Extraction of guayule resin

1 . A method of extracting Parthenium argentatum resin constituents from Parthenium argentatum resin, the method comprising:

(a) dissolving the Parthenium argentatum resin in a nonpolar solvent to obtain a nonpolar resin solution and a first precipitate;

(b) separating the first precipitate from the nonpolar resin solution;

(c) adding a polar solvent to the nonpolar resin solution to obtain a mixed polarity resin solution and a second precipitate;

(d) separating the second precipitate from the mixed polarity resin solution to obtain a mixed solvent filtrate;

(e) adding water to the mixed solvent filtrate to obtain a two-phase system comprising an aqueous polar liquid fraction and a nonpolar liquid fraction;

(f) separating the aqueous polar liquid fraction and the nonpolar liquid fraction;

(g) recovering a first solids mixture by desolventizing the polar liquid fraction;

(h) recovering a second solids mixture by desolventizing the nonpolar liquid fraction; and

performing continuous countercurrent extraction, wherein the nonpolar resin solution flows as a nonpolar solution stream countercurrent to a polar solution stream comprising a mixture of water and the polar solvent, and wherein the nonpolar solution stream becomes progressively enriched in guayulins, the polar solution stream becomes progressively enriched in argentatins, and the second precipitate is continuously removed by centrifugation.

2 . The method of claim 1 , wherein the nonpolar solvent is selected from the group consisting of hexanes, pentanes, petroleum ether, toluene, cyclohexane, and mixtures thereof.

3 . The method of claim 1 , wherein the nonpolar solvent is at least one of toluene and cyclohexane.

4 . The method of claim 1 , wherein the polar solvent is selected from the group consisting of methanol, ethanol, isopropanol, acetone, and mixtures thereof.

5 . The method of claim 1 , wherein the first precipitate comprises lignocellulosic substances and the second precipitate comprises coagulated isoprene rubber particles.

6 . The method of claim 1 , wherein the first solids mixture comprises argentatins.

7 . The method of claim 1 , wherein the second solids mixture comprises guayulins.

8 . The method of claim 1 , wherein the step of dissolving the Parthenium argentatum resin in a nonpolar solvent comprises combining a w/w ratio of Parthenium argentatum resin to nonpolar solvent of from about 1:1 to about 1:2.

9 . The method of claim 1 , wherein the step of dissolving the Parthenium argentatum resin in a nonpolar solvent further comprises heating up to a temperature below the boiling point of the nonpolar solvent to accelerate dissolution.

10 . The method of claim 1 , wherein the step of adding the polar solvent to the nonpolar resin solution comprises mixing a w/w ratio of the polar solvent to the nonpolar resin solution of from about 0.5:1 to about 2:1.

11 . A method of extracting Parthenium argentatum resin constituents from Parthenium argentatum resin, the method comprising:

(a) dissolving the Parthenium argentatum resin in a nonpolar solvent to obtain a nonpolar resin solution and a precipitate;

(b) separating the precipitate from the nonpolar resin solution;

(c) adding water or an aqueous polar solvent to the nonpolar resin solution to obtain a two-phase system comprising an aqueous polar liquid fraction and a nonpolar liquid fraction;

(d) separating the aqueous polar liquid fraction and the nonpolar liquid fraction;

(e) recovering a first solids mixture by desolventizing the polar liquid fraction;

(f) recovering a second solids mixture by desolventizing the nonpolar liquid fraction; and

performing continuous countercurrent extraction, wherein the nonpolar resin solution flows as a nonpolar solution stream countercurrent to a polar solution stream comprising a mixture of water and the polar solvent, and wherein the nonpolar solution stream becomes progressively enriched in natural polyisoprene rubber and the polar solution stream becomes progressively enriched in argentatins.

12 . The method of claim 11 , wherein the nonpolar solvent is selected from the group consisting of hexanes, pentanes, petroleum ether, toluene, cyclohexane, and mixtures thereof.

13 . The method of claim 11 , wherein the nonpolar solvent comprises at least one of toluene and cyclohexane.

14 . The method of claim 11 , wherein the aqueous polar solvent comprises a mixture of water and a polar solvent selected from the group consisting of methanol, ethanol, isopropanol, acetone, and mixtures thereof.

15 . The method of claims claim 11 , wherein the precipitate comprises lignocellulosic substances in a form of solid particles.

16 . The method of claims claim 11 , wherein the first solids mixture comprises argentatins.

17 . The method of claims claim 11 , wherein the second solids mixture comprises low MW isoprene rubber.

18 . The method of claim 11 , further comprising: separating lignocellulosic substances from the Parthenium argentatum resin, by the steps comprising:

dissolving the Parthenium argentatum resin in at least one nonpolar solvent to form a nonpolar resin solution further comprising precipitated lignocellulosic substances;

separating the precipitated lignocellulosic substances from the nonpolar resin solution; and

optionally washing the precipitated lignocellulosic substances with aliquots of the nonpolar solvent.

19 . The method of claim 18 , wherein the nonpolar solvent is selected from the group consisting of hexanes, pentanes, petroleum ether, toluene, cyclohexane and mixtures thereof.

20 . A method of separating natural polyisoprene rubber from Parthenium argentatum resin, the method comprising:

(a) dissolving the Parthenium argentatum resin in a nonpolar solvent to form a nonpolar resin solution further comprising a first precipitate;

(b) separating the first precipitate from the nonpolar resin solution;

(c) adding a polar solvent to the nonpolar resin solution to precipitate the natural polyisoprene rubber in the form of coagulated particles; and

(d) recovering the precipitated natural polyisoprene rubber from the nonpolar resin solution; and

performing continuous countercurrent extraction, wherein the nonpolar resin solution flows as a nonpolar solution stream countercurrent to a polar solution stream comprising a mixture of water and the polar solvent, and wherein the nonpolar solution stream becomes progressively enriched in natural polyisoprene rubber and the polar solution stream becomes progressively enriched in argentatins.

21 . The method of claim 20 , wherein the nonpolar solvent is selected from the group consisting of hexanes, pentanes, petroleum ether, toluene, cyclohexane, and mixtures thereof.

22 . The method of claim 20 , wherein the polar solvent is selected from the group consisting of methanol, ethanol, isopropanol, acetone, and mixtures thereof.

23 . A method of separating a mixture of triterpenes from Parthenium argentatum resin, the method comprising:

(a) dissolving the Parthenium argentatum resin in a nonpolar solvent to form a nonpolar resin solution further comprising a first precipitate;

(b) separating the first precipitate from the nonpolar resin solution;

(c) adding a polar solvent to the nonpolar resin solution to form a mixed polarity resin solution further comprising a second precipitate;

(d) separating the second precipitate from the mixed polarity resin solution;

(e) adding water to the mixed polarity resin solution to form separable aqueous polar and nonpolar liquid fractions;

(f) separating the aqueous polar liquid fraction from the nonpolar liquid fraction; and

(g) recovering the mixture of triterpenes by desolventizing the aqueous polar liquid fraction.

24 . The method of claim 23 , wherein the nonpolar solvent is selected from the group consisting of hexanes, pentanes, petroleum ether, toluene, cyclohexane, and mixtures thereof.

25 . The method of claim 23 , wherein the polar solvent is selected from the group consisting of methanol, ethanol, isopropanol, acetone, and mixtures thereof.

26 . A method of isolating a mixture of terpenes and sesquiterpenes from Parthenium argentatum resin, the method comprising:

(a) dissolving the Parthenium argentatum resin in a nonpolar solvent to form a nonpolar resin solution further comprising a first precipitate;

(b) separating the first precipitate from the nonpolar resin solution;

(c) adding a polar solvent to the nonpolar resin solution to provide a mixed polarity resin solution further comprising a second precipitate;

(d) separating the second precipitate from the mixed polarity resin solution;

(e) adding water to the mixed polarity resin solution to form separable aqueous polar and nonpolar liquid fractions;

(f) separating the nonpolar liquid fraction from the aqueous polar liquid fraction; and

(g) recovering the mixture comprising terpenes and sesquiterpenes by evaporating the nonpolar liquid fraction.

27 . The method of claim 26 , wherein the nonpolar solvent is selected from the group consisting of hexanes, pentanes, petroleum ether, toluene, cyclohexane, and mixtures thereof.

28 . The method of claim 26 , wherein the polar solvent is selected from the group consisting of methanol, ethanol, isopropanol, acetone, and mixtures thereof.

29 . A method of separating natural polyisoprene rubber from Parthenium argentatum resin, the method comprising:

(a) dissolving the Parthenium argentatum resin in a nonpolar solvent to form a nonpolar resin solution further comprising a first precipitate;

(b) separating the first precipitate from the nonpolar resin solution;

(c) adding a polar solvent to the nonpolar resin solution to precipitate the natural polyisoprene rubber in the form of coagulated particles; and

(d) recovering the precipitated natural polyisoprene rubber from the nonpolar resin solution; and

performing continuous countercurrent extraction, wherein the nonpolar resin solution flows as a nonpolar solution stream countercurrent to a polar solution stream comprising a mixture of water and the polar solvent, and wherein the nonpolar solution stream becomes progressively enriched in natural polyisoprene rubber and the polar solution stream becomes progressively enriched in argentatins.

30 . The method of claim 29 , wherein the nonpolar solution stream also becomes progressively enriched in natural polyisoprene rubber.