Fig. 7

Heteronuclear NMR spectra acquired on biosurfactants dissolved in D₂O. (a) ¹ H-¹³ C HSQC spectrum of the crude extracts of biosurfactants. The insets show a zoom of the spectrum of the biosurfactants (black) superimposed with the ¹ H-¹³ C HSQC spectrum of trehalose deposited in the BMRB (red). (b) Superimposition of a region of the ¹ H-¹³ C HMBC spectra of biosurfactants (black) and of trehalose deposited in the BMRB. (c, d) Zoom of the carbonyl region of the ¹ H-¹³ C HMBC spectra of crude biosurfactants (c), and after basic hydrolysis (d). All the spectra were recorded at 25 °C