Morphology of galactomannans: An X-ray structure analysis of guaran

Rengaswami Chandrasekaran; Akella Radha; Kenji Okuyama

doi:10.1016/S0008-6215(97)00274-7

Morphology of galactomannans: An X-ray structure analysis of guaran

Rengaswami Chandrasekaran, Akella Radha, Kenji Okuyama

Research output: Contribution to journal › Article › peer-review

21 Scopus citations

Abstract

The three-dimensional structure of a galactomannan has been determined by careful analysis of the X-ray data obtained from polycrystalline and well oriented fibers of guaran. The polymer forms a flat 2-fold helix of pitch 10.38 Å. The galactosyl side-chain hydrogen bonds to the mannan backbone intramolecularly and provides structural stability. Four helices are packed in an orthorhombic unit cell of dimensions a = 9.26, b = 30.84 and c (fiber axis) = 10.38 Å according to space group symmetry 1222. Each chemical repeat consisting of 1.0 mannosyl and 0.6 galactosyl units is associated with two structured water molecules which are responsible for the formation and stability of sheets of guaran helices in the crystalline lattice. The crystallographic R-value is 0.185 for the best model. The guaran molecular structure and packing arrangement presented here are readily adoptable to the entire galactomannan family.

Original language	English (US)
Pages (from-to)	243-255
Number of pages	13
Journal	Carbohydrate Research
Volume	306
Issue number	1-2
DOIs	https://doi.org/10.1016/S0008-6215(97)00274-7
State	Published - Jan 1998

Keywords

Galactomannan
Guaran
Three-dimensional structure
X-ray diffraction

ASJC Scopus subject areas

Analytical Chemistry
Biochemistry
Organic Chemistry

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10.1016/S0008-6215(97)00274-7

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title = "Morphology of galactomannans: An X-ray structure analysis of guaran",

abstract = "The three-dimensional structure of a galactomannan has been determined by careful analysis of the X-ray data obtained from polycrystalline and well oriented fibers of guaran. The polymer forms a flat 2-fold helix of pitch 10.38 {\AA}. The galactosyl side-chain hydrogen bonds to the mannan backbone intramolecularly and provides structural stability. Four helices are packed in an orthorhombic unit cell of dimensions a = 9.26, b = 30.84 and c (fiber axis) = 10.38 {\AA} according to space group symmetry 1222. Each chemical repeat consisting of 1.0 mannosyl and 0.6 galactosyl units is associated with two structured water molecules which are responsible for the formation and stability of sheets of guaran helices in the crystalline lattice. The crystallographic R-value is 0.185 for the best model. The guaran molecular structure and packing arrangement presented here are readily adoptable to the entire galactomannan family.",

keywords = "Galactomannan, Guaran, Three-dimensional structure, X-ray diffraction",

author = "Rengaswami Chandrasekaran and Akella Radha and Kenji Okuyama",

note = "Funding Information: This research was supported in part by the Industrial Consortium of the Whistler Center for Carbohydrate Research, and Nutrasweet Kelco, a Unit of Monsanto.",

year = "1998",

month = jan,

doi = "10.1016/S0008-6215(97)00274-7",

language = "English (US)",

volume = "306",

pages = "243--255",

journal = "Carbohydrate Research",

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T2 - An X-ray structure analysis of guaran

AU - Chandrasekaran, Rengaswami

AU - Radha, Akella

AU - Okuyama, Kenji

N1 - Funding Information: This research was supported in part by the Industrial Consortium of the Whistler Center for Carbohydrate Research, and Nutrasweet Kelco, a Unit of Monsanto.

PY - 1998/1

Y1 - 1998/1

N2 - The three-dimensional structure of a galactomannan has been determined by careful analysis of the X-ray data obtained from polycrystalline and well oriented fibers of guaran. The polymer forms a flat 2-fold helix of pitch 10.38 Å. The galactosyl side-chain hydrogen bonds to the mannan backbone intramolecularly and provides structural stability. Four helices are packed in an orthorhombic unit cell of dimensions a = 9.26, b = 30.84 and c (fiber axis) = 10.38 Å according to space group symmetry 1222. Each chemical repeat consisting of 1.0 mannosyl and 0.6 galactosyl units is associated with two structured water molecules which are responsible for the formation and stability of sheets of guaran helices in the crystalline lattice. The crystallographic R-value is 0.185 for the best model. The guaran molecular structure and packing arrangement presented here are readily adoptable to the entire galactomannan family.

AB - The three-dimensional structure of a galactomannan has been determined by careful analysis of the X-ray data obtained from polycrystalline and well oriented fibers of guaran. The polymer forms a flat 2-fold helix of pitch 10.38 Å. The galactosyl side-chain hydrogen bonds to the mannan backbone intramolecularly and provides structural stability. Four helices are packed in an orthorhombic unit cell of dimensions a = 9.26, b = 30.84 and c (fiber axis) = 10.38 Å according to space group symmetry 1222. Each chemical repeat consisting of 1.0 mannosyl and 0.6 galactosyl units is associated with two structured water molecules which are responsible for the formation and stability of sheets of guaran helices in the crystalline lattice. The crystallographic R-value is 0.185 for the best model. The guaran molecular structure and packing arrangement presented here are readily adoptable to the entire galactomannan family.

KW - Galactomannan

KW - Guaran

KW - Three-dimensional structure

KW - X-ray diffraction

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U2 - 10.1016/S0008-6215(97)00274-7

DO - 10.1016/S0008-6215(97)00274-7

M3 - Article

AN - SCOPUS:0031798692

SN - 0008-6215

VL - 306

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EP - 255

JO - Carbohydrate Research

JF - Carbohydrate Research

IS - 1-2

ER -

Morphology of galactomannans: An X-ray structure analysis of guaran

Abstract

Keywords

ASJC Scopus subject areas

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