Single helical structure of curdlan triacetate

Okuyama, Kenji; Obata, Yayoi; Noguchi, Keiichi; Kusaba, Takasi; Ito, Yasushi; Ohno, Shigeru

doi:10.1002/(sici)1097-0282(199605)38:5<557::aid-bip1>3.0.co;2-r

Cited by 31 publications

(32 citation statements)

References 22 publications

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“…The high temperature gels were also much more resistant to hydrolysis by 1.3-~-D-glucanases and by acid treatment and failed to melt on further heating. This alteration in properties was ascribed to the formation of a pseudocrystalline form with greatly reduced hydration of the curdlan following high temperature treatment (Kanzawa et al, 1989 yielded a single helical structure in which there was one molecule of water per glucose residue (Okuyama et al, 1996). Although it has been less studied than curdlan, the linear l,3-Cl-D-glucan mutan produced by Streptococcus mutans also exhibits crystalline structure (Ogawa et al, 1981) Gellan has proved to be one of the most interesting recent microbial polysaccharide introductions.…”

Section: Polysaccharide Properties and Applicationssupporting

confidence: 75%

Microbial Polysaccharide Products

Sutherland

1999

Biotechnology and Genetic Engineering Reviews

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Section: Polysaccharide Properties and Applicationssupporting

confidence: 75%

Microbial Polysaccharide Products

Sutherland

1999

Biotechnology and Genetic Engineering Reviews

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“…Furthermore, h for CdTPC in THF is close to that for single helical crystal of curdlan [30] and curdlan acetate [31], indicating that the CdTPC main chain has tightly wound single helical structure. On the one hand, CdTPC in MIBK has locally extended but rather flexible coil-like main chain, suggesting that the intramolecular H-bonds in MIBK should be less than that in THF and furthermore the H-bonding solvent molecules may extend the main chain of CdTPC as seen for ATPC [13].…”

Section: Dimensional and Hydrodynamic Propertiesmentioning

confidence: 57%

Rigid helical conformation of curdlan tris(phenylcarbamate) in solution

Ochiai

Terao

Nakamura

et al. 2012

Polymer

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Light and small-angle X-ray scattering and viscosity measurements were made for four curdlan tris(phenylcarbamate) (CdTPC) samples having quite narrow dispersity indices (DI) and ranging in the molecular weight between 6  10 4 and 2  10 6 , to determine weightaverage molecular weights M w , radii of gyration , particle scattering functions P(q), and intrinsic viscosities [] in tetrahydrofuran (THF) and 4-methyl-2-pentanone (MIBK). Size exclusion chromatography equipped with light scattering and/or viscosity detectors was performed for some broad DI samples in THF also to determine and [] as a function of M w. The solution data were analyzed in terms of the wormlike-chain model to estimate the Kuhn segment length of 57 nm in THF and 17 nm in MIBK and the helix pitch per residue h of 0.39 nm in THF and 0.51 nm in MIBK. Since the former h value is almost equivalent to that for single helical curdlan and its acetate derivative in crystal, it is reasonably suggested that the local conformation of CdTPC in THF is close to the tightly wound helix stabilized by the intramolecular hydrogen bonding, which was detected from the solution IR spectra.

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“…2) and remaining OH groups in the skeletal unit can take a cellulosic parallel chain structure using the considerable skeletal interaction, while curdlan triacetate that has no hydrogen‐bonding capacity resulted in a crystal structure like curdlan I with a hexagonal packing of single helical glucan. [ 42 ] CrdC having the longer alkyl groups could assist to take the cellulosic parallel chain structure more effectively using an interdigitated alkyl‐chain packing with van der Waals force. [ 43 ] The alkyl chain separation should control distance between the glucan chains, which might correspond to the d values of halo‐2 signals as shown in Figure 6.…”

Section: Resultsmentioning
confidence: 99%

Synthesis of thermoplastic curdlan alkyl carbamates having hydrogen bonding ability
Kawashima
¹
,
Ozawa
²
,
Kijima
³

2020
Journal of Polymer Science
4
2
3
0
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Rigid and little moldable curdlan, a linear β‐1,3‐glucan having intra‐ and interchain hydrogen bonds, was reacted with several alkyl isocyanates, which gave thermoplastic curdlan alkyl carbamates (CrdC) with degree of substitution about 2. The alkyl carbamation at hydroxy groups in the glucan skeleton effectively broke the interchain hydrogen bonds of curdlan and increased flexibility of CrdC, while the newly formed carbamate moieties could moderately keep the hydrogen bonding ability in CrdC. Elongating the alkyl groups in the carbamate side chains increased solubility in organic solvents and thermoplasticity of CrdC, which enabled to make homogeneous and free‐standing films by both methods of solution‐casting and hot‐pressing.

~~show abstract~~

Single helical structure of curdlan triacetate

Cited by 31 publications

References 22 publications

Microbial Polysaccharide Products

Microbial Polysaccharide Products

Rigid helical conformation of curdlan tris(phenylcarbamate) in solution

Synthesis of thermoplastic curdlan alkyl carbamates having hydrogen bonding ability

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