Figure 21.

Fine-tuning of quercetin (Q) and luteolin (L) (Table 2) diffusion values. 500 MHz ¹H-NMR DOSY of a mixture of luteolin (3.7 mM) and quercetin (3.5 mM) in DMSO-d₆ (289 K, Δ = 100 ms, δ_g = 4.8 ms, ns = 16, total experimental time 27 min). The insert indicates the hydroxyl protons at a lower contour level (×8 and ×16). (A) Without and (B) with the addition of 0.07 mM picric acid (molar ratio [picric acid]/[luteolin]~0.014 and [picric acid]/[quercetin] = 0.015). Reproduced with permission from [55]. Copyright 2012, by Elsevier Science Ltd. (Amsterdam, The Netherlands).