Isoliquiritoside

Excli Journal, 2014, 13:897-921.

Inhibitors of pancreatic lipase: state of the art and clinical perspectives.[Pubmed: 26417311]

Luteolin-6-C-β-D-boivinopyranoside (24), orientin (25), isoorientin (26), derhamnosylmaysin (27) and isoorientin-2-O-α-L-rhamnoside (28) from the methanolic extract of the leaves of Eremochloa ophiuroides (centipede grass), has reported to inhibit the pancreatic lipase with IC50 of 50.5 ± 3.9, 31.6 ± 2.7, 44.6 ± 1.3, 25.9 ± 3.7 and 18.5 ± 2.6 μM respectively (Lee et al., 2010[38]). Licuroside (29) and Isoliquiritoside (30) from Glycyrrhiza glabra roots showed strong inhibition against pancreatic lipase with IC50 of 14.9 and 37.6 μM respectively (Birari et al., 2011[3]) (Figure 5(Fig. 5)).

Computers & Applied Chemistry, 2012,29(6):656-660.

Density functional theory calculations on antioxidation activity of four flavones from radix glycyrrhizae.[Reference: WebLink]

METHODS AND RESULTS:
The geometrical structures of the four main compounds of glycyrrhiza flavonoids,liquiritigenin,liquiritin,isoliquiritigenin and Isoliquiritoside,which have potential medicinal value of antioxidant activity,remarkable anti-tumor and anti-HIV effects,have been calculated by using the Density Functional Theory(DFT) B3LYP method with 6-311G(d,p) basis set. The properties of the glycyrrhiza flavonoids have been discussed in detail based on their molecular structures,NBO charges on hydrogen atoms,the dissociation energy of O-H bonds,the energies of the highest occupied molecular orbital(HOMO) and the lowest unoccupied molecular orbital(LUMO),the energy gap between HOMO and LUMO,and etc.The results showed that C_7-OH is likely the most active site to eliminate free radicals in human body by dehydrogenation,while the 4'-OH also is probably an active site to enhance the antioxidant activity of the molecules.Smaller 7-OH bond dissociation energy of hydroxyl,bigger positive charge value on hydrogen atom,relatively higher the HOMO energy,and smaller ΔE_(LUMO-HOMO) are contributive to improve the antioxidant activity of the flavonoids.Isoliquiritigenin and Isoliquiritoside are completely planar due to the presence of the double bond between C_2 and C_3,which can increase the molecular itself antioxidant activity due to the larger conjugate π molecular orbital.The glucoside substitute for the hydrogen of 4'-OH can slightly increase the energy level of the HOMO and LUMO,but,at the same time,the losing 4'-OH decreases the total molecular antioxidant activity since lost one active site.
CONCLUSIONS:
As a result,it was revealed that the antioxidant activity of the compounds goes along with the series Isoliquiritigenin ≧ Isoliquiritoside Liquiritigenin ≧liquiritin.