ellipsoidea CBS 128.78.11 The spore extraction also gave rise to some lipid classes (particularly fatty acyls, sterol lipids) with polar glycerophospholipids being lost by methanol wash compared to intact spore measurements. The peak at m/z 273.0393 was a MALDI matrix dimer. In S. prolificans CBS 116904 just lipid components were detected (Table 1). These were present both on intact fungal spores and in chloroform/methanol extracts of mycelium (see experimental). The MALDI mass spectrum this website of CBS 116904 was dominated by glycero- and glycerophospholipids within 2 ppm accuracy (Fig. 1c). Interestingly, mMass did not label many abundant peaks in the mass region 700–800

Th indicating possibly missing LIPIDMAPS database entries. These

peaks were interpreted by tandem mass spectrometry as MHCs later on. Pinto et al. identified some MHCs from P. boydii as molecules containing a glucose residue attached to 9-methyl-4,8-sphingadienine in amidic linkage to 2-hydroxyoctadecanoic or 2-hydroxyhexadecanoic acids.6 In the recent study, both species have also been detected as sodiated adducts not only on spores of S. prolificans but also in P. boydii strains involved in this study. MHCs were displayed at m/z 750.5488 and 778.5801 defining the fatty acyl parts as C16:0(OH) and C18:0(OH) respectively. The production of fungal cerebrosides and their unsaturated analogues C16:1(OH) and C18:1(OH) is not scarce and was described also in other human pathogens.7,12,13 Hydroxylated Decitabine MHCs preferentially produced stable sodiated/potassiated adducts. This adduct ion formation represented another complicating factor for any lipid library search. Chemical interference arising from both sample complexity and/or cationization

could deteriorate precise mass assignment even in high resolution Fourier Transform instruments having sufficient dynamic range. In this study, exact mass and isotopic patterns were not enough and tandem mass spectrometry had to be applied for MHCs structure authentication. For this purpose, we studied the fragmentation behaviour of a standard ADAMTS5 cerebroside bearing C18:1(OH) acyl group (see experimental). Knowing the elemental composition of the fragments generated by the collision-induced dissociation of the [M + Na]+ ions (m/z 776) enabled us to assign per analogiam the structures of its C16:0(OH) and C18:0(OH) analogues found in fungal extracts (Table 2). In addition to trivial eliminations of water (−18 Da), hexose (−162 Da) and hexose + water (−180 Da) moieties from the sodiated molecule, three important fragment ion series defined positions in which potential structural changes could take place. Hexose-containing ions were represented by fragment ions A, B and C and their corresponding dehydrated analogues (Fig. 3). 2-Hydroxyoctadecanoic or 2-hydroxyhexadecanoic acid-bearing ions were A and [MNa-Hex]+. On the contrary, 9-methyl-4,8-sphingadienine-related ions were B, C, [MNa-Hex]+ and their dehydrated analogues.