Liposomes composed of unsaturated lipids were more stable than those containing saturated lipids toward DMe‐β‐CDx, DMe‐α‐CDx and DMe‐β‐CDx. The Hill coefficient values (n) indicated that the saturated lipid•DMe‐CDx complexes had stoichiometric ratios in the range of 1:3‒1:4, while the unsaturated lipid•DMe‐CDx complexes had ratios in the range of 1:1.5‒1:3. That is, a cis alkene group in the unsaturated lipids prevented complexation with a second DMe‐CDx in the direction toward each acyl chain. Furthermore, the liposomes composed of the unsaturated lipids were much slower to form precipitates upon the addition of α‐CDx than those of the saturated lipids. To the best of our knowledge, this is the first example showing that CDxs interact with unsaturated lipids.

This work was supported by the Japanese Society for the Promotion of Science (JSPS) KAKENHI a Grant‐in‐Aid for Scientific Research (B) (Grant No. 25288037 and No. 16H04133) and a Grant‐in‐Aid for Challenging Exploratory Research (Grant No. 16K13982).