# Patent

## Title
Biological buffers with wide buffering ranges

## Abstract

Amines and amine derivatives that improve the buffering range, and/or reduce the chelation and other negative interactions of the buffer and the system to be buffered. The reaction of amines or polyamines with various molecules to form polyamines with differing pKa's will extend the buffering range, derivatives that result in polyamines that have the same pKa yields a greater buffering capacity. Derivatives that result in zwitterionic buffers improve yield by allowing a greater range of stability.

## Background
This application is a continuation in part of application 12/899,361 filed Oct. 6, 2010, now U.S. Pat. No. 8,334,402 which was a continuation in part of application Ser. No. 12/751,053 filed Mar. 31, 2010, now U.S. Pat. No. 8,034,951 on Oct. 11, 2011, which was a continuation in part of application Ser. No. 12/606,762 filed Oct. 27, 2009, now U.S Pat. No, 7,939,659 issued May 10, 2011, which was a continuation in part of application Ser. No. 12/437,749 filed May 8, 2009, now U.S. Pat. No. 7,851,652 issued Dec. 14, 2010, which was a continuation in part of application Ser. No. 12/151,899 filed May 9, 2008, now U.S. Pat. 7,635,791 issued Dec. 22, 2009, which was a non-provisional of 61/124,586 filed Apr. 17, 2008. This application also claims priority from Provisional Patent Application No. 61/391,227 filed Oct. 8, 2010, 61,393,706 filed Oct. 15, 2010 and 61/505,613 filed Jul. 8, 2011.
Applications Ser. Nos. 12/899,361, 12/751,053, 12/606,762, 12/437,749, 12/151,899, 61/124,586, 61391,227, 61/393,706 and 61/505,613 are hereby incorporated by reference. Provisional applications 61/135,058 and 61/249,090 are also hereby incorporated by reference.


BACKGROUND
1. Field of the Invention
The present invention relates generally to the field of amines and more particularly to a classes of amines used as buffers in biological systems.
2. Description of the Problem Solved by the Invention
Amines are very useful compounds in the buffering of biological systems. Each class of amine has various limitations which require choosing an amine based on multiple factors to select the best amine. For example, pH buffering range is typically most important, but issues of chelation, and pH range stability, and solubility also come into play. Typically, a suboptimal buffer will result in yields that are well below the potential yield. The invention disclosed improves the yields in fermentation and purification, and improves shelf stability of proteins and amino acids.
SUMMARY OF THE INVENTION
The present invention relates to amines and amine derivatives that improve the buffering range, and/or reduce the chelation and other negative interactions of the buffer and the system to be buffered. The reaction of amines or polyamines with various molecules to form polyamines with differing pKa's will extend the buffering range, derivatives that result in polyamines that have the same pKa yields a greater buffering capacity. Derivatives that result in zwitterionic buffers improve yield by allowing a greater range of stability.



DESCRIPTION OF THE FIGURES
Attention is now directed to the following figures that describe embodiments of the present invention:
FIG. 1 shows the derivation of polyamines and zwitterionic buffers from tromethamine.
FIG. 2 shows the derivation of zwitterionic buffers and polyamines from aminomethylpropanol.
FIG. 3 shows the reaction of 2-methyl-2-nitro-1-propanol with acrylonitrile and its derivatives.
FIG. 4 shows the reaction of 2-nitro-2-ethyl-1,3-propanediol with acrylonitrile and its derivatives where x,y,and n are all integers where x and y are chosen independently, such that x+y=n and n is greater than zero.
FIG. 5 shows the reaction of 2-nitro-2-methyl-1,3-propanediol with acrylonitrile and its derivatives where x,y,and n are all integers where x and y are chosen independently, such that x+y=n and n is greater than zero.
FIG. 6 shows the reaction of tris(hydroxymethyl)nitromethane with acrylonitrile and its derivatives where x,y, z, and n are all integers where x, y and z are chosen independently, such that x+y+z=n and n is greater than zero.
FIG. 7 shows the reaction of 2-nitro-1,3-propanediol with acrylonitrile and its derivatives where x,y,and n are all integers where x and y are chosen independently, such that x+y=n and n is greater than zero.
FIG. 8 shows the reaction of 2-nitro-1-butanol with acrylonitrile and its derivatives.
FIG. 9 shows alkoxylation of aminomethylpropanol.
FIG. 10A shows the synthesis of a very mild, high foaming, surfactant derived from MCA.
FIG. 10B shows the synthesis of a very mild, high foaming, surfactant derived from SVS.
FIG. 11 shows the synthesis of a series of buffers with 2-nitropropane as the starting material.
FIG. 12 shows the synthesis of a series of buffers with 1-nitropropane as a starting material where n and m are integers where m+n is greater than zero and n is greater than or equal to m.
FIG. 13 shows the synthesis of a series of buffers with nitroethane as a starting material where n and m are integers where m+n is greater than zero and n is greater than or equal to m.
FIG. 14 shows the synthesis of a series of buffers with nitromethane as a starting material where x,y,z and n are integers and x+y+z=n and n is greater than zero.
FIG. 15 shows the synthesis of a series of zwitterionic buffers based on acrylic acids.
FIG. 16 shows the synthesis of a zwitterionic sulfonate based on tromethamine.
FIG. 17 shows the synthesis of a zwitterionic sulfonate based on aminomethylpropanol.
FIG. 18-25 show the synthesis of families of zwitterionic buffers from nitroalcohols.
FIG. 26 shows the synthesis of zwitterionic buffers from morpholine.
FIG. 27 shows the synthesis of zwitterionic buffers from hydroxyethyl piperazine.
FIG. 28 shows the synthesis of zwitterionic buffers from piperazine.
FIG. 29 shows the synthesis of zwitterionic buffers from ethyleneamines.
FIG. 30 shows the synthesis of a zwitterionic buffer with primary, secondary, tertiary, or quaternary amine functionality.
FIGS. 31-33 show the synthesis of mild zwitterionic surfactants from nitroalcohols.
FIG. 34-37 show the synthesis of polyamines from nitroalcohols.
FIG. 38 shows the synthesis of diamines from nitroalcohols and aminoalcohols.
FIG. 39 shows the synthesis of isopropyl amine acrylate buffers and mild surfactants.
FIG. 40 shows the synthesis of zwitterionic buffers from SVS and MCA derived from isopropyl amine as well as mild surfactants and diamines.
FIG. 41 shows the synthesis of a sultaine zwittterionic buffer of isopropyl amine.
FIG. 42 shows the synthesis of zwitterionic buffers from amino alcohols and itaconic acid.
FIG. 43 shows the synthesis of nitro acids from nitroalcohols and itaconic acid.
FIG. 44 shows the synthesis of primary amino zwitterionic buffers from nitro acids.
FIG. 45. shows the synthesis of a family of zwitterionic buffers from itaconic acid and amines.
FIG. 46 shows the synthesis of surfactants from amines and itaconic acid intermediates.
FIG. 47 shows the synthesis of nitroacids from nitroparaffins and itaconic acid.
FIG. 48 shows the synthesis of zwitterionic buffers from nitro acids.
FIG. 49 shows the synthesis of zwitterionic buffers from 4-aminopyridine.
FIG. 50 shows the synthesis zwitterionic buffers from the ketimine conformation of 4-aminopyridine.
FIG. 51 shows the synthesis of zwiiterionic sultaines from 4-aminopyridine.
FIG. 52 shows the synthesis of zwitterionic buffers from taurine.
FIG. 53 shows the synthesis of zwitterionic buffers from homotaurine.
FIG. 54 shows the synthesis of zwitterionic buffers from aspartic acid.
FIG. 55 shows the synthesis of sultaine zwitterionic buffers from sodium bisulfite and epichlorohydrin.
FIG. 56 shows the synthesis of sultaine zwitterionic buffers from sodium bisulfite, epichlorohydrin, and aminoalcohols.
FIG. 57 shows the synthesis of zwitterionic buffers from propane sultone
FIG. 58 shows the synthesis of amidoamine buffers from acrylamide.
FIG. 59 shows the syntheis of amidoamine buffers from methacrylamide.
FIG. 60 shows the synthesis of amidoamine buffers from taurines and diamines.
FIG. 61 shows the synthesis of zwitterionic amidoamine buffers from propone sultone and SVS.
FIG. 62 shows the synthesis of sultaine amidoamine zwitterionic buffers.
FIG. 63 shows the synthesis of a family of coumpounds as zwitterionic buffers and products that are expected to be useful as multiple sclerosis and spinal cord injury therapies.
FIG. 64 shows amide based zwitterionic buffers and products that are expected to be useful as multiple sclerosis and spinal cord injury therapies.
FIG. 65 shows additional zwitterionic buffers based on 4-aminopyridine amides. These products are also expected to be useful as multiple sclerosis and spinal cord injury therapies.
FIG. 66 shows the synthesis of zwitterionic buffers that are also expected to be useful as multiple sclerosis and spinal cord injury therapies. Most of this family has increased hydrogen bonding and is based on the MCA derived zwitterionic buffers disclosed herein.
FIG. 67 shows the synthesis of zwitterionic buffers that are also expected to be useful as multiple sclerosis and spinal cord injury therapies. Most of this family has increased hydrogen bonding and is based on the acrylic acid derived zwitterionic buffers disclosed herein.
FIG. 68 shows the synthesis of zwitterionic buffers that are also expected to be useful as multiple sclerosis and spinal cord injury therapies. Most of this family has increased hydrogen bonding and is based on the methacrylic acid derived zwitterionic buffers disclosed herein.
FIG. 69 shows the synthesis of zwitterionic buffers that are also expected to be useful as multiple sclerosis and spinal cord injury therapies. Derived from ethylene amines.
FIG. 70 shows the synthesis of amidoamine buffers that are stearicly hindered.
FIG. 71 shows the synthesis of amidoamine buffers that are stearicly hindered with extensive hydrogen bonding.
FIG. 72 shows the synthesis of amidoamine buffers.
FIG. 73 shows that any of the amidoamine buffers taught herein, maybe reduced to aminoalcohols or diamines.
FIG. 74 shows the esterification of the zwitterionic buffers.
FIG. 75 shows the esterification, mono- and diesterification of the itaconic acid based zwitterionics.
FIG. 76 shows the synthesis of diacid, tertiary amine, zwitterionic buffers.
FIG. 77 shows the synthesis of amido amines from zwitterionic buffers.
FIG. 78 shows the synthesis of a variety of 4-aminopyridine derivatives that are useful buffers.
FIG. 79 shows the condensation polymerization of the hydroxyl functional zwitterionics.
FIG. 80 clarifies the amidoamine to aminoalcohol or diamine synthesis originally outlined in FIG. 73.
FIG. 81-84 teach the synthesis of sulfonamides from the zwitterionic buffers.
FIG. 85 shows the synthesis of quaternary amine salts from tertiary aminoalcohols.
FIG. 86-87 teach the synthesis of sulfonate esters of the zwitterionic buffers.
FIG. 88-89 teach the synthesis of amino acid, zwitterionic buffers with primary amine functionality.
FIG. 90 expands on the quaternary amine salts shown in FIG. 85.



Several drawings and illustrations have been presented to aid in understanding the invention. The scope of the present invention is not limited to what is shown in the figures.
DETAILED DESCRIPTION OF THE INVENTION
Combining amines with monochloroacetic acid (MCA)or sodium vinyl sulfonate (SVS) results in products are zwitterionic buffers that can buffer in both acidic and basic pH conditions. A limited number amines are currently used for this purpose, such as, tromethamine and ammonia. The reaction of amines, alcohols, and aminoalcohols with acrylonitrile (via the Michaels Addition), followed by reduction results in amines and polyamines that have a broad buffering range. The further derivatization of the amines and polyamines with MCA and SVS yields a further crop of amine buffers with desirable properties. One skilled in the art will recognize that MCA and sodium monochloroacetic acid (SMCA) can be used interchangeably.
The reaction of tromethamine as described above yields the products in FIG. 1. In step 1 in FIG. 1 where the acrylonitrile is added to the amine a branched structure wherein the addition of acrylonitrile results in a tertiary amine is shown. In reality, particularly when n is greater than 1, a mixture of products is obtained that is both tertiary and secondary. For the invention disclosed herein, n may equal any integer greater than zero, including 1. Controlling the reaction temperature, pressure and agitation will allow the mixture to be predominately secondary (such as when m=n) or tertiary amine, m can be any integer less than or equal n. Furthermore, this selection can take place in adding acrylonitrile to the amine that results, allowing a progressively more branched product. It is within the scope of the invention disclosed herein to include these additional types of products and their subsequent derivatives described herein.
With regard to the reaction of the polyamine resulting from the second step in FIG. 1. FIG. 1 shows the addition of only one mole of SVS or MCA, it is known in the art, that a second mole may be added to obtain a product with a second zwitterionic group. Furthermore, in the case where the product has repeated additions of acrylonitrile and reduction to the amines, the branched products may have many more zwitterionic groups. Also, it is to be noted that, while the sulfonates are shown as sodium salts, other salts and the free acids (non-salted form) are also within the scope of this invention.
Other amines that would make excellent starting materials in place of tromethamine are 2-amino-2-methyl-1-propanol, 2-amino-1-butanol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, and dihydroxymethylaminomethane.
Additionally, fatty amines, such as lauryl amine, coco amine, tallow amine, and oleoyl amine, and fatty ether amines, such as bis-(2-hydroxyethyl)isodecyloxypropylamine, when reacted with SVS produce mild surfactants that find utility where zwitterionic surfactants are desired, including personal care.
Other amines that are shown in FIG. 2 are produced via a similar series of reactions, except that FIG. 2 includes zwitterionic buffers from the amine 2-amino-2-methyl-1-propanol, as well as the polyamines derived from the reaction with acrylonitrile and the subsequent derivatives described above. Other amines can be utilized in addition to 2-amino-2-methyl-1-propanol to obtain excellent buffers are 2-amino-1-butanol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, and dihydroxymethylaminomethane. Reaction conditions could be created such that the alcohol groups on the amines listed above could be reacted with acrylonitrile as well, and then reduced to the amines and, if desired, reacted with SVS or MCA to impart zwitterionic character.
Polyamines with good properties for use in biological fermentations, purifications, storage and general handling can also be produced through the reaction of nitroalcohols and acrylonitrile, followed by reduction. Additional derivatization with SVS or MCA will result in zwitterionic buffers with a very large buffering range and capacity.
FIG. 3 shows the reaction of 2-methyl-2-nitro-1-propanol with acrylonitrile and its derivatives.
FIG. 4 shows the reaction of 2-nitro-2-ethyl-1,3-propanediol with acrylonitrile and its derivatives where x,y,and n are all integers where x and y are chosen independently, such that x+y=n and n is greater than zero.
FIG. 5 shows the reaction of 2-nitro-2-methyl-1,3-propanediol with acrylonitrile and its derivatives where x,y,and n are all integers where x and y are chosen independently, such that x+y=n and n is greater than zero.
FIG. 6 shows the reaction of tris(hydroxymethyl)nitromethane with acrylonitrile and its derivatives where x,y, z, and n are all integers where x, y and z are chosen independently, such that x+y+z=n and n is greater than zero.
FIG. 7 shows the reaction of 2-nitro-1,3-propanediol with acrylonitrile and its derivatives where x,y,and n are all integers where x and y are chosen independently, such that x+y=n and n is greater than zero.
FIG. 8 shows the reaction of 2-nitro-1-butanol with acrylonitrile and its derivatives.
FIGS. 2 through 8 are subject to the same clarifications as FIG. 1 with regard to the cyanoethylation and the formation of a more linear or branched structure as well as the addition of SVS or MCA in molar equivalents of primary amine groups or less than molar equivalents of primary amine groups present.
The buffers described thus far may also be ethoxylated, propoxylated, or butoxylated to modify their properties. Ethoxylation will tend to impart surfactancy to the resulting product. Propoxylation will add surfactancy, but also reduce the water solubility. This is useful in emulsion breaking and reverse emulsion breaking, this will also find utility in breaking up and dissolving biofilms. This is also desired in oil-field applications. Butoxylation will similarly shift the HLB to the hydrophobic. Combinations of ethoxylation, propoxylation, and butoxylation can be tailored to specific emulsion and reverse emulsion forming and breaking requirements. FIG. 9 shows alkoxylation of aminomethylpropanol. The direct 2 mole ethoxylation of 2-amino-2-methyl-1-propanol with 2 moles of ethylene oxide, as shown in FIG. 9 produces an excellent biological buffer with less chelation than 2-amino-2-methyl-1-propanol. The reaction of 2-amino-2-methyl-1-propanol with propylene oxide or butylene oxide yields a similarly less chelating product, as does the reaction with diethylene glycol. The reaction product of 2-amino-2-methyl-1-propanol with 1 mole of diethylene glycol as shown in FIG. 9 produces an ideal amine for gas scrubbing of H2S. This product is particularly useful because it does not bind to carbon dioxide and carbon monoxide in any appreciable amount. Thus making it ideal for tail gas scrubbing and maximizing the capacity of sulfur plants in refineries. Similar performance is seen with the reaction of the following amines 2-amino-1-butanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, tris(hydroxylmethyl)aminomethane, and 2-amino-1,3-propanediol.
The buffers described herein also make excellent starting materials for surfactants. FIG. 10 shows the synthesis of 2 very mild, high foaming, surfactants that are well suited for personal care applications were irritation is problematic, such as baby shampoo and face cleansers. Similar results are seen when 2-amino-1-butanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, tris(hydroxylmethyl)aminomethane, and 2-amino-1,3-propanediol are used as the starting material in place of 2-amino-2-methyl-1-propanol.
Polyamines with good properties for use in biological fermentations, purifications, storage and general handling can also be produced through the reaction of nitroalkanes and acrylonitrile, followed by reduction. Additional derivatization with SVS or MCA will result in zwitterionic buffers with a very large buffering range and capacity. FIG. 11 shows the synthesis of a series of buffers with 2-nitropropane as the starting material. FIG. 12 shows the synthesis of a series of buffers with 1-nitropropane as a starting material where n and m are integers where m+n is greater than zero and n is greater than or equal to m. Branching can be imparted on the buffers described in FIGS. 11 through 14 for the polyamines that have greater than 3 amine groups by reducing the resulting nitrile or polynitrile to the polyamine and then reacting with more acrylonitrile and then reducing the resulting nitrile groups to amine groups. This can be done repeatedly. As in FIG. 1, conditions can be chosen such that a more branched product results. A more linear product is produced by simply adding all the acrylonitrile in one step, and then reducing the resulting polynitrile to the polyamine. For FIGS. 12 through 14, the zwitterionic products can be made by adding MCA or SVS as shown in FIGS. 2 through 8.
FIG. 13 shows the synthesis of a series of buffers with nitroethane as a starting material where n and m are integers where m+n is greater than zero and n is greater than or equal to m. FIG. 14 shows the synthesis of a series of buffers with nitromethane as a starting material where x,y,z and n are integers and x+y+z=n and n is greater than zero.
Several descriptions and illustrations have been presented to enhance understanding of the present invention. One skilled in the art will know that numerous changes and variations are possible without departing from the spirit of the invention. Each of these changes and variations are within the scope of the present invention.
Another embodiment of the present invention is the synthesis of zwitterionic buffers with vinyl acids. FIG. 15 shows the synthesis of a family of zwitterionic buffers based on members of the acrylic acid family. However, other vinyl acids may be used. Vinyl acids such as acrylic, 3-butenoic acid, 4-pentenoic acid, and other carboxcylic acids with a double bond at the terminus. Carboxcylic acids with a triple bond at the terminus also can be utilized, similarly, an acid where the multiple bond is not at the terminus, such as hex-4-enoic acid, can also be utilized. However, due to the reduced commercial availability of such compounds, the preferred embodiment is the vinyl acid with a double bond at the terminus. One very large benefit of utilizing vinyl acids to make zwitterionic buffers is that the product does not need to be ion exchanged to produce a non-ionized form. In the market, both ionized, or sometimes called salted, and non-ionized forms sometimes called free acid or free base, are required. In situations where ionic strength must be very closely controlled, the non-ionized forms are more popular. For cases where increased water solubility and ease of solution are desired, the salted forms are preferred. It is understood to one skilled in the art, the present invention covers both the ionized and non-ionized forms of the buffers disclosed herein.
Another embodiment of the present invention is the sulfonate zwitterionic buffers derived from the reaction of an amine with an epichlorohydrin and sodium bisulfate condensate as described in FIG. 16. It is understood by one skilled in the art that other sulfate salts can be utilized to arrive at the desired molecular structure and is included in the present invention. FIGS. 17 through 25 teach the flexibility of the present invention to synthesize a series of a amine sulfonate or amino acid zwitterionic buffers from nitroalcohols or alkanolamines to produce zwitterionic buffers that have primary amino functionality or secondary amino functionality. In cases where there are more than one reactive group, amine, alcohol, or a combination, multiple sulfonate groups or acid groups can be reacted by adding more than one equivalent of the vinyl acid or the oxirane containing sulfonate.
Another embodiment of the current invention is to make zwitterionic buffers with cylcoamines as the starting material. The cycloamines result in a tertiary amino group that is less chelating and interferes less in biological functions. FIG. 26 shows the reaction of morpholine with a vinyl acid and morpholine with the oxirane sulfonate. FIG. 27 shows similar products, but utilizing hydroxyethyl piperazine. FIG. 28 shows the use of diamines as starting materials by using piperazine as the starting material. This is a good example of a synthesis of polyzwittterionic buffers as discussed earlier. FIG. 29 shows the use of ethylene amines to make zwitterionic buffers through reaction with vinyl acids or oxirane sulfonates. One skilled in the art will recognize that similar compounds can be made by using ethylene amines, such as monoethanolamine and the higher homologs, such as diethylenetriamine and is part of the invention disclosed herein.
Another embodiment of the current invention is the synthesis of zwitterionic amines that have primary, secondary, tertiary, and quaternary amine functionality. FIG. 30 shows this via oxirane sulfonate and amines. One skilled in the art will recognize that any primary, secondary, or tertiary amine can be used in place of the methyamines in FIG. 30. While not shown in the figure, one skilled in the art will recognize that the resulting amines can be reacted further with vinyl acids, monochloroacetic acid, sodium vinyl sulfonate, or an oxirane sulfonate to further add acidic character to the zwitterionic buffer.
Another embodiment of the current invention is the synthesis of mild surfactants from nitroalcohols. FIGS. 31 through 33 teach the synthesis of these mild surfactants. Lower molecular weight acids produce lower foaming mild surfactants, whereas higher molecular weight carboxcylic acids yield higher foam. Lauric acid is the preferred embodiment for a high foaming, mild surfact. Coconut fatty acid performs similarly, but at a lower cost. A good surfactant with low foam can be made using octanoic acid as the carboxcylic acid.
Another embodiment of the current invention is the synthesis of polyamines from nitroalcohols. FIGS. 34 and 35 teach the synthesis of diamines from nitroalcohols. FIG. 34 shows the synthesis with several hydroxyl groups present. It is understood by one skilled in the art that additional amino groups can be added by reacting more than one equivalent of epichlorohydrin to the nitroalcohol, up to the number of hydroxyl groups, and then reacting the same number of equivalents of amine to the oxirane containing amine. In the case where the nitroalcohol is reduced to the amino alcohol in the beginning, the addition of base, such as caustic, to the amino alcohol will assist in the reaction of the epichlorohydrin with the hydroxyl groups. Without the base, the epichlorohydrin will preferably react with the amine as outlined in the 1 equivelent addition depicted in FIG. 34 and FIG. 35. FIG. 36 demonstrates that tertiary amines can be used to make zwitterionic buffers with quaternary amine functionality from tertiary amines. While not explicitly shown, any other tertiary amine can be used as the starting material and is part of the invention described herein. FIG. 37 and FIG. 38 demonstrate that diamines can be made from nitroalcohols by reacting sequentially the nitroalcohol with epichlorohydrin and then the second equivalent of the nitroalcohol, followed by reduction. Also taught is that a reduction step can take place in the beginning to yield a diamine with two secondary amino groups. It is understood by one skilled in the art that the nitroalcohols or alkanolamines do not need to be symmetric, but others may be used in the synthesis of the diamine and is part of the invention disclosed herein.
FIG. 42 shows the synthesis of zwitterionic biological buffers from amino alcohols and itaconic acid. These buffers have two acid groups and increased buffering in the acidic range of pH 3-6. FIGS. 43 and 44 show the synthesis of zwitterionic buffers with primary amine groups. These buffers are preferred in applications such as personal care where secondary amines are seen as undesirable. The nitro diacids of FIG. 44 also have great utility as chemical intermediates when synthesizing bioactive molecules.
FIG. 45 shows the synthesis of a family of zwitterionic buffers from itaconic acid. The buffers in FIG. 45 are not limited to amino alcohols as starting materials and provide a wide range of molecular size and solubilities.
FIG. 46 shows the synthesis of a family of amphoteric surfactants. These surfactants are preferred for there mildness, ability to perform in hard water conditions and persistent lather when in the fatty tail is approximately 10-12 carbons in length. The R group in FIG. 46 is to encompass the fatty acid family of carbon chain lengths, generally from about 6 to about 22 carbons. In the specific cases illustrated of lauric amine and lauric dimethyl amine reacted with itaconic acid, it is understood by one in the art that any chain length amine can be used and is in within the scope of the invention herein. Particularly, but not limited to the fatty amines (carbon lengths of about 6 to about 22 carbons, branched and linear, saturated and unsaturated), isopropyl amine and butyl amine. The lower carbon chain lengths produce low foaming hard surface cleaners, while the carbon chains of about 8 to 10 tend to produce the most foam. Higher chain lengths find utility as mineral collectors in floatation processes such as those employed in iron and potash mining.
FIG. 47 shows the synthesis of nitro acids from nitroparaffins. As stated early, these are very flexible intermediates, particularly when synthesizing bioactive molecules. Reduction of the nitro acids, as shown in FIG. 48 produces zwitterionic buffers with primary amine character. In the case of nitroparaffins that have more than one hydrogen bound to the nitro bound carbon, more than one addition of the itaconic acid can occur. The substitution can occur up to the number of hydrogen atoms bound to the nitro bound carbon.
FIG. 49 shows the synthesis of zwitterionic buffers from 4-aminopyridine, FIG. 50 shows using the less stable ketimine conformation as the starting material. FIG. 51 shows the synthesis of sultaine type buffers from 4-aminopyridine. Additional buffers can be made by propoxylating and butoxylating 4-aminopyridine. The ethoxylating and propoxylating will reduce the water solubility and reduce the bioavailability. This is one method of extending the time a material is bioavailable by making it available slowly, particularly if the molecule is metabolized. Additionally, a triamine can be made by reacting 2-aminopyridine with arcrylonitrile and reducing it to the triamine, or reacting with allylamine to keep the aromatic nature of the six membered ring. The resulting buffers are excellent buffers in their own right, but also have great promise in treatment of multiple sclerosis, and other conditions that can benefit from calcium or other cation inhibition. The anionic components, in particular, are all groups that can chelate cations.
FIG. 52 outlines the synthesis of taurine derived zwitterionic buffers. These molecules, along with the products in FIG. 53, homotaurine derived zwitterionic buffers, are expected to find great utility in the purification of proteins and in cell culture media. FIG. 54 shows the synthesis of a series of zwitterionic buffers derived from aspartic acid. These compounds are expected to be very useful in electrophoresis gels as they have a unique charge density and size profile. The sultaine derivatives in FIG. 55 and FIG. 56 are expected to find great utility in cell culture media and in purification due to their zwitterionic nature and pKa range. The zwitterionic buffers of FIG. 57 are expected to be primarily useful in cell culture media. The buffers of FIG. 58 and FIG. 59 are ideally suited for use in electrophoresis gels and in isoelectric focusing. FIG. 60, FIG. 61 and FIG. 62 show the synthesis of zwitterionic amidoamine buffers for use cell culture media and purification.
FIG. 63 shows the synthesis of zwitterionic buffers that are expected to be useful in the treatment of multiple sclerosis (MS) and spinal cord injury by blocking potassium channels. The increased hydrogen bonding available through the sulfonate group is expected to enhance the efficacy over the traditional 4-aminopyridine therapy. While the figure shows only two compounds, one skilled in the art will recognize that any of the amino acid taurates, including, but not limted to those disclosed herein, particularly those of FIGS. 52, 53, 54, and 57. FIGS. 64 and 65 show the synthesis of a further class of amidoamine buffers that are expected to be effective therapies for MS and spinal cord injury due to the pKa and hydrogen bonding. FIGS. 66-68 shows the synthesis of a class of compounds that are excellent amidoamine buffers, particularly useful for electrophoresis and protein focusing. These are also expected to be excellent therapies for MS and spinal cord injury through potassium channel blocking. The more hydrogen bonding variants are expected to have greater efficacy. FIG. 69 shows the synthesis of a further class of amidomine buffers that are also expected to have utility as MS or spinal cord injury therapies. One skilled in the art will recognize that the amino acids used are not limited to those presented but any amino acid can be utilized and are within the scope of the present invention. In particular, the analogs based on methacrylic and other vinyl acids as the amino acid reacted with 4-aminopyridine are within the scope of the present invention, similar to the analogs presented in FIG. 15 where tromethamine is reacted with various acids to form a family of amino acids. FIGS. 70-72 teach a family of amidoamine buffers. FIG. 73 shows that any of the amidoamines presented herein, may be reduced to the aminoalcohol by reacting with hydrogen in the presence of a catalyst, such as raney nickel or raney cobalt, as well as reduced to the diamine by treatment with lithium aluminum hydride or similarly strong reducing agent.
As outlined earlier, one skilled in the art will recognize that the resulting amines can be reacted further with vinyl acids, monochloroacetic acid, sodium vinyl sulfonate, or an oxirane sulfonate to further add acidic character to the zwitterionic buffer. One skilled in the art will recognize that the salts and free acids and free bases of the compounds taught herein are within the scope of the invention. Additionally, to adjust the water solubility, it is useful to alkoxylate of the buffers taught herein, particularly with ethylene oxide, propylene oxide or butylenes oxide or a combination of alkoxylating agents in any amount or ratio to reach the desired result. The resulting alkoxylates will in some cases produce surfactants. Another way to make mild surfactants from the buffers taught is to esterify. FIGS. 74 and 75 show the esterification of the mono- and di- acid functional zwitterionics. It is understood by one skilled in the art that all the zwitterionics taught herein may undergo this reaction in a similar fashion to those explicitly shown. For example, the FIGS. 74 and 75 do not explicitly show the esterification of the products of FIG. 26, but it is understood that the esterification is similar enough to be recognized by one skilled in the art. The 4-aminopyridine derived zwitterionic buffers benefit from esterification in adjusting the bioavailability and water solubility, much as they do from alkoxylation, to improve their efficacy and reduce side effects when used as a therapy for MS, Alzheimer's disease, or other medical use.
The primary amines that are the basis for the zwitterionic buffers, may undergo disubstitution to form diacid functional buffers as shown in FIG. 76. These may be mono- or diesterified just as the itaconic acid based buffers in FIG. 75. FIG. 77 expands on the amidoamines that can be synthesized from the zwitterionic buffers. The amidoamine formation may also be carried out by diamines to create dimmers, or with the secondary diamines, such as coco diamine or tallow diamine to produce surfactants that act as corrosion and scale inhibitors.
FIG. 78 shows the synthesis of a variety of 4-aminopyridine derivatives that are useful buffers. The varying amine strength and water solubility give them unique properties.
FIG. 79 shows the condensation polymerization of the hydroxyl functional zwitterionic buffers. As shown, linear polyesters or polyester prepolymers are produced. By using the buffers with varying hydroxyl numbers, a hydroxyl functional polymer results. When used as a prepolymer, greater cross-linking can be introduced when incorporated into a polyurea, polyurethane, or polyether. If condensed with the itaconic based buffers, such as those in FIG. 42, or other polyacid functional monomers or prepolymers, a 3 dimensional polyester polymer matrix can be achieved. FIG. 80 further clarifies the ability to make diamines from the amides taught herein. In FIG. 80, where G is —OH, it can either remain intact when done under milder reduction conditions, or be converted to —H when harsher conditions, such as when LAH is used. The most useful of these amidoamines and diamines is expected to be those where A=D=E=M=J=L=-CH2OH.
FIGS. 81, 82, 83 and 84 demonstrate how the sulfonate buffers can be converted to sulfonamides. Sulfonamides have a wide range of known biological activity and these sulfonamides are expected to have increased antimicrobial properties versus their related sulfonates or carboxcylic acid functional zwitterionics. It is well known in the art that sulfonamides can be reduced under mild conditions to the suflonimides, which are within the scope of the invention disclosed herein.
FIG. 85 shows the synthesis of quaternary amine salts. These products are particularly useful in diagnostic kits for condution, as well as there antimicrobial properties. The case where A=-CH2OH and D=E=R=R′=—CH3 is the most useful of this class, but the other permutations are useful when the water solubility needs to be increased or decreased.
FIGS. 86 and 87 teach the synthesis of sulfonate esters from the zwitterionic buffers. These esters allow for changing the water solubility, while maintaining buffering capacity. FIGS. 88 and 89 teach the synthesis of zwitterionic buffers with primary amino functionality. Again, the 4-aminopyridine moiety containing buffers are promising targets for therapies to treat MS and potentially Alzheimer's disease or other diseases that involve demyelination or other myelin anomalies.
FIG. 90 expands on the quaternary amine salts shown in FIG. 85.
An additional use for the molecules taught herein is the use in print media to reduce bronzing, similar to that taught in U.S. patent application Ser. No. 12/248,323, which is incorporated by reference.
Several descriptions and illustrations have been presented to enhance understanding of the present invention. One skilled in the art will know that numerous changes and variations are possible without departing from the spirit of the invention. Each of these changes and variations are within the scope of the present invention.

## Claims

1. A biological buffer of the following structure:



where A, D, and E are independently chosen from —H, —CH3, —CH2CH3, and —CH2OH, and G is chosen from —H, —CH3, —OH, where A, E and D may not all equal —H.

2. The biological buffer of claim 1 where A═D═E═—CH2OH, and G═—CH3.

3. The biological buffer of claim 1 where A═D═E═—CH2OH, and G═—H.

4. The biological buffer of claim 1 where A═D═—CH3 and E═—CH2OH and G═—CH3.

5. The biological buffer of claim 1 where A═D═—CH3 and E═—CH2OH and G═—H.

6. A Biological Buffer of the following structure:



where A and D are independently chosen from —H, —CH3, —CH2CH3, and —CH2OH, E is chosen from —CH2CH3 and —CH2OH.

7. The biological buffer of claim 6 where A═D═E═—CH2OH.

8. The biological buffer of claim 6 where A═D═—CH3 and E═—CH2OH.