4
Cyclodextrins are cyclic oligomers obtained from the enzymatic degradation of
starch. They are one of the most remarkable macrocyclic molecules with significant
impacts in our daily lives. Cyclodextrins have a particular structure composed of a
hydrophobic cavity that can encapsulate other substances to form inclusion complexes through host-guest interactions. This characteristic feature is at the origin of
many applications. Today, all industrial sectors are concerned, e.g., pharmaceuticals, cosmetics, food, hygiene and toiletries, biotechnology, medical, radiology,
agrochemistry, catalysis, packaging, textile industry, nanotechnology, and soil and
water treatment.
The French pharmacist Villiers published the first reference to cyclodextrins in
1891 (Villiers 1891a, b, c, d). Since the beginning of the twentieth century,
Schardinger, Pringsheim, Karrer, Freudenberg, French, Cramer, Casu, Bender,
Saenger, Nagai, Szejtli, and Pitha have marked the history of cyclodextrins (Szejtli
1998; Loftsson and Duchêne 2007; Kurkov and Loftsson 2013; Crini 2014; MorinCrini et al. 2015; Crini et al. 2018).
The first important period on the history of cyclodextrins, from 1891 to 1911,
covers their discovery by Villiers, and their characterization and chemistry by
Schardinger (Thoma and Stewart 1965; Caesar 1968; Clarke et al. 1988; Szejtli
1998). In 1891, Villiers discovered a crystalline dextrin from the Bacillus amylobacter digest of potato starch, which he named cellulosine. At the beginning of the
last century, Schardinger also observed the formation of two crystallized products
during his investigations of food spoilage, which he called crystallized dextrin-α
and crystallized dextrin-β. Schardinger gave the first detailed description of the
preparation and separation of these two dextrins. He was also the first to isolate the
strain of bacteria responsible for dextrin formation, i.e., Bacillus macerans.
However, from 1911 to 1935 came a period of doubt and disagreement, in particular
between the groups of Pringsheim and Karrer, although they published numerous
studies on the composition, properties, and chemistry of the crystallized dextrins
(Crini 2014).
It was not until the mid-1930s that research on dextrins developed again. The
exploration period from 1935 to 1950 was marked by the numerous results obtained
by Freudenberg and French on the structure of the “Schardinger dextrin” molecules.
In 1935, Freudenberg was the first to develop a relatively simple method for the
obtention and purification of the two Schardinger dextrins. Freudenberg also suggested in 1936 a cyclic structure for α-dextrin and β-dextrin, which was confirmed
in 1938. In the 1940s, French proposed that Schardinger dextrins be called cycloamyloses and described new protocols for the preparation of cycloamyloses with high
purity. In 1942, Hudson discovered the enzyme in Bacillus macerans responsible
for the conversion of starch into dextrins, and the same year, French published the
exact molecular weights of the cyclohexaamylose and cycloheptaamylose, i.e.,
α-dextrin and β-dextrin, respectively. In 1948, Freudenberg discovered γ-dextrin or
cyclooctaamylose, and 1 year later, Cramer, his PhD student, introduced the
cyclodextrin- based nomenclature. From 1950 onward, this terminology was increasingly used although the nomenclature of cyclodextrins remained a subject of debate
until the end of the 1990s.
N. Morin-Crini et al.
Cyclodextrins are cyclic oligomers obtained from the enzymatic degradation of
starch. They are one of the most remarkable macrocyclic molecules with significant
impacts in our daily lives. Cyclodextrins have a particular structure composed of a
hydrophobic cavity that can encapsulate other substances to form inclusion complexes through host-guest interactions. This characteristic feature is at the origin of
many applications. Today, all industrial sectors are concerned, e.g., pharmaceuticals, cosmetics, food, hygiene and toiletries, biotechnology, medical, radiology,
agrochemistry, catalysis, packaging, textile industry, nanotechnology, and soil and
water treatment.
The French pharmacist Villiers published the first reference to cyclodextrins in
1891 (Villiers 1891a, b, c, d). Since the beginning of the twentieth century,
Schardinger, Pringsheim, Karrer, Freudenberg, French, Cramer, Casu, Bender,
Saenger, Nagai, Szejtli, and Pitha have marked the history of cyclodextrins (Szejtli
1998; Loftsson and Duchêne 2007; Kurkov and Loftsson 2013; Crini 2014; MorinCrini et al. 2015; Crini et al. 2018).
The first important period on the history of cyclodextrins, from 1891 to 1911,
covers their discovery by Villiers, and their characterization and chemistry by
Schardinger (Thoma and Stewart 1965; Caesar 1968; Clarke et al. 1988; Szejtli
1998). In 1891, Villiers discovered a crystalline dextrin from the Bacillus amylobacter digest of potato starch, which he named cellulosine. At the beginning of the
last century, Schardinger also observed the formation of two crystallized products
during his investigations of food spoilage, which he called crystallized dextrin-α
and crystallized dextrin-β. Schardinger gave the first detailed description of the
preparation and separation of these two dextrins. He was also the first to isolate the
strain of bacteria responsible for dextrin formation, i.e., Bacillus macerans.
However, from 1911 to 1935 came a period of doubt and disagreement, in particular
between the groups of Pringsheim and Karrer, although they published numerous
studies on the composition, properties, and chemistry of the crystallized dextrins
(Crini 2014).
It was not until the mid-1930s that research on dextrins developed again. The
exploration period from 1935 to 1950 was marked by the numerous results obtained
by Freudenberg and French on the structure of the “Schardinger dextrin” molecules.
In 1935, Freudenberg was the first to develop a relatively simple method for the
obtention and purification of the two Schardinger dextrins. Freudenberg also suggested in 1936 a cyclic structure for α-dextrin and β-dextrin, which was confirmed
in 1938. In the 1940s, French proposed that Schardinger dextrins be called cycloamyloses and described new protocols for the preparation of cycloamyloses with high
purity. In 1942, Hudson discovered the enzyme in Bacillus macerans responsible
for the conversion of starch into dextrins, and the same year, French published the
exact molecular weights of the cyclohexaamylose and cycloheptaamylose, i.e.,
α-dextrin and β-dextrin, respectively. In 1948, Freudenberg discovered γ-dextrin or
cyclooctaamylose, and 1 year later, Cramer, his PhD student, introduced the
cyclodextrin- based nomenclature. From 1950 onward, this terminology was increasingly used although the nomenclature of cyclodextrins remained a subject of debate
until the end of the 1990s.
N. Morin-Crini et al.