Butanol, particularly 1-butanol (n-butanol), is a primary alcohol solvent in biochemistry, offering greater hydrophobicity than shorter-chain alcohols for selective extraction of lipids and membrane components.

Chemical Properties

1-Butanol (C₄H₉OH) is a linear four-carbon alcohol with a terminal hydroxyl group. It presents a boiling point of approximately 117°C, a melting point of -89.8°C, and a density close to 0.81 g/mL. It is moderately soluble in water (about 77 g/L at 20°C) and miscible with organic solvents such as chloroform and ether. Its dielectric constant (~17.5) provides an intermediate polarity suitable for biphasic extraction systems. 1-Butanol is characterized by a banana-like odor and moderate vapor pressure (6.7 hPa), which facilitates detection and evaporation during handling.

Biochemical Applications

In lipid biochemistry, butanol is used for extracting phospholipids or gangliosides from aqueous phases following Folch-type procedures or modified Bligh-Dyer protocols for tissue lipid isolation prior to TLC or GC-MS analysis. In protein chemistry, cold butanol precipitation can be applied to membrane-associated proteins, allowing recovery with minimal denaturation compared to strong acid precipitants such as TCA. In molecular biology workflows, it may be used for washing polyacrylamide gels or solubilizing certain antibiotics for cell culture applications. Additionally, butanol can assist enzymatic assays by precipitating interfering compounds from crude lysates.