Bringing membrane proteins into aqueous solution generally requires the use of detergents or other amphiphilic agents. The invention provides a new class of amphiphiles, each of which includes a multi-fused ring system as a lipophilic group. These new amphiphiles confer enhanced stability to a range of membrane proteins in solution relative to conventional detergents, leading to improved structural and functional stability of membrane proteins, including integral membrane proteins. Accordingly, the invention provides new amphiphiles for biochemical manipulations and characterization of membrane proteins. These amphiphiles display favorable behavior with membrane proteins and can be used to aid the solubilization, isolation, purification, stabilization, crystallization, and/or structural determination of membrane proteins.