2. Cyclodextrins An Overview Matthias Arenskötter Florence Folmer Chris Llewellyn Aurélie Pardo Frank Reinecke Grazia Trebbi Gent 2001

3. 1. Introduction 2. Microbial Production 3. Purification And Fractionation 4. Properties 5. Applications Cyclodextrins - An Overview

4. Introduction Cyclodextrins (CDs) are torus shaped cyclic oligomers consisting of 6 ( ),7 ( ) or 8 ( -CD) glucose units with -1,4-linkages with a hydrophobic cavity and a hydrophilic exterior

5. Introduction History: 1891 Discovery, Villiers 1903 Descriptions of properties, Shardinger 1939 Tilden and Hudson were able to show that the conversion of starch to CD was due to the action of an enzyme, CD Glycosyl-Transferase (CGTase), which was secreted into the culture medium.

6. Introduction 1957 Complexation ability of CDs widely accepted; Cramer, French 1981 First International Symposium on CDs, Szejtli 1987 Total synthesis, Ogawa 1994 Total synthesis of cyclo[D-Glcp(1->4)] 5

7. Introduction Today CDs are only synthesized either by fermentation or enzymatically. Many CGTases from different microorganisms are known, cloned, sequenced, characterized and used for production of CDs.

8. Introduction Applications: Because of their unique properties CDs allow packaging on a molecular level of various molecules which is applied in pharmaceutics, food and flavours etc... Used in chromatographic columns CDs can separate stereoisomers. Derivatives of CDs can even be used to mimic enzymes.

9. 1. Introduction 2. Microbial Production 3. Purification And Fractionation 4. Properties 5. Applications Cyclodextrins - An Overview

10. Microbial Production CGTases are produced by many different bacterial species of the genus Bacillus but also by Flavobacterium sp., Klebsiella pneumoniae and Micrococcus sp. Genes have been cloned and recombinantly expressed in Escherichia coli and other organisms, including for example Solanum tuberosum (Potato).

11. The CGTase acts on linear starch and transfers a part of the chain (F) to its own non-reducing end (A) as indicated in this model: Microbial Production CGTase A BC D EF GH starch A BC D EF GH -CD

12. 1. Introduction 2. Microbial Production 3. Purification And Fractionation 4. Properties 5. Applications Cyclodextrins - An Overview

13. Enzymatic synthesized CDs are selectively precipitated by organic solvents. Purification and Fractionation

14. 1. Introduction 2. Microbial Production 3. Purification And Fractionation 4. Properties 5. Applications Cyclodextrins - An Overview

15. Properties Important Properties: CDs have hydrophobic cavities of different sizes enabling the complexation of hydrophic guest molecules. These complexes represent a solution for insolubility. They have neither a reducing nor a non- reducing end-group.

16. Properties Stability: CDs are not decomposed by hot aqueous alkali and rather resistant to acid hydrolysis. CDs are resistant to -amylases (except microbial enzymes) and they are completely resistant to yeast-fermentation and -amylases.

17. Properties

19. 1. Introduction 2. Microbial Production 3. Purification And Fractionation 4. Properties 5. Applications Cyclodextrins - An Overview

20. Applications Pharmaceutical industry: Treatment of inflammation or throat infection (with iodine) Coronary dilatation (with nitroglycerin) Anti-ulcerate (with benexate) Vectors for vitamins or hormones Reduction of side-effects and increase in efficiency of anti-cancer drugs

21. Applications Pharmaceutical industry: Solid Complex Dissolution (k d ) Dissolved Complex Adsorption (k a ) (k c ) Cyclodextrin Competing Agent Competing Agent- Cycloddextrin Complex (k i ) Drug Biomembrane Systemic Circulation

22. Applications Cosmetics & Hygiene: Long-lasting perfume release Deodoriser (with peppermint oil, i.e.) Removal of dryness wrinkles (with seaweed compounds, Vitamin A & E) Anti-cellulitis compound Shampoo industry Teeth cleaning, anti-plaque compound Antibacterial in refrigerators

23. Applications Food industry: Emulsion stabiliser Taste-masking Long-lasting flavouring Removal of cholesterol from milk, butter, eggs, a.o.

24. Applications Paint industry: Increase in compatibility of paint ingredients Increase in stability of the paint Increase in the range of colours and in the quality of dyes

25. Applications Environmental protection: Reduction in oxidiser requirements in paper production Environmentally friendly oil-spill clean-up Treatment of tree-wounds (with auxin) Mobilisation of toxins without leaving toxic residues behind (innovative technique)

26. Applications Environmental protection: Removal or detoxification of waste material, esp. aromatic pollutants Use in agriculture to increase the stability and the efficiency of herbicides, insecticides, repellents,…

27. Applications Chemical and biochemical applications: Reaction catalyst in adhesives Use in chromatography (separation of stereoisomers) Increase in speed of diagnostic test reaction

28. Applications Chemical and biochemical applications: Enzyme mimicry Dimer of -cyclodextrin linked on primary side by a metal-binding-group as catalyst of hydrolysis of a phosphate diester

29. Summary When Cyclodextrins were discovered they were just a chemical curiosity but today a lot of applications are known. Due to intensive studies and advances in production procedures prices continue to decrease making CDs attractive for many applications. To date more than 3300 European Patents are registered indicating great industrial interest.

30. Group Members Matthias Arenskötter, Westfälische Wilhelms- Universität Münster, Germany Florence Folmer, University of Wales Bangor, UK Chris Llewellyn, University of Wales Swansea, UK Aurélie Pardo, Institue Nationale Polytechnique de Toulouse, France Frank Reinecke, Westfälische Wilhelms- Universität Münster, Germany Grazia Trebbi, Universita´ di Bologna, Italy