PREPARATION OF POLY ALPHA-1,3-GLUCAN ESTERS USING CYCLIC ORGANIC ANHYDRIDES

1 . A composition comprising a poly alpha-1,3-glucan ester compound represented by the structure:

wherein

(i) n is at least 6;

(ii) each R is independently an —H or a first group comprising —CO—C x —COON, wherein the —C x — portion of said first group comprises a chain of 2 to 6 carbon atoms; and

(iii) the compound has a degree of substitution with the first group of about 0.001 to about 3.0.

2 . The composition of claim 1 , wherein the —C x — portion of said first group comprises only CH 2 groups.

3 . The composition of claim 2 , wherein said first group comprises:

—CO—CH 2 —CH 2 —COON,

—CO—CH 2 —CH 2 —CH 2 —COON,

—CO—CH 2 —CH 2 —CH 2 —CH 2 —COON,

—CO—CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —COON, or

—CO—CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —COON.

4 . The composition of claim 1 , wherein the —C x — portion of said first group comprises:

(i) at least one double-bond in said carbon atom chain, and/or

(ii) at least one branch comprising an organic group.

5 . The composition of claim 4 , wherein the —C x — portion of said first group comprises at least one double-bond in said carbon atom chain.

6 . The composition of claim 5 , wherein said first group comprises:

—CO—CH═CH—COOH.

7 . The composition of claim 4 , wherein the —C x — portion of said first group comprises at least one branch comprising an organic group.

8 . The composition of claim 7 , wherein said first group comprises:

9 . A method of producing a poly alpha-1,3-glucan ester compound, the method comprising:

(a) contacting poly alpha-1,3-glucan in a reaction with a cyclic organic anhydride, thereby producing a poly alpha-1,3-glucan ester compound represented by the structure:

wherein

(i) n is at least 6;

(ii) each R is independently an —H or a first group comprising —CO—C x —COON, wherein the —C x — portion of said first group comprises a chain of 2 to 6 carbon atoms; and

(iii) the compound has a degree of substitution with the first group of about 0.001 to about 3.0;

and

(b) optionally, isolating the poly alpha-1,3-glucan ester compound produced in step (a).

10 . The method of claim 9 , wherein the reaction initially consists of the poly alpha-1,3-glucan and cyclic organic anhydride, wherein the cyclic organic anhydride is melted.

11 . The method of claim 9 , wherein the reaction does not comprise an organic solvent.

12 . The method of claim 9 , wherein the reaction comprises aqueous conditions.

13 . The method of claim 12 , wherein a basic pH is maintained during the reaction.

14 . The method of claim 9 , wherein the poly alpha-1,3-glucan and poly alpha-1,3-glucan ester are each in a solid form during the reaction.

15 . The method of claim 9 , wherein the reaction does not comprise a catalyst.