Involved in the biosynthesis of Glycyrrhetinic acid (GA), a natural product which exhibits anti-inflammatory activity (PubMed:31138208). Involved in the biosynthesis of the triterpenoid saponin glycyrrhizin (PubMed:22128119). Catalyzes three sequential oxidation steps at C-30 of 11-oxo-beta-amyrin (PubMed:22128119). Also able to catalyze C-30 monohydroxylation of beta-amyrin to produce 30-hydroxy-beta-amyrin (PubMed:22128119). May be also responsible for the oxidation at positions C-22 and C-29 in addition to C-30 (PubMed:22128119). 11-oxo-beta-amyrin + 3 O2 + 3 reduced [NADPH--hemoprotein reductase] = glycyrrhetinate + 4 H(+) + 4 H2O + 3 oxidized [NADPH--hemoprotein reductase] 11-oxo-beta-amyrin + O2 + reduced [NADPH--hemoprotein reductase] = 30-hydroxy-11-oxo-beta-amyrin + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 30-hydroxy-11-oxo-beta-amyrin + O2 + reduced [NADPH--hemoprotein reductase] = glycyrrhetaldehyde + H(+) + 2 H2O + oxidized [NADPH--hemoprotein reductase] glycyrrhetaldehyde + O2 + reduced [NADPH--hemoprotein reductase] = glycyrrhetinate + 2 H(+) + H2O + oxidized [NADPH--hemoprotein reductase] Expressed in roots, stolons and stems. Not detected in leaves. Saccharomyces cerevisiae expressing Glycyrrhiza uralensis CYP88D6 and CYP72A154, combined with the expression of Arabidopsis thaliana beta-amyrin synthase (beta-AS) and NADPH-cytochrome P450 reductase, accumulates glycyrrhetinic acid (GA) and, to lower levels, beta-amyrin; these GA production was increased in the presence of G.uralensis cytochrome b5 (GuCYB5). Belongs to the cytochrome P450 family.