Tandem Mass Spectrometry and Nuclear Magnetic Resonance Spectroscopy Studies of Candida bombicola Sophorolipids and Product Formed on Hydrolysis by Cutinase

✍ Scribed by C.G. Dekoster; W. Heerma; H.A.M. Pepermans; A. Groenewegen; H. Peters; J. Haverkamp

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 957 KB
• Volume: 230
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.1995.1448

✦ Synopsis

Natural mixtures of sophorolipids produced by the yeast Candida bombicola have been analyzed by fast atom bombardment (FAB)-MS and collision-induced dissociation (CID)-MS. Some pure components have been analysed by two-dimensional NMR spectroscopy. The presence of acidic, lactonic, and O-acetylated forms and the position of double bonds in the fatty acid part of these glycolipids can be easily inferred from positive and negative ion FAB-mass spectra. Details about position of O-acetylation can be obtained from CID mass spectra of [M+H]+ and [M-H]- ions and from the NMR spectra. Differences in CID fragmentation between protonated and sodiated molecular ions are discussed in detail. Enzymatic hydrolysis of 6',6"-di-O-acetyl sophorolipid lactone by cutinase from Fusarium solani results specifically in the removal of the 6'-O-acetyl group, whereas the 6"-O-acetyl and lactone group are resistant. This specificity is explained from a three-dimensional model of the sophorolipid generated on the basis of the short 1H,1H distances as inferred from the NMR (ROESY) spectra.