Physicochemical characterization of 6-O-acyl trehalose fatty acid monoesters in desiccated system

Shigesaburo Ogawa; Koji Honda; Taro Tsubomura; Kiichiro Totani; Isao Takahashi; Setsuko Hara

doi:10.1016/j.chemphyslip.2018.09.012

Physicochemical characterization of 6-O-acyl trehalose fatty acid monoesters in desiccated system

Chem Phys Lipids. 2018 Nov:216:80-90. doi: 10.1016/j.chemphyslip.2018.09.012. Epub 2018 Sep 29.

Authors

Shigesaburo Ogawa¹, Koji Honda², Taro Tsubomura³, Kiichiro Totani⁴, Isao Takahashi⁵, Setsuko Hara⁶

Affiliations

¹ Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, 3-3-1 Kichijojikitamachi, Musashino-shi, Tokyo, 180-8633, Japan. Electronic address: s.ogawa@st.seikei.ac.jp.
² Hyogo prefectural institute of technology, yukihira-cho 3-1-12, Suma-ku, Kobe, 654-0037, Japan. Electronic address: honda@hyogo-kg.jp.
³ Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, 3-3-1 Kichijojikitamachi, Musashino-shi, Tokyo, 180-8633, Japan. Electronic address: tsubomura@st.seikei.ac.jp.
⁴ Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, 3-3-1 Kichijojikitamachi, Musashino-shi, Tokyo, 180-8633, Japan. Electronic address: ktotani@st.seikei.ac.jp.
⁵ Department of Physics, School of Science and Technology, Kwansei Gakuin University, Sanda 669-1337, Japan. Electronic address: suikyo@kwansei.ac.jp.
⁶ Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, 3-3-1 Kichijojikitamachi, Musashino-shi, Tokyo, 180-8633, Japan. Electronic address: shara@st.seikei.ac.jp.

PMID: 30273546
DOI: 10.1016/j.chemphyslip.2018.09.012

Abstract

The understanding of the basic physicochemical properties of trehalose lipid is indispensable to extending their availability. In this study, the hydrate crystal (Cr), the liquid crystalline (LC) phase and the glassy state formations of 6-O-acyl trehalose fatty acid monoester (TREn) were examined under in a desiccated system. TREn (n = 10, 12, 14, 16) formed monohydrate Cr and showed the hydrate Cr-glassy fluid lamellar LC (Lα) phase transition via dehydration in the heating process. Here, Lα phase for TRE10 and TRE12 was kinetically formed by the dehydration below the glass transition temperature (T_g). On the dehydration temperature (T_deh), T_gs, and heat capacity changes (ΔC_ps) at these T_gs, no distinct effects by the difference of the acyl chain length were recognized, possibly because the core structure of containing sugar hydrate Cr or sugar moieties should be similar regardless of the acyl chain length. Besides, TRE10 having a relatively high hydrophilic/hydrophobic balance (HLB) afforded to form the cubic LC (Q) phase and the corresponding glassy phase, while TRE14 and TRE16 having low HLB afforded the Lα phase as well as the corresponding glassy phases above T_g. TRE12 having middle HLB afforded both LCs and the corresponding glassy phase by controlling the kinetics of LC-LC phase transition between Lα and Q phases. Furthermore, the anomalous reversible phase transition during both the heating and cooling processes was also ascertained in the glassy phase for TRE16, which was considered the phase transition between glassy Lα and glassy lamellar gel (Lβ) phase. It greatly empathizes the two-dimensional trehalose glass layer and fluid hydrocarbon chains in the TREn glassy phase. Thus, in this study, it was demonstrated that TREn as the simplest trehalose lipid exhibited the glassy formation performance as well as the hydrate Cr formation, which showed less chain length dependence, together with the LC formation and the phase transition between glassy Lα and glassy Lβ phase, which depended on chain length greatly.

Keywords: Glass transition; Hydrate crystal; Lamellar gel glass; Liquid crystal; Trehalose fatty acid ester; Trehalose lipids.

MeSH terms

Chemistry, Physical
Esters / chemistry*
Fatty Acids / chemistry*
Lipids / chemistry*
Trehalose / chemistry*

Substances

Esters
Fatty Acids
Lipids
Trehalose