Grevillosides J–Q, Arbutin Derivatives from the Leaves of <i>Grevillea robusta</i> and Their Melanogenesis Inhibitory Activity

Abstract

From the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Grevillea robusta, new arbutin derivatives and related compounds, named grevillosides J-Q (1-8), together with eight known compounds (9-18) were isolated. Various kind of acyl groups were attached to β-D-glucose at the 6-position through an ester linkage. Their structures were mainly elucidated from one-and two-dimensional NMR spectroscopic data. For exploitation as skin-lightening and anti-chloasma agents, the inhibitory activities of the isolated compounds as well as ones isolated in previous experiments (19-31) toward tyrosinase and melanin-producing B16 cells were assayed. Several compounds showed promising activity.

Inhibitory mechanism of two homoisoflavonoids from Ophiopogon japonicus on tyrosinase activity: insight from spectroscopic analysis and molecular docking

“…Currently, kojic acid, 8 hydroquinone, 9 grevillosides 10 and steroids 11 are recognized as Tyr inhibitors, but of these inhibitors some are ineffective at low concentrations and unsafe at high concentrations, which can cause some significant side effects, including dermatitis, skin allergy, macular brown and skin cancer. 12 Although kojic acid is very effective even at lower concentration, it is a chemically synthesized drug with poor stability and may cause cancer in long-term use.…”

Distinctive Arbutin‐Containing Markers: Chemotaxonomic Significance and Insights into the Evolution of Proteaceae Phytochemistry

“…Taken together, the biosynthetic connections within the classes of unusual arbutin ester moieties that we have identified from relictual Proteaceae and more successful taxa from this family are consistent with the chemotaxonomic significance of these unusual molecules (Figure 5). [9,20h,21b,22,24,28–30,31] Specifically, we note that arbutin derivatives containing phenylalanine‐derived esters (blue fragments) have only been identified in Bellendena , Persoonia , Cenarrhenes , Protea , Agastachys , Helicia , Orites , Helicopsis , Grevillea , and Hakea genera to date (Figure 5). All genera are found in the family Proteaceae and these members span the phylogeny, including relictual and more successful members.…”

“…Benzoyl acetate or oxidized coumaroyl substituents (e. g., blue fragments within arbutin esters 1 c , 1 d , 1 i – 1 k , and 4 a – 4 d ) likely derive from the biosynthesis of phenylalanine [26] . Robustaside E ( 4 a ) was isolated from Grevillea ‘ Poorinda Queen’, [22] grevillosides L and M ( 4 b and 4 c ) were obtained from Grevillea robusta , [21b] and compound 4 d was found in Protea neriifolia [20h] . All of these are plant species are from the family Proteaceae.…”

Isolation of Three New Diterpenes from <i>Dodonaea viscosa</i>

“…34) In the present study, we evaluated the collagenase inhibitory activity, as well as the tyrosinase (an enzyme that catalyzes the production of melanin and other pigments) inhibitory activity, of all the isolated compounds. 35,36) As shown in Table 2, compound 9 showed the most potent collagenase inhibitory activity, while compound 11 showed almost the same activity as the positive control (caffeic acid). Compounds 8 and 12 showed moderate tyrosinase inhibitory activities with inhibition percent values of 34.6 and 48.8%, recpectively, the inhibitory activity of a positive control, arbutin, being 32.1%.…”