Figure 1.
Verbascoside (Acteoside) is a PPG with applications in food and pharmaceutical sciences.
The PPG molecule contains one or more sugar molecules and two antioxidants linked through an ester and glycosydic linkages.
Figure 2.
Enzymatic synthesis of galactosides 3 and 4 catalyzed by β-galactosidase from Kluyveromyces lactis.
Acceptor substrates (250 mM), lactose (donor; 1 M) and MgCl2 (0.01 M) were suspended in phosphate buffer (50 mM and pH 6.5) and incubated at 35°C prior to an addition of 12 U/mL β-galactosidase.
Figure 3.
Lipase-catalyzed acylation of galactosides.
30 mM of aromatic galactosides were reacted with an equivalent amount of donor substrates with Novozym 435 (20 mg/mL) and 100 mg/mL of molecular sieves (5Å, 8–12 mesh) in 2-methyl-2-propanol. The enzymatic reaction was carried out for 24 h at 75°C with constant stirring.
Table 1.
DPPH• antioxidant activity of compounds 1–13 and ascorbic acid as a positive control.
Figure 4.
Full electron donator acceptor map (FEDAM).
Dashed lines are only included to aid visualization. Adapted from reference 48 b.
Figure 5.
Structural representation of compounds from Table 1 and their deprotonated species are shown.
When known, the experimental pKa values are also included.
Figure 6.
Dashed lines are only included to aid visualization. Molecules located below the dashed line are better electron donors when compared to DPPH•. Triangles represent compound 3, circles represent compound 10 and squares represent values of the deprotonated compounds of 5, 6, 7 and 8. β-carotene (BC) and astaxanthin (ASTA) are included for comparison.
Figure 7.
Experimental pKa and IC50 values are shown.
Dashed lines are only included to aid visualization.
Table 2.
Adiabatic Gibbs free energy in water (kJ/mol) at 298.15 K for reactions between the radical scavengers ((anti−H) −1 and (anti−2H) −2) and the DPPH• are shown.