Arbutin, 熊果苷

Arbutin is a glycosylated hydroquinone that has been found in Arctostaphylos plants and has diverse biological activities, including tyrosinase inhibitory, antioxidant, and anti-inflammatory properties. It inhibits human tyrosinase activity in crude tyrosinase solution isolated from human melanocytes (IC50s = 5.7 and 18.9 mM using L-tyrosine and L-DOPA as substrates, respectively) as well as in intact melanocytes (IC50 = 0.5 mM). Arbutin (50 μM) inhibits hemolysis induced by the free radical generator AAPH in sheep erythrocytes and inhibits AAPH-induced decreases in cell viability in cultured human skin fibroblasts when used at concentrations greater than 125 μM. In an LPS-induced rat model of acute lung injury, arbutin (50 mg/kg) prevents increases in IL-1β, IL-6, and TNF-α levels in lung tissue and serum. Formulations containing arbutin have been used in the treatment of hyperpigmentation disorders.

Arbutin analytical standard provided with w/w absolute assay, to be used for quantitative titration.

Arbutin is a β-D-glucopyranoside of hydroquinone, that occurs naturally and which can be used in the treatment of various cutaneous hyperpigmentations. Its mode of action basically involves the inhibition of tyrosinase activity of human melanocytes and also suppresses the production of melanin via inhibition of melanin synthetic enzyme.

Extracted from the dried leaves of bearberry plant in the genus Arctostaphylos and other plants commonly in the Ericaceae family, arbutin is a beta-D-glucopyranoside of [DB09526]. It is found in foods, over-the-counter drugs, and herbal dietary supplements. Most commonly, it is an active ingredient in skincare and cosmetic products as a skin-lightening agent for the prevention of melanin formation in various skin conditions that involve cutaneous hyperpigmentation or hyperactive melanocyte function. It has also been used as an anti-infective for the urinary system as well as a diuretic. Arbutin is available in both natural and synthetic forms; it can be synthesized from acetobromglucose and [DB09526]. Arbutin is a competitive inhibitor of tyrosinase (E.C.1.14.18.1) in melanocytes, and the inhibition of melanin synthesis at non-toxic concentrations was observed in vitro. Arbutin was shown to be less cytotoxic to melanocytes in culture compared to [DB09526].

Hydroquinone O-beta-D-glucopyranoside is a monosaccharide derivative that is hydroquinone attached to a beta-D-glucopyranosyl residue at position 4 via a glycosidic linkage. It has a role as a plant metabolite and an Escherichia coli metabolite. It is a beta-D-glucoside and a monosaccharide derivative. It derives from a hydroquinone.

Inhibitor of tyrosinase in melanocytes: skin whitener

Title: Arbutin

CAS Registry Number: 497-76-7

CAS Name: 4-Hydroxyphenyl-b-D-glucopyranoside

Additional Names: hydroquinone-b-D-glucopyranoside; hydroquinone glucose; arbutoside; ursin

Molecular Formula: C12H16O7

Molecular Weight: 272.25

Percent Composition: C 52.94%, H 5.92%, O 41.14%

Literature References: Naturally occurring glycoside of hydroquinone, q.v., found in the bark and leaves of various plants, usually occurring together with methylarbutin. Principal antibacterial constituent of the traditional medicine, uva ursi, q.v. Isoln from bearberry leaves (Arctostaphylos uva-ursi Spreng., Ericaceae): A. Kawalier, Ann. 82, 241 (1852); from leaves of blueberry, cranberry, and pear (Pyrus communis L., Rosaceae): G. Urban, M. Rogowski, Arch. Exp. Pathol. Pharmakol. 211, 194 (1950). Synthesis: C. Mannich, Arch. Pharm. 250, 547 (1912); A. Robertson, R. B. Waters, J. Chem. Soc. 1930, 2729. Production by plant cell culture: S. Inomata et al., Appl. Microbiol. Biotechnol. 36, 315 (1991). Physical properties: E. Lindpainter, Arch. Pharm. 277, 398 (1940). Determn in drug prepns: L. Kraus, Pharmazie 19, 41 (1964); E. Kenndler et al., J. Chromatogr. 514, 383 (1990). Inhibition of human melanin synthesis in vitro: K. Maeda, M. Fukuda, J. Pharmacol. Exp. Ther. 276, 765 (1996). Review of human exposure: P. J. Deisinger et al., J. Toxicol. Environ. Health 47, 31-46 (1996).

Properties: Occurs as the monohydrate. Colorless elongated prisms from moist ethyl acetate, mp 199° after sintering at 163-164° (Robertson, Waters). Also reported as unstable form, mp 165°; stable form, mp 199.5-200° (Lindpaintner). [a]D20 -60.3° (in water). Sol in water and in alc.

Melting point: mp 199° after sintering at 163-164° (Robertson, Waters); unstable form, mp 165°; stable form, mp 199.5-200° (Lindpaintner)

Optical Rotation: [a]D20 -60.3° (in water)

Derivative Type: Methylarbutin

CAS Registry Number: 6032-32-2

CAS Name: 4-Methoxyphenyl-b-D-glucopyranoside

Additional Names: methylarbutoside

Molecular Formula: C13H18O7

Molecular Weight: 286.28

Percent Composition: C 54.54%, H 6.34%, O 39.12%

Properties: Crystallizes from water as the monohydrate, mp 158-160°; solidifies and melts again at 175° (Mannich). Also reported as unstable form, mp 160.5°; stable form, mp 176° (Lindpaintner). [a]D20 -60.66° (in water). Sol in hot water or alcohol; slightly sol in ether.

Melting point: mp 158-160°; solidifies and melts again at 175° (Mannich); unstable form, mp 160.5°; stable form, mp 176° (Lindpaintner)

Optical Rotation: [a]D20 -60.66° (in water)

 Use: In cosmetics as skin lightening agent.