Description
May cause depigmentation
Chemical Properties
cream to beige-light brownish crystals or
Uses
Hydroquinone monobenzyl ether is an antidegradant added to rubber products; inhibitor in acrylic resins.
Uses
PBP is used as antiinflammatory, antisecretory, antiulcer.
Definition
ChEBI: The monobenzyl ether of hydroquinone. It is used as a topical drug for medical depigmentation.
Indications
Monobenzone (Benoquin) potently inhibits melanin
production and destroys melanocytes. Like hydroquinone,
monobenzone was originally introduced for
the topical treatment of disorders of excess melanin pigmentation,
including melasma. It is now used only to
permanently depigment the remaining normally pigmented
skin in patients with extensive vitiligo. Irritant
and allergic contact dermatitis are common side effects.
Preparation
4-Benzyloxyphenol Synthesis: Add 2.63g (0.028mol) of hydroquinone to a 100mL conical flask, weigh 1.12g (0.028mol) of sodium hydroxide, add 8mL of water, wait for the sodium hydroxide to dissolve and add dropwise to the conical flask with hydroquinone, shake well, then add 15mL of DMF and 2.52g (0.02mol) of benzyl chloride, under microwave radiation power of 320W The reaction was cooled to room temperature at the end of the reaction. The reaction was first adjusted to alkalinity with 10% sodium hydroxide, filtered, and the filtrate was washed with 10% sodium hydroxide until the filtrate was colorless (the filtrate was hydroquinone bis(benzyl ether), which could be recycled). The filtrate was acidified with hydrochloric acid to make Monobenzone completely precipitated, and then washed by filtration and ice water, recrystallized with alcohol and water, and decolorized by activated carbon to obtain 2.55g of white solid, the yield was 63.79%.
Brand name
Benoquin (Valeant).
Origin
Monobenzone (monobenzyl ether of hydroquinone, MB) is a depigmenting agent that was discovered by Oliver et al. in 1939. It has been approved by the FDA as a cream formulation for skin depigmentation of patients with vitiligo. The mechanism of action for depigmentation by MB is correlated with the inhibition of tyrosinase[1]. The compound also is cytotoxic to melanocytes and melanoma cells and increases melanocyte and melanoma cell immunogenicity.
Biological Activity
The skin-depigmenting effect of MB is correlated with the inhibition of tyrosinase, the rate-limiting enzyme in melanin synthesis, in both melanocytes and melanoma cells. The metabolites of MB have been proven to exert toxic effects on melanocytes and increase melanocyte and melanoma cell immunogenicity. MB potently inhibited RNR enzyme activity by targeting RRM2 and thereby suppressed AML cell growth in vitro and in a mouse xenograft experiment[1-2].
Side effects
Side effects:
Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
Intense itching, blistering, burning, or swelling of the skin.
Mild skin rash, tenderness, or redness.
Purification Methods
Crystallise it from EtOH or H2O, and dry (P2O5) under vacuum. [Walter et al. J Am Chem Soc 108 5210 1986, Beilstein 6 IV 5778.]
References
[1] Jingwen Dong. “Identification of Monobenzone as a Novel Potential Anti-Acute Myeloid Leukaemia Agent That Inhibits RNR and Suppresses Tumour Growth in Mouse Xenograft Model.” Cancers (2022).
[2] Jasper G. van den Boorn . “Skin-Depigmenting Agent Monobenzone Induces Potent T-Cell Autoimmunity toward Pigmented Cells by Tyrosinase Haptenation and Melanosome Autophagy.” Journal of Investigative Dermatology 131 6 (2011): Pages 1240-1251.
