Figure 2.

150 MHz solid-state ¹³C magic-angle spinning (MAS NMR) spectra showing carbon-containing chemical moieties in C. neoformans melanized cell walls produced with different catecholamine precursors. Left, a–d: quantitatively reliable DPMAS NMR yields C = C/CHO and (CH₂)_n/CHO peak ratios for ¹³C-enriched membrane lipids and polysaccharides in melanin ghosts produced using d-[U-¹³C₆]glucose and natural-abundance (1.1% ¹³C) catecholamine precursors. Peak assignments are based on published reports for fungal cell walls and mammalian phospholipids (10, 32), with C = C and (CH₂)_n groups that originate primarily from the membrane-derived functional groups marked in green. Right, e–h: comparative X-band EPR and cross-polarization (CPMAS) NMR spectra of melanins produced from natural-abundance glucose and catecholamine precursors. Each NMR spectrum is presented with the tallest peak set at full scale.