Description
Arbutin is a hydroquinone compound derived from houyeyanbaicai 厚叶岩白菜 (Bergenia crassifolia (L.) Fritsch.). It is also distributed in wufanshu (Vaccinium bracteatum Thunb.), and xiongguo (bearberry), Pear tree, jishutiao (Viburnum opulus Linn. var.calvescens (Rehd.) Hara f. calvescens), xingxiangtuerfeng (Ainsliaea fragrans Champ.), heiguoxianleihuaqiu (Aronia melanocarpa), nvzhen (Ligustrum lucidum Ait.), juanbai (Selaginella tamariscina (Beauv.) Spring), maodadingcao (Gerbera piloselloides (L.) Cass), payanhong (Veronicastrum axillare (Sieb. and Zucc.) Yamazaki), and yueju (Vaccinium vitis-idaea Linn.) also contain this compound . In addition, it can be obtained from biotransformation, enzyme synthesis, and organic synthesis .
Chemical Properties
Crystalline powder
Physical properties
Appearance: white powder. Solubility: soluble in hot water. Melting point: 198–201?°C
History
Arbutin is a hydroquinone compound with two epimers, α and β arbutin. The sources
of α-arbutin and β-arbutin are completely different. β-arbutin can be prepared by
plant extraction, plant cell culture, and artificial synthesis. Arbutin can relieve cough
and asthma and has whitening effect.
The Japanese cosmetics company Shiseido developed the arbutin as a whitening
agent in the 1990s. Arbutin can not only reduce skin freckles, senile plaques, and
chloasma but also relieve acne and improve healing after skin burns. Arbutin is the
epimer of β-arbutin, and the spatial orientation of their glycosidic bonds is just the
opposite. Alpha arbutin is generally prepared by different microbial enzymes. A
molecule of glucose and a molecule of hydroquinone combine to form a molecule
α-arbutin . Alpha arbutin improves ultraviolet burn scar. α-Arbutin can be used in
a variety of skin whitening cosmetics since it is chemically stable.
Definition
ChEBI: A monosaccharide derivative that is hydroquinone attached to a beta-D-glucopyranosyl residue at position 4 via a glycosidic linkage.
Indications
Arbutin has bactericidal, anti-inflammatory, and whitening effects and is mainly used in whitening cosmetics.
Pharmacology
Arbutin could effectively inhibit the activity of tyrosinase in skin cells and block the formation of melanin without affecting cell proliferation . Furthermore, it could accelerate the decomposition and excretion of melanin and thereby reduce skin pigmentation and eliminate freckles. In addition, arbutin shows no toxicity, irritation, sensitization, and other side effects . Alpha arbutin is safer and has a stronger inhibitory effect on tyrosinase. At present the whitening cosmetics market in the developed countries has been almost monopolized by arbutin.
Clinical Use
Arbutin is mainly used in high-level cosmetics and has been formulated into skin cream, freckle cream, and senior pearl cream. Arbutin is a major component of medicine for treating burn and scald, characterized by rapid elimination of pain and swelling and fast healing, leaving no scars. Arbutin can also be used as raw materials for intestinal anti-inflammatory drug, with sterilization, anti-inflammatory effect, and nontoxic side effects.
Purification Methods
The glycoside from Protea exima is purified by recrystallisation from H2O or moist EtOAc (as monohydrate), after chromatography through silica Gel using EtOAc/MeOH. Crystallisation from EtOH/CHCl3 gives crystals m 199-200o with intermediate melting at 164o and resolidifying. The pentaacetate crystallises from EtOH in fine needles with m 145-146o, [] D 20 -28.2o (c 2, Me2CO). [Robinson & Waters J Chem Soc 2729 1930, IR, NMR, MS: Perold et al. J Chem Soc, Perkin Trans 1 239 1979, Beilstein 17/7 V 110.]
