-end carbon (C-18) and the one at 77.4 ppm were assigned as ω-1 carbon (C-17) of fatty acid respectively. While the peak at 69.7 ppm in the 13C-NMR spectrum of sophorolipids produced by Candida batistae was assigned as the ω-end carbon (C-18) [18]. In the structure elucidation of mannosylerythritol lipid from Candida sp. SY16, peaks at 23.7-33.1 ppm were assigned as
–CH2- groups in fatty acids and peaks at 128.8, 129.7, 130.2 and 131.1 ppm were assigned as four =CH- groups in unsaturated fatty acids