On the importance of hydroxyl groups in the polar head-group of nonionic surfactants and membrane lipids.

In this review properties of natural membrane lipids and surfactants synthesized from natural substances, such as paraffin chain alcohols and carbohydrates, are compared with those of synthetic surfactants of the polyoxyethylene type. Special attention is paid to the characteristic solution properties of nonionic surfactants with hydroxyl groups as the hydrophilic moiety, including alkyl glyceryl ethers and alkyl glucosides and maltosides, which are compared with those with oxyethylene groups. The major properties of the hydrophilic moiety are lipophobicity and hydrophilicity. Lipophobicity is an important property of oil-soluble surfactants, in particular for the polyoxyethylene alkyl ether type of surfactants where a too high lipophobicity may result in solubility in water.