Enzymatically polymerized gelling dextrans

Patent metadata

Field	Value
Publication number	US-2018355072-A1
Application number	US-201816111514-A
Country	US
Kind code	A1
Filing date	Aug 24, 2018
Priority date	Nov 5, 2014
Publication date	Dec 13, 2018
Grant date	—

Abstract

Compositions are disclosed herein comprising dextran that comprises (i) 87-93 wt % glucose linked at positions 1 and 6; (ii) 0.1-1.2 wt % glucose linked at positions 1 and 3; (iii) 0.1-0.7 wt % glucose linked at positions 1 and 4; (iv) 7.7-8.6 wt % glucose linked at positions 1, 3 and 6; and (v) about 0.4-1.7 wt % glucose linked at (a) positions 1, 2 and 6, or (b) positions 1, 4 and 6. Aqueous forms of this composition have enhanced viscosity profiles. Further disclosed are methods of using compositions comprising dextran, such as increasing the viscosity of an aqueous composition. Enzymatic reactions for producing dextran are also disclosed.

First claim

What is claimed is:

1 . A composition comprising dextran, wherein said dextran comprises:
(i) about 87-93 wt % glucose linked at positions 1 and 6; (ii) about 0.1-1.2 wt % glucose linked at positions 1 and 3; (iii) about 0.1-0.7 wt % glucose linked at positions 1 and 4; (iv) about 7.7-8.6 wt % glucose linked at positions 1, 3 and 6; and (v) about 0.4-1.7 wt % glucose linked at:
(a) positions 1, 2 and 6, or
(b) positions 1, 4 and 6;
wherein the weight-average molecular weight (Mw) of said dextran is about 50-200 million Daltons, the z-average radius of gyration of said dextran is about 200-280 nm, and the dextran optionally is not a product of a Leuconostoc mesenteroides glucosyltransferase enzyme.

2 . The composition of claim 1 , wherein the dextran comprises:
(i) about 89.5-90.5 wt % glucose linked at positions 1 and 6; (ii) about 0.4-0.9 wt % glucose linked at positions 1 and 3; (iii) about 0.3-0.5 wt % glucose linked at positions 1 and 4; (iv) about 8.0-8.3 wt % glucose linked at positions 1, 3 and 6; and (v) about 0.7-1.4 wt % glucose linked at:
(a) positions 1, 2 and 6, or
(b) positions 1, 4 and 6.

3 . The composition of claim 1 , wherein the dextran comprises chains linked together within a branching structure, wherein said chains are similar in length and comprise substantially alpha-1,6-glucosidic linkages.

4 . The composition of claim 3 , wherein the average length of the chains is about 10-50 monomeric units.

5 . The composition of claim 1 , wherein the dextran is a product of a glucosyltransferase enzyme comprising an amino acid sequence that is at least 90% identical to SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:5, SEQ ID NO:9, SEQ ID NO:13, or SEQ ID NO:17.

6 . The composition of claim 1 , wherein the composition is an aqueous composition having a viscosity of at least about 25 cPs.

7 . The composition of claim 1 , wherein the Mw of the dextran is about 80-120 million Daltons.

8 . The composition of claim 1 , wherein the z-average radius of gyration of said dextran is about 230-250 nm.

9 . The composition of claim 1 , wherein the composition is in the form of a food product, personal care product, pharmaceutical product, household product, or industrial product.

10 . The composition of claim 9 , wherein the composition is in the form of a confectionery.

11 . A method for increasing the viscosity of an aqueous composition, the method comprising:
contacting dextran according to claim 1 with the aqueous composition, wherein the viscosity of the aqueous composition is increased by said dextran compared to the viscosity of the aqueous composition before the contacting step.

12 . A method of treating a material, said method comprising:
contacting a material with an aqueous composition comprising dextran according to claim 1 .

13 . An enzymatic reaction comprising water, sucrose and a glucosyltransferase enzyme comprising an amino acid sequence that is at least 90% identical to SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:5, SEQ ID NO:9, SEQ ID NO:13, or SEQ ID NO:17,
wherein the glucosyltransferase enzyme synthesizes dextran according to claim 1 .

14 . A method for producing dextran, said method comprising:
a) contacting at least water, sucrose, and a glucosyltransferase enzyme comprising an amino acid sequence that is at least 90% identical to SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:5, SEQ ID NO:9, SEQ ID NO:13, or SEQ ID NO:17,
whereby dextran according to claim 1 is produced; and
b) optionally, isolating the dextran produced in step (a).

15 . The method of claim 14 , wherein the viscosity of the dextran produced in the method is increased by decreasing the amount of sucrose in step (a).

Assignees

• Du Pont

Inventors

• Nambiar Rakesh
• Guan Rong
• Cheng Qiong
• Dicosimo Robert
• Paullin Jayme L
• Liang Yuanfeng
• Powley Charles R
• Brun Yefim

Classifications

• C08B37/0021 Primary

  Dextran, i.e. (alpha-1,4)-D-glucan; Derivatives thereof, e.g. Sephadex, i.e. crosslinked dextran · CPC title

• C11D3/222

  Natural or synthetic polysaccharides, e.g. cellulose, starch, gum, alginic acid or cyclodextrin · CPC title

• C12P19/08

  Dextran · CPC title

• C08L5/02

  Dextran; Derivatives thereof · CPC title

• C12P19/18

  produced by the action of a glycosyl transferase, e.g. alpha-, beta- or gamma-cyclodextrins · CPC title