Coloured compounds were isolated and characterised from the products of the reaction between aqueous xylose (1 m) and glycine (1 m), refluxed for 2h, initial pH, 6. The products were separated by extraction with light petroleum (boiling point, 60–80°C) followed by ethyl ether. The brown ether-solubles were fractionated by TLC using two systems and semi-preparative reversed phase HPLC in sequence. The twenty-two main peaks were collected and freed from adjacent peaks and shoulders by further HPLC before mass spectrometry. The seventeen compounds which gave orange or yellow solutions in methanol were of the following molecular weights: 149, 165, 178, 191, 192(a), 192(b), 192(c), 222(a), 222(b), 279, 281, 319, 364, 368, 385(a), 385(b) and 448 daltons. The compound of 319 daltons (B319) was characterised by pmr, electronic absorption spectroscopy and MS (low and high resolution). A structure is proposed for it. For the six coloured compounds over 300 daltons there is evidence for the presence of 3 and 4 linked heterocyclic rings. These may arise from reactions of 2-furfurylidene-4-hydroxy-5-methyl-3(2H)-furanone or a nitrogen-bearing analogue. Structures for some fragments have been proposed, the high resolution MS data for B319 helping indirectly, where compounds, for which only low resolution data were available, exhibited common ions.