A novel process of cyclodextrin production by the use of specific adsorbents: Part II. A new reactor system for selective production of α-cyclodextrin with specific adsorbent

Synthesis of polyethylene glycol functional bonded silica gel for selective recognition and separation of α-cyclodextrin

In this work, we for the first time synthesized the polyethylene glycol (PEG) bonded silica gel via KH-560 as a silane coupling reagent for column chromatography by a solid/liquid surface continuous reaction method. The molecular interaction, structure, morphology, and thermostability was characterized by fourier transform infrared spectroscopy (FTIR), elemental analysis (EA), scanning electronic microscope (SEM) and thermogravimetric analysis (TGA). Given that PEG is capable to self-assemble with α-CD, the PEG bonded silica gel was used as packing of column chromatography to achieve the selective separation of α-cyclodextrin (α-CD) at room temperature and atmospheric pressure. The bonded silica gel column could realize the effective separation of α-CD in the enzymatic hydrolysis mixture, which provides support for industrial separation of α-CD.

A novel synthesis method for cyclodextrins from maltose in water-organic solvent systems

A novel enzymatic synthesis method of cyclodextrin (CD) from low-mol-wt maltose using cyclomaltodextrin glucanotransferase (CGTase) from Bacillus macerans has been developed in various water-organic solvent systems. A beta-CD was synthesized in a two-phase system consisting of water and cyclohexane. However, no CDs could be synthesized in an aqueous buffer solution. A maximal yield of beta-CD has been obtained at a cyclohexane content volume of 44%. This synthesis has been obtained only at low temperatures, i.e., 7 degrees C, and did not take place at 50 degrees C. In addition, various organic solvents have been used for the enzymatic synthesis of CD from maltose. Consequently, beta-CD could be synthesized in various water-organic solvent systems, e.g., cyclohexane, benzene, xylene, and chloroform, but no enzymatic reaction occurred using aliphatic n-hydrocarbon solvents such as hexane, dodecane, and hexadecane. Furthermore, alpha- and beta-CD could be synthesized in water mixture solutions using organic solvents having an alcoholic group (e.g., ethanol, propanol, butanol, and pentanol) in a wide range of the reaction temperatures, typically 7-50 degrees C. In this temperature range, alpha- and beta-CD were also formed and the maximal yield from maltose to beta-CD of approx 13% was reached in 60 h.