Cyclodextrin production

Cyclodextrins, products of the degradation of starch by an amylase of Bacillus macerans(1), have been studied in terms of chemical modifications, mainly for the purpose of developing efficient enzyme mimics(2). Not only their unique cyclic structures, but also their ability to form Inclusion complexes with suitable organic molecules, led us to Investigate the total synthesis of this class of molecules(3) We describe here an approach to a total synthesis of alpha(l), gamma(2), and "iso-alpha" cyclodextrin (3). 

The stability of orange peel oil depends on the selection of the encapsulation process and the encapsulating agent. The results of this study indicated that the differences in shelf life were greatly accentuated at higher temperatures. The shelf life of the spray dried products ranged from 5-35 days compared to the extrusion and beta-cyclodextrin products which were still acceptable after 180 days at 50 C. 

In the solvent process,30,31 a solvent is used to direct the reaction to produce only one cyclodextrin. Higher starch concentrations can be used in this process than in the non-solvent process. (Concentrations of 30% are typically used.) Maximum yields per unit volume are achieved at 30% solids in the presence of solvents, compared to a maximum yield at 15% solids using the non-solvent process. The pH of the hydrolyzate is adjusted to the optimum for the enzyme, and the enzyme and solvent are added to the starch hydrolyzate. Solvents typically used for (3-cyclodextrin production include toluene, trichloroethylene and cyclohexane. As the reaction proceeds, (3-cyclodextrin precipitates as an insoluble complex. Yields per unit weight of starch are typically 30—45%, much higher than the yield obtained by the non-solvent process. 

The pathway for the cathodic reduction of acetophenone can be profoundly altered when the aromatic ring is complexed inside the hydrophobic cavity of p-cyclodextrin. Products resulting from ortho and para coupling to the carbonyl carbon are isolated in excellent yield, as shown in equation (2). 

Captisol . In Sulfobutyl Ether -Cyclodextrin Product Literature from CyDex, Inc. 12980 Metcalf Ave., Suite 470, Overland Park, KS 66213,2000, CDinfo cydexinc.com. Coussement, W. Van Cauteren, H. Vandenberghe, J. Vanparys, P. Teuns, G. Lampo, A. Marsboom, R. Toxicological profile of hydroxypropyl [l-cyclodextrin (HP (3-cyclodextrins) in laboratory animals. Minutes 5th International Symposium on Cyelodextrins. Duchene, D., Ed. Editions de Sante Paris, 1990 522-524. 

Entry Substrate Cyclodextrin Product (conv.%)l i Time(h) TOF(h- )l ... 

Martins RE, Plieva EM, Santos A, Hatti-Kaul R (2005) Integrated immobilized cell reactor-adsorptimi system for p-cyclodextrin production A model study using PVA-ciyogel entrapped Raci//t/s agaradharens. Biotechnol Lett 25 1537-1543... 

Gawande, B. N., Patkar, A. Alpha-cyclodextrin production using cyclodextrin glycosyltrans-ferase from Klebsiella pneumoniae AS-22. Starch 2001,53,75-83. 

Lima, H. O., De Moraes, R R, Zanin, G. M. Beta-cyclodextrin production by simultaneous fermentation and cychzation. Appl Biochem Biotechnol 1998,70-72,789-804. 

A high-dextrin syrup adjusted to contain 15% solids and at pH 5-6 is used as substrate for CGTase for cyclodextrin production. These cyclic oligosaccharides are composed of six, seven, or eight glucose units linked by a-1,4 linkages to form, a, p, or Y cyclodextrins, respectively. Cyclodextrins have several useful properties. They impart superior chemical stability to bases and weak acids and excellent thermal stability because they melt at temperatures of 270°C. Their hygroscopicity is low, and they are resistant to amylolytic enzymes. In addition, they are used to enhance chemical stability and reduce volatility of complexed molecules. They also mask unpleasant odors and flavors. 

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