Fig. 2.

Yield of formaldehyde in different concentrations ofd-ribose in Tris−HCl buffer. Different concentrations of d-ribose (10, 50, 100 and 500 mM) were incubated in 20 mM Tris−HCl buffer (pH = 8.0) for 3 days. Aliquots were taken for the measurement of formaldehyde with DNPH by HPLC (a–d). d-glucose solution and Tris−HCl buffer were also measured. All of the values are expressed as the means ± S.E.M. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001, n = 3.