Fig. 2: Nuclear magnetic resonance spectroscopy of A0106.

1H NMR spectrum (800 MHz, CD3OD) of mHDOM extract 4A0106, with 1H NMR section integrals of main substructures (cf. Table S3). Apart from certain sharp NMR resonances which possibly denote individual aliphatic CHO molecules, mHDOM comprised relevant background of broad bulk 1H NMR resonances that represent a huge diversity of aliphatic branched alkyl and remotely oxygenated aliphatic groups (δH ~ 0.6-2.7 ppm) and aliphatic OCH molecules (δH ~ 3.2-4.2 ppm); the overall curvature suggests higher relative abundance of aliphatic alcohols and ethers (δH < 3.8 ppm) in comparison with e.g. aliphatic esters (δH > 3.8 ppm). Ammonium (14NH4+) showed a distinct 1:1:1 triplet at δH ~ 4.5 ppm with 1JNH = 42.7 Hz (1.2% of 1H NMR integral; Fig. S8a–c).