Dimethyl sulfoxide (DMSO) is a colorless organosulfur compound with the formula (CH3)2S=O. It is a widely used polar aprotic solvent that dissolves both polar and nonpolar substances and mixes well with water and many organic solvents. DMSO has a high boiling point and can leave a garlic-like taste when absorbed through the skin. Its structure features a trigonal pyramidal geometry around a tetrahedral sulfur atom with Cs symmetry.
🏭⚗️ production
DMSO was first synthesized in 1866 by Alexander Zaytsev. It is now industrially produced from dimethyl sulfide, a by-product of the kraft process, through oxidation with oxygen or nitrogen dioxide.
🧪 Applications
DMSO is less toxic than other polar aprotic solvents and is widely used in reactions involving salts and nucleophilic substitutions like the Finkelstein reaction. It’s also common in biochemistry and cell biology as an extractant. Its weak acidity makes it ideal for carbanion studies, and many non-aqueous pKa values have been measured using DMSO. Due to its high boiling point and slow evaporation, DMSO is difficult to remove completely, often requiring water addition and cryodesiccation. In its deuterated form (DMSO-d6), it is a useful NMR solvent, despite drawbacks like high viscosity and water absorption.
DMSO is widely used in in vitro drug screening and high-throughput programs due to its solubility and stability. However, it can affect cell viability at different concentrations. It is also used in in vivo studies, but its biological effects require careful control group planning due to possible interactions, such as protection against liver damage from drugs like acetaminophen.
Medical use
Since the 1960s, DMSO has been used medically for its ability to penetrate skin and membranes. It is applied as a topical analgesic, anti-inflammatory, antioxidant, and transdermal drug delivery vehicle. It enhances penetration of compounds, including antifungals into nails. The FDA has approved DMSO only for treating interstitial cystitis, although studies show it may help other inflammatory genitourinary conditions.
⚠️ Safety
DMSO can carry harmful substances through the skin, affecting the action of many drugs. Proper glove selection is crucial; materials like butyl rubber or thick latex offer better protection, while nitrile gloves degrade quickly with DMSO exposure.
