alpha-Arbutin

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Not to be confused with the structurally similar stereoisomer beta-arbutin.
α-Arbutin
Names
IUPAC name
4-Hydroxyphenyl-α-d-glucopyranoside
Systematic IUPAC name
(2R,3S,4S,5R,6R)-2-(hydroxymethyl)-6-(4-hydroxyphenoxy)oxane-3,4,5-triol
Other names
  • α-arbutin
  • Hydroquinone-O-α-d-glucopyranoside
  • 4-Hydroxyphenyl α-d-gluco-hexopyranoside
Identifiers
3D model (JSmol)
89675
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.103.679 Edit this at Wikidata
EC Number
  • 440-470-8/617-561-8
KEGG
UNII
  • InChI=1S/C12H16O7/c13-5-8-9(15)10(16)11(17)12(19-8)18-7-3-1-6(14)2-4-7/h1-4,8-17H,5H2/t8-,9-,10+,11-,12+/m1/s1 checkY
    Key: BJRNKVDFDLYUGJ-ZIQFBCGOSA-N checkY
  • C1=CC(=CC=C1O)O[C@@H]2[C@@H]([C@H]([C@@H]([C@H](O2)CO)O)O)O
Properties[1]
C12H16O7
Molar mass 272.25
Melting point 201 °C (394 °F; 474 K)
Boiling point 285 °C (545 °F; 558 K) at 102.17 kPa
151 g/L
log P 2.05×10−2
UV-vis (λmax) 280 nm
Pharmacology
D11 (WHO)
Topically
Pharmacokinetics:
0.53% percutaneous absorption[1]
Legal status
  • US: Not FDA approved
  • EU: Unscheduled
Hazards
Occupational safety and health (OHS/OSH):
Ingestion hazards
 Harmful
Eye hazards
 Mild irritant
Skin hazards
 Non-irritant
GHS labelling:
GHS07: Exclamation mark
Warning
H302
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 0: Exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. E.g. sodium chlorideFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
0
1
0
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

alpha-Arbutin, or α-arbutin, is a glycosylated hydroquinone, and an anomer of the naturally occurring arbutin. α-Arbutin is used in the cosmetic and pharmaceutical industries for its skin lightening effects, treatment of hyperpigmentation, and as a safer alternative to hydroquinone.

Properties and synthesis[edit]

α-Arbutin is a synthetic substance that can be produced by enzymatic glycosylation of hydroquinone in the presence of α-amylase and dextrin. In one example, this has been done in recombinant Escherichia coli, using amylase of Bacillus subtilis and sucrose phosphorylase of Leuconostoc mesenteroides.[2]

Structurally it is the α-anomer of arbutin (β-arbutin), and like the β-form it is an enzyme inhibitor of human tyrosinase.[1]

Uses[edit]

α-Arbutin is used in the cosmetic and pharmaceutical industries for its skin lightening effects, treatment of hyperpigmentation, and as a possibly safer alternative to hydroquinone. It may also possess antioxidant properties, which can protect the skin from free radical damage.[3]

It is used in products aimed at fading solar lentigo, freckles, melasma, and other forms of hyperpigmentation where excess melanin is a concern, providing a more even skin complexion.[4] For this purpose, concentrations of up to 2% α-arbutin are found in face creams and serums and 0.5% in body creams.[1]

α-Arbutin showed a significant reduction in melanin synthesis in cultured human melanoma cells and a three-dimensional human skin model, with melanin synthesis reduced to 40% of the control, indicating its potency as a skin lightening agent without affecting cell viability.[4]

Mechanism of action[edit]

α-Arbutin's mechanism of action as a skin lightening agent is primarily through the competitive enzymatic inhibition of tyrosinase, leading to a decrease in melanin production without affecting the mRNA gene expression of tyrosinase. It is more potent an inhibitor of tyrosinase than arbutin.[2]

α-Arbutin directly inhibits the enzymatic activity of tyrosinase, which is essential for melanin synthesis. Tyrosinase catalyzes the first two steps in melanin production: the hydroxylation of tyrosine to l-DOPA and the oxidation of l-DOPA to dopaquinone. By inhibiting tyrosinase, α-arbutin reduces the formation of melanin in melanocytes.[5]

α-Arbutin does not affect the gene expression of tyrosinase mRNA. This means that while α-arbutin inhibits the activity of the tyrosinase enzyme, it does not decrease the enzyme's production at the genetic level.[2][6]

This reduction in melanin leads to lighter skin tones and can help in the treatment of hyperpigmentation disorders. The efficacy of α-arbutin in reducing melanin synthesis was demonstrated in cultured human melanoma cells and a three-dimensional human skin model, where it effectively reduced melanin synthesis.[4]

Safety and regulation[edit]

α-Arbutin is generally considered safe for topical application in cosmetic products. However, its usage concentrations in the European Union (EU) are restricted by the European Commission Scientific Committee on Consumer Safety to 2% in facial creams and 0.5% in body lotions.[7][1]

References[edit]

  1. ^ a b c d e "SCCS (Scientific Committee on Consumer Safety), Opinion on the safety of alpha- (CAS No. 84380-018, EC No. 617-561-8) and beta-arbutin (CAS No. 497-76-7, EC No. 207-8503) in cosmetic products, preliminary version of 15-16 March 2022, final version of 31 January 2023, SCCS/1642/22" (PDF). European Commission. 2023-02-01. Retrieved 2023-03-07.
  2. ^ a b c Migas, Piotr; Krauze-Baranowska, Mirosława (2015-09-01). "The significance of arbutin and its derivatives in therapy and cosmetics". Phytochemistry Letters. 13: 35–40. Bibcode:2015PChL...13...35M. doi:10.1016/j.phytol.2015.05.015. ISSN 1874-3900.
  3. ^ Polouliakh, Natalia; Ludwig, Vanessa; Meguro, Akira; Kawagoe, Tatsukata; Heeb, Oliver; Mizuki, Nobuhisa (2020-11-04). "Alpha-Arbutin Promotes Wound Healing by Lowering ROS and Upregulating Insulin/IGF-1 Pathway in Human Dermal Fibroblast". Frontiers in Physiology. 11. doi:10.3389/fphys.2020.586843. hdl:20.500.11850/452340. ISSN 1664-042X. PMC 7672191. PMID 33250779.
  4. ^ a b c Sugimoto, Kazuhisa; Nishimura, Takahisa; Nomura, Koji; Sugimoto, Kenji; Kuriki, Takashi (2004). "Inhibitory Effects of .ALPHA.-Arbutin on Melanin Synthesis in Cultured Human Melanoma Cells and a Three-Dimensional Human Skin Model". Biological and Pharmaceutical Bulletin. 27 (4): 510–514. doi:10.1248/bpb.27.510. ISSN 0918-6158. PMID 15056856.
  5. ^ Sugimoto, Kazuhisa; Nishimura, Takahisa; Nomura, Koji; Sugimoto, Kenji; Kuriki, Takashi (2004). "Inhibitory Effects of .ALPHA.-Arbutin on Melanin Synthesis in Cultured Human Melanoma Cells and a Three-Dimensional Human Skin Model". Biological and Pharmaceutical Bulletin. 27 (4): 510–514. doi:10.1248/bpb.27.510. ISSN 0918-6158. PMID 15056856 – via J-STAGE.
  6. ^ Hori, Ikuyo; Nihei, Ken-ichi; Kubo, Isao (2004-07-27). "Structural criteria for depigmenting mechanism of arbutin". Phytotherapy Research. 18 (6): 475–479. doi:10.1002/ptr.1456. ISSN 0951-418X. PMID 15287073. S2CID 32669940.
  7. ^ Pinto, Marta (2022-04-12). "SCCS preliminary opinion on alpha-arbutin and beta-arbutin". Critical Catalyst. Retrieved 2024-03-08.
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