title: Low molecular weight gelators based on biosurfactants, cellobiose lipids by Cryptococcus humicola.
abstract: Cellobiose lipids (CLs) are bolaform glycolipid biosurfactants, which are produced from natural resources by a yeast strain and show fungicidal activity. In this study, the gelation properties of CL in solvents were investigated by several techniques including rheology and atomic force microscopy (AFM). The yeast CL was found to gelate 6 out of 26 solvents. Although it did not provide gels in ethanol or 1, 3-butanediol which are widely used for cosmetic industries, we succeeded in producing gels by mixing ethanol or 1, 3-butanediol with water. AFM observation of the gels on a silicon substrate provided 3D supramolecular structures with an entangled fibrous network. Moreover, it was also found that some of fibrous structures were twisted helical ribbons. This should be due to the cellobiose backbone having several chiral functional groups. The sol-gel phase transition temperatures for gels in mixed ethanol/water and 1, 3-butanediol/water systems were below 100°C, indicating that the gels can be obtained with rather mild preparation conditions. The present CL gels would be useful for novel multifunctional materials applicable to various industries.
authors.affiliation: Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology-AIST, Tsukuba, Ibaraki, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Imura
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kawamura
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ishibashi
authors.forename: Tomotake
authors.initials: T
authors.lastname: Morita
authors.forename: Shun
authors.initials: S
authors.lastname: Sato
authors.forename: Tokuma
authors.initials: T
authors.lastname: Fukuoka
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kikkawa
authors.forename: Dai
authors.initials: D
authors.lastname: Kitamoto
mesh_terms: D002475:Cellobiose / Q000737:chemistry*; D003454:Cryptococcus / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008970:Molecular Weight; D012212:Rheology; D012997:Solvents / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors
chemical_list: D005782:Gels; D008055:Lipids; D012997:Solvents; D013501:Surface-Active Agents; D002475:Cellobiose