Humic acid derivatives and methods of preparation and use
View Patent ↗Disclosed are antioxidative natural compounds, their salts, chelates and cleavage derivatives that exhibit a superior combination of properties. The compounds can be used for a variety of purposes, including the stabilization of polymers. The compounds can be prepared by substantially cleaving a humic acid of formula I followed by esterification to provide at least one antioxidant compounds of formula V, formula VI, formula VII, formula VIII, salts thereof, or chelates thereof.
1. A stabilizing compound comprising a compound of formula V:
wherein
R 11 is —N(R 111 )(R 112 ), wherein R 111 is C-acetamido or substituted C-acetamido; R 112 is hydrogen, —(C 1 -C 20 )alkyl, substituted —(C 1 -C 20 )alkyl, —(C═O)—(C 3 -C 19 )alkyl, or substituted -(C═O)—(C 3 -C 19 )alkyl;
R 12 , R 141 , R 142 , R 143 , and R 144 are independently hydrogen, —(C 1 -C 20 )alkyl, or substituted —(C 1 -C 20 )alkyl;
R 13 is hydrogen, —(C 1 -C 20 )alkyl, substituted —(C 1 -C 20 )alkyl, —(C═O)—(C 3 -C 19 )alkyl, or substituted —(C═O)—(C 3 -C 19 )alkyl;
R 16 is a hydrogen, glucuronate or substituted glucuronate;
R 151 , R 152 , R 153 , R 154 , R 155 , and R 156 are independently hydrogen, —(C═O)—(C 3 -C 19 )alkyl, or substituted —(C═O)—(C 3 -C 19 )alkyl,
wherein at least one of R 141 , R 142 , R 143 , R 144 , R 151 , R 152 , R 153 , R 154 , R 155 , and R 156 is not hydrogen;
a salt, chelate, or combination thereof.
2. The compound of claim 1 , wherein the compound is a salt thereof.
3. The compound of claim 1 , wherein R 141 , R 142 , R 143 , and R 144 are independently hydrogen or —(C 4 -C 20 )alkyl.
4. The compound of claim 1 , wherein R 151 , R 152 , R 153 , R 154 , R 155 , and R 156 are independently hydrogen or —(C═O)—(C 3 -C 19 )alkyl.
5. The compound of claim 1 , wherein the compound is a lithium salt, sodium salt, ammonium salt, potassium salt, calcium salt, barium salt, magnesium salt, manganese salt, zinc salt, aluminum salt, iron salt, or a combination thereof.
6. The compound of claim 1 , wherein the compound is a polyvalent cation chelate.
7. The compound of claim 1 , wherein the compound is a calcium chelate, magnesium chelate, iron chelate, or zinc chelate or combination thereof.
8. A method of preparing a polymer stabilizing mixture of compounds, the method comprising:
substantially hydrolyzing a humic acid to form a mixture of compounds according to formula V a salt or chelate thereof:
wherein:
R 11 is —N(R 111 )(R 112 ), wherein R 111 is C-acetamido or substituted C-acetamido;
R 112 is hydrogen, —(C 1 -C 20 )alkyl, substituted —(C 1 —C 20 )alkyl, —(C═O)—(C 3 -C 19 alkyl, or substituted —(C═O)—(C 3 -C 19 )alkyl;
R 12 , R 141 , R 142 , R 143 and R 144 are independently hydrogen, -(C 4 —C 20 )alkyl, or substituted —(C 4 -C 20 alkyl;
R 13 is hydrogen, —(C 1 -C 20 alkyl, substituted —(C 1 -C 20 )alkyl, —(C═O)—(C 3 —C 19 )alkyl, or substituted —(C═O)—(C 3 -C 19 )alkyl;
R 16 is hydrogen, glucuronate, or substituted glucuronate;
R 151 , R 152 , R 153 , R 154 , R 155 , and R 156 are independently hydrogen, —(C═O)—(C 3 -C 19 )alkyl, or substituted —(C═O)—(C 3 -C 19 )alkyl;
R 141 , R 142 , R 143 , R 144 , R 151 , R 152 , R 153 , R 154 , R 155 , and R 156 are hydrogen; and
esterifying at least one functional group of the mixture of compounds to give a polymer stabilizing mixture of compounds.
9. The method of claim 8 , further comprising forming a chelate of the compound of the polymer stabilizing mixture with a calcium cation, magnesium cation, zinc cation, iron cation, or combinations thereof.
10. The method of claim 8 , further comprising forming a salt of the compound of the polymer stabilizing mixture to form a lithium salt, sodium salt, ammonium salt, potassium salt, calcium salt, barium salt, magnesium salt, manganese salt, zinc salt, aluminum salt, iron salt, or a combination thereof.
11. The method of claim 8 , further comprising purifying the compound of the polymer stabilizing mixture.
12. The method of claim 8 , further comprising isolating the compound of formula V wherein at least one of R 141 , R 142 , R 143 , R 144 , R 151 , R 152 , R 153 , R 154 , R 155 , and R 156 is not hydrogen; at least one of R 21 , R 22 , R 23 , R 24 , R 25 , R 26 , and R 27 is not hydrogen; at least one of R 31 , R 32 , R 33 , R 34 , R 35 , and R 36 is not hydrogen; and at least one of R 41 , R 42 , R 43 , and R 44 is not hydrogen.
13. The method of claim 8 , wherein the humic acid comprises at least one compound of formula I:
salt, or chelate thereof, wherein
R 11 is —N(R 111 )(R 112 ), wherein R 111 is C-acetamido or substituted C-acetamido; R 112 is hydrogen, —(C 1 —C 20 )alkyl, substituted —(C 1 -C 20 )alkyl, —(C═O)—(C 3 -C 19 )alkyl, or substituted —(C═O)—(C 3 —C 19 )alkyl;
R 12 is hydrogen, —(C 1 -C 20 )alkyl, or substituted —(C 1 -C 20 )alkyl;
R 13 is hydrogen, —(C 1 -C 20 )alkyl, substituted —(C 1 -C 20 )alkyl, —(C═O)—(C 3 -C 19 )alkyl, or substituted —(C═O)—(C 3 -C 19 )alkyl; and
R 16 is a hydrogen, glucuronate or substituted glucuronate.
14. The method of claim 8 , wherein the hydrolyzing comprises hydrolyzing in the presence of an alkaline solution.
15. The method of claim 14 , wherein the alkaline solution is aqueous lithium hydroxide, aqueous sodium hydroxide, aqueous potassium hydroxide, or combination thereof.
16. The method of claim 8 , wherein the hydrolyzing comprises hydrolyzing at a pH of 8.5-13.