dorzolamide and sulfamic-acid

Carbonic anhydrase inhibitors (CAIs) of the sulfonamide and sulfamate type are clinically used drugs as diuretics, antiglaucoma, antiepileptic, antiobesity and anti-high altitude disease agents. Anticancer agents based on CAIs are also in clinical development for the management of hypoxic, metastatic tumors. Acetazolamide, methazolamide, dichlorophenamide, dorzolamide and brinzolamide are mainly used as antiglaucoma drugs, sulthiame, topiramate and zonisamide as antiepileptic/antiobesity agents, celecoxib and polmacoxib are dual carbonic anhydrase/cycloxygenase inhibitors. Girentuximab, a monoclonal antibody and SLC-0111, a sulfonamide inhibitor, are in clinical trials as anticancer agents.. The drug interactions with many classes of pharmacological agents are reviewed. Some of these drugs, such as acetazolamide, topiramate and celecoxib show a large number of interactions with non-steroidal anti-inflammatory drugs (NSAIDs), diuretics, antiepileptics, immunosupressants, anticholinesterase drugs, β-blockers, anesthetics, oral contraceptives, anticancer agents, antifungals, anti-mycobacterials, lithium, metformin and clopidogrel.. The multiple drug interactions in which CAIs are involved should be carefully considered when such drugs are used in combination with the drug classes mentioned above, as the risks of developing toxicity and serious side effects if the dosages are not adjusted are high. There are also synergistic effects between CAIs and some NSAIDs, anticancer agents and benzodiazepines for the management of cystoid macular edema, some tumor types and neuropathic pain, respectively.

Topics: Acetazolamide; Anti-Inflammatory Agents, Non-Steroidal; Anti-Obesity Agents; Antibodies, Monoclonal; Anticonvulsants; Antineoplastic Agents; Benzodiazepines; Carbonic Anhydrase Inhibitors; Celecoxib; Clinical Trials as Topic; Contraindications; Drug Interactions; Drug-Related Side Effects and Adverse Reactions; Fructose; Humans; Isoxazoles; Methazolamide; Phenobarbital; Sulfanilamide; Sulfanilamides; Sulfonamides; Sulfonic Acids; Thiazines; Thiophenes; Topiramate; Zonisamide

The fungal pathogen Candida glabrata encodes for a β-carbonic anhydrase (CA, EC 4.2.1.1), CgNce103, recently discovered. Only anions have been investigated as CgNce103 inhibitors up until now. Here we report the first sulfonamides inhibition study of this enzyme. Simple sulfonamides showed weak or moderate CgNce103 inhibitory properties, whereas acetazolamide, and a series of 4-substituted ureido-benzene-sulfonamides, sulfamates and sulfamides showed effective CgNce103 inhibitory properties, with KIs in the range of 4.1-115 nM, being also ineffective as human CA II inhibitors. As there is significant resistance of C. glabrata clinical isolates to many classical antifungal agents, inhibition of the β-CA from this organism may allow an interesting means of controlling the pathogen growth, eventually leading to antifungals with a novel mechanism of action.

Topics: Acetazolamide; Amino Acid Sequence; Antifungal Agents; Candida glabrata; Carbonic Anhydrase Inhibitors; Carbonic Anhydrases; Humans; Kinetics; Molecular Sequence Data; Phylogeny; Protein Binding; Sequence Alignment; Structure-Activity Relationship; Sulfonamides; Sulfonic Acids

The α-carbonic anhydrase (CA, EC 4.2.1.1) Astrosclerin-3 previously isolated from the living fossil sponge Astrosclera willeyana (Jackson et al., Science 2007, 316, 1893), was cloned, kinetically characterized and investigated for its inhibition properties with sulfonamides and sulfamates. Astrosclerin-3 has a high catalytic activity for the CO(2) hydration reaction to bicarbonate and protons (k(cat) of 9.0×10(5) s(-1) and k(cat)/K(m) of 1.1×10(8) M(-1) × s(-1)), and is inhibited by various aromatic/heterocyclic sulfonamides and sulfamates with inhibition constants in the range of 2.9 nM-8.85 μM. Astrosclerin, and the human isoform CA II, display similar kinetic properties and affinities for sulfonamide inhibitors, despite more than 550 million years of independent evolution. Because Astrosclerin-3 is involved in biocalcification, the inhibitors characterized here may be used to gain insights into such processes in other metazoans.

Topics: Amino Acid Sequence; Animals; Carbonic Anhydrases; Cloning, Molecular; Fossils; Humans; Molecular Sequence Data; Porifera; Protein Binding; Sequence Alignment; Sulfonamides; Sulfonic Acids

A β-carbonic anhydrase (CA, EC 4.2.1.1) from the bacterial pathogen Brucella suis, bsCA II, has been cloned, purified, and characterized kinetically. bsCA II showed high catalytic activity for the hydration of CO(2) to bicarbonate, with a k(cat) of 1.1×10(6), and k(cat)/K(m) of 8.9×10(7)M(-1)s(-1). A panel of sulfonamides and sulfamates have been investigated for inhibition of this enzyme. All types of activities, from the low nanomolar to the micromolar, have been detected for these derivatives, which showed inhibition constants in the range of 7.3nM-8.56μM. The best bsCA II inhibitors were some glycosylated sulfanilamides, aliphatic sulfamates, and halogenated sulfanilamides, with inhibition constants of 7.3-87nM. Some of these dual inhibitors of bsCA I and II, also inhibited bacterial growth in vitro, in liquid cultures. These promising data on live bacteria allow us to propose bacterial β-CA inhibition as an approach for obtaining anti-infective agents with a new mechanism of action compared to classical antibiotics.

Topics: Anti-Bacterial Agents; Brucella suis; Carbonic Anhydrase Inhibitors; Carbonic Anhydrases; Cloning, Molecular; Drug Design; Drug Discovery; Inhibitory Concentration 50; Kinetics; Sulfonamides; Sulfonic Acids

The two β-carbonic anhydrases (CAs, EC 4.2.1.1) from the bacterial pathogen Salmonella enterica serovar Typhimurium, stCA 1 and stCA 2, were investigated for their inhibition with a large panel of sulfonamides and sulfamates. Unlike inorganic anions, which are weak, millimolar inhibitors of the two enzymes [Vullo et al., Bioorg. Med. Chem. Lett.2011, 21, 3591], sulfonamides and sulfamates are effective micro-to nanomolar inhibitors of the two enzymes. Various types of inhibitors have been detected among the 38 investigated sulfonamides/sulfamates, with K(I)s in the range of 31 nM-5.87 μM. The best stCA 1 inhibitors were acetazolamide and benzolamide-based compounds, whereas the best stCA 2 inhibitors were sulfonylated benzenesulfonamides and amino-benzolamide derivatives (K(I)s in the range of 31-90 nM). 3-Fluoro-5-chloro-4-aminobenzolamide showed an inhibition constant of 51 nM against stCA 1 and of 38 nM against stCA 2, being the best inhibitor detected so far for these enzymes. As many strains of S. enterica show extensive resistance to classical antibiotics, inhibition of the β-CAs investigated here may be useful for developing novel antibacterials, targeting β-CAs which may be involved in pathogenicity and invasion of some bacteria.

Topics: Anti-Bacterial Agents; Carbonic Anhydrase Inhibitors; Carbonic Anhydrases; Salmonella Infections; Salmonella typhimurium; Structure-Activity Relationship; Sulfonamides; Sulfonic Acids

The protein encoded by the Nce103 gene of Saccharomyces cerevisiae, a beta-carbonic anhydrase (CA, EC 4.2.1.1) designated as scCA, has been cloned, purified, characterized kinetically and investigated for its inhibition with a series of sulfonamides and one sulfamate. The enzyme showed high CO(2) hydrase activity, with a k(cat) of 9.4x10(5)s(-1), and k(cat)/K(M) of 9.8x10(7)M(-1)s(-1). Simple benzenesulfonamides substituted in 2-, 4- and 3,4-positions of the benzene ring with amino, alkyl, halogeno and hydroxyalkyl moieties were weak scCA inhibitors with K(I)s in the range of 0.976-18.45 microM. Better inhibition (K(I)s in the range of 154-654 nM) was observed for benzenesulfonamides incorporating aminoalkyl/carboxyalkyl moieties or halogenosulfanilamides; benzene-1,3-disulfonamides; simple heterocyclic sulfonamides and sulfanilyl-sulfonamides. The clinically used sulfonamides/sulfamate (acetazolamide, ethoxzolamide, methazolamide, dorzolamide, topiramate, celecoxib, etc.) generally showed effective scCA inhibitory activity, with K(I)s in the range of 82.6-133 nM. The best inhibitor (K(I) of 15.1 nM) was 4-(2-amino-pyrimidin-4-yl)-benzenesulfonamide. These inhibitors may be useful to better understand the physiological role of beta-CAs in yeast and some pathogenic fungi which encode orthologues of the yeast enzyme and eventually for designing novel antifungal therapies.

Topics: Amino Acid Sequence; Antifungal Agents; Carbonic Anhydrase Inhibitors; Carbonic Anhydrases; Kinetics; Molecular Sequence Data; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Sequence Alignment; Sequence Homology, Amino Acid; Sulfonamides; Sulfonic Acids

The beta-carbonic anhydrase (CA, EC 4.2.1.1) encoded by the gene Rv1284 (mtCA 1) of Mycobacterium tuberculosis shows appreciable catalytic activity for CO(2) hydration, with a k(cat) of 3.9 x 10(5) s(-1) and a k(cat)/K(m) of 3.7 x 10(7) M(-1) s(-1). A panel of 36 sulfonamides and one sulfamate, some of which are used clinically, were assayed for their effect on mtCA 1 catalytic activity. Most sulfonamides exhibited K(I) values in the range of 1-10 microM, but several derivatives, including sulfanilyl-sulfonamides acetazolamide, methazolamide, dichlorophenamide, dorzolamide, brinzolamide, benzolamide, and the sulfamate topiramate, exhibited submicromolar inhibition (K(I) values of 0.481-0.905 microM). The best inhibitors were 3-bromosulfanilamide and indisulam (K(I) values of 97-186 nM). This study demonstrates that mtCA 1 can be inhibited by sulfonamides and sulfamates and thus has potential for developing antimycobacterial agents with an alternate mechanism of action. This is an important finding to explore further, as many strains exhibit multidrug resistance and extensive multidrug resistance to existing therapeutics.

Topics: Amino Acid Sequence; Anti-Bacterial Agents; Base Sequence; Carbonic Anhydrase Inhibitors; Carbonic Anhydrases; Catalysis; Cloning, Molecular; Drug Resistance, Multiple, Bacterial; Humans; Molecular Sequence Data; Mycobacterium tuberculosis; Recombinant Proteins; Structure-Activity Relationship; Sulfonamides; Sulfonic Acids

The Rv3273 gene product of Mycobacterium tuberculosis, a beta-carbonic anhydrase (CA, EC 4.2.1.1), mtCA 3, shows appreciable catalytic activity for CO(2) hydration (k(cat) of 4.3 x 10(5) s(-1), and k(cat)/K(m) of 4.0 x 10(7) M(-1) x s(-1)). A series of sulfonamides/sulfamates was assayed for their interaction with mtCA 3. Sulfanilyl-sulfonamides, acetazolamide, methazolamide, ethoxzolamide, dichlorophenamide, dorzolamide, brinzolamide, benzolamide, and zonisamide, showed effective, submicromolar inhibition (K(I)s of 104-611 nM), the best inhibitor being 2-amino-pyrimidin-4-yl-sulfanilamide (K(I) of 91 nM).

Topics: Amino Acid Sequence; Biocatalysis; Carbonic Anhydrase Inhibitors; Carbonic Anhydrases; Cloning, Molecular; Molecular Sequence Data; Mycobacterium tuberculosis; Sulfonamides; Sulfonic Acids

A series of fluorinated-phenylsulfamates have been prepared by sulfamoylation of the corresponding phenols and the inhibition of four physiologically relevant carbonic anhydrase (CA, EC 4.2.1.1) isozymes, the cytosolic CA I and II (off-targets), and the transmembrane, tumor-associated CA IX and XII is investigated. Unlike the lead molecule (phenylsulfamate), a very potent CA I and II inhibitor and a modest CA IX/XII inhibitor, the fluorinated sulfamates were stronger inhibitors of CA IX (K(I)s of 2.8-47 nM) and CA XII (K(I)s of 1.9-35 nM) than of CA I (K(I)s of 53-415 nM) and CA II (K(I)s of 20-113 nM). Some of these compounds were selective CA IX over CA II inhibitors, with selectivity ratios in the range of 11.4-12.1, making them interesting candidates for targeting hypoxic tumors overexpressing CA IX and/or XII.

Topics: Antigens, Neoplasm; Carbonic Anhydrase I; Carbonic Anhydrase II; Carbonic Anhydrase Inhibitors; Carbonic Anhydrase IX; Carbonic Anhydrases; Catalytic Domain; Humans; Protein Isoforms; Structure-Activity Relationship; Sulfonic Acids

Two approaches were used to design inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1): the tail and the ring approaches. Aliphatic sulfamates constitute a class of CA inhibitors (CAIs) that cannot be classified in either one of these categories. We report here the detailed inhibition profile of four such compounds against isoforms CAs I-XIV, the first crystallographic structures of these compounds in adduct with isoform II, and molecular modeling studies for their interaction with hCA IX. Aliphatic monosulfamates/bis-sulfamates were nanomolar inhibitors of hCAs II, IX, and XII, unlike aromatic/heterocyclic sulfonamides that promiscuously inhibit most CA isozymes with low nanomolar affinity. The bis-sulfamates incorporating 8 or 10 carbon atoms showed higher affinity for the tumor-associated hCA IX compared to hCA II, whereas the opposite was true for the monosulfamates. The explanation for their interaction with CA active site furnishes insights for obtaining compounds with increased affinity/selectivity for various isozymes.

Topics: Antigens, Neoplasm; Carbonic Anhydrase II; Carbonic Anhydrase Inhibitors; Carbonic Anhydrase IX; Carbonic Anhydrases; Catalytic Domain; Drug Design; Humans; Models, Molecular; Protein Binding; Structure-Activity Relationship; Sulfonic Acids

The secretory isozyme of human carbonic anhydrase (hCA, EC 4.2.1.1), hCA VI, has been cloned, expressed, and purified in a bacterial expression system. The kinetic parameters for the CO2 hydration reaction proved hCA VI to possess a kcat of 3.4 x 10(5) s-1 and kcat/KM of 4.9 x 10(7) M-1 s-1 (at pH 7.5 and 20 degrees C). hCA VI has a significant catalytic activity for the physiological reaction on the same order of magnitude as the ubiquitous isoform CA I or the transmembrane, tumor-associated isozyme CA IX. A series of sulfonamides and one sulfamate have been tested for their interaction with this isozyme. Simple benzenesulfonamides were rather ineffective hCA VI inhibitors, with inhibition constants in the range of 1090-6680 nM. Better inhibitors were detected among such derivatives bearing 2- or 4-amino-, 4-aminomethyl-, or 4-hydroxymethyl moieties or among halogenated sulfanilamides (KI values of 608-955 nM). Some clinically used compounds, such as acetazolamide, methazolamide, ethoxzolamide, dichlorophenamide, dorzolamide, brinzolamide, topiramate, sulpiride, and indisulam, or the orphan drug benzolamide, showed effective hCA VI inhibitory activity, with inhibition constants of 0.8-79 nM. The best inhibitors were brinzolamide and sulpiride (KI values of 0.8-0.9 nM), the latter compound being also a CA VI-selective inhibitor. The metallic taste reported as a side effect after the treatment with systemic sulfonamides may be due to the inhibition of the salivary CA VI. Some of the compounds investigated in this study might be used as additives in toothpastes for reducing the acidification produced by the relevant CO2 hydrase activity of enamel CA VI, which leads to the formation of protons and bicarbonate and may have a role in cariogenesis.

Topics: Amino Acid Sequence; Carbonic Anhydrase Inhibitors; Carbonic Anhydrases; Catalysis; Cloning, Molecular; DNA; Humans; Isoenzymes; Molecular Sequence Data; Protein Subunits; Sequence Homology, Amino Acid; Structure-Activity Relationship; Sulfonamides; Sulfonic Acids

The cytosolic human carbonic anhydrase (hCA, EC 4.2.1.1) isozyme III (hCA III) has been cloned and purified by the GST-fusion protein method. Recombinant pure hCA III had the following kinetic parameters for the CO(2) hydration reaction at 20 degrees C and pH 7.5: k(cat) of 1.3 x 10(4) s(-1) and k(cat)/K(M) of 2.5 x 10(5) M(-1) s(-1), being a slower catalyst for the physiological reaction as compared to the genetically related cytosolic isoforms hCA I and II. An inhibition study with a library of sulfonamides and one sulfamate, some which are clinically used compounds, is reported. hCA III is less prone to be inhibited by these compounds as compared to hCA I and II for which many low nanomolar inhibitors were detected earlier. The best hCA III inhibitors were prontosil, sulpiride, indisulam, benzolamide, aminobenzolamide, and 4-amino-6-chloro-benzene-1,3-disulfonamide which showed K(I)s in the range of 2.3-18.1 microM. Clinically used compounds such as acetazolamide, methazolamide, ethoxzolamide, dorzolamide, brinzolamide, topiramate, zonisamide, celecoxib, and valdecoxib were less effective hCA III inhibitors, with affinities in the range of 154-2200 microM. This is the first study in which low micromolar hCA III inhibitors are reported.

Topics: Amino Acid Sequence; Carbonic Anhydrase III; Carbonic Anhydrase Inhibitors; Cloning, Molecular; Cytosol; Enzyme Activation; Humans; Isoenzymes; Kinetics; Molecular Sequence Data; Recombinant Proteins; Structure-Activity Relationship; Sulfonamides; Sulfonic Acids

We have cloned and sequenced Helicobacter pylori alpha-class carbonic anhydrase (hpCA) from patients with different gastric mucosal lesions, including gastritis (n=15), ulcer (n=6), and cancer (n=16). Although several polymorphisms were newly identified such as 12Ala, 13Thr, 16Ile, and 168Phe, there was no significant relevance of any polymorphism with gastric mucosal lesion types. A library of sulfonamides/sulfamates has been investigated for the inhibition of hpCA, whereas new derivatives have been obtained by attaching 4-tert-butyl-phenylcarboxamido/sulfonamido tails to benzenesulfonamide/1,3,4-thiadiazole-2-sulfonamide scaffolds. All types of activity for inhibition of hpCA have been detected. Dorzolamide and simple 4-substituted benzenesulfonamides were weak inhibitors (KI 873-4360 nM). Sulfanilamide, orthanilamide, some of their derivatives, and indisulam showed better activity (KI 413-640 nM), whereas most of the clinically used inhibitors, such as methazolamide, ethoxzolamide, dichlorophenamide, brinzolamide, topiramate, zonisamide, etc., acted as medium-potency inhibitors (KI 105-378 nM). Some potent hpCA inhibitors were detected too (KI 12-84 nM) among acetazolamide, 4-amino-6-chloro-1,3-benzenedisulfonamide and some newly designed compounds incorporating lipophilic tails. Some of the newly prepared derivatives had selectivity ratios for inhibiting hpCA over hCA II in the range of 1.25-3.48, showing thus some selectivity for inhibiting the bacterial enzyme. Since hpCA is essential for the survival of the pathogen in acid, it might be used as a new pharmacologic tool in the management of drug-resistant H. pylori.

Topics: Amino Acid Sequence; Carbonic Anhydrase Inhibitors; Carbonic Anhydrases; Cloning, Molecular; DNA, Bacterial; Gastric Mucosa; Gastritis; Helicobacter pylori; Humans; Molecular Sequence Data; Polymorphism, Genetic; Stomach Neoplasms; Stomach Ulcer; Sulfonamides; Sulfonic Acids

A series of bis-sulfamates incorporating aliphatic, aromatic, or betulinyl moieties in their molecules was obtained by reaction of the corresponding diols/diphenols with sulfamoyl chloride. The library of bis-sulfamates thus obtained was tested for the inhibition of three physiologically relevant human carbonic anhydrase (hCA, EC 4.2.1.1) isozymes, the cytosolic hCA I and II, and the transmembrane, tumor-associated hCA IX. The new compounds reported here inhibited hCA I with K(I) s in the range of 79 nM-16.45 microM, hCA II with K(I) s in the range of 6-643 nM, and hCA IX with K(I) s in the range of 4-5400 nM. Several low nanomolar hCA IX inhibitors were detected, such as 1,8-octylene-bis-sulfamate or 1,10-decylene-bis-sulfamate (K(I) s in the range of 4-7 nM), which showed good selectivity ratios (in the range of 3.50-3.85) for hCA IX over hCA II inhibition. The most selective hCA IX inhibitor was phenyl-1,4-dimethylene-bis-sulfamate (K(I) of 61.6 nM), which was a 10.43 times better hCA IX than hCA II inhibitor. These derivatives are interesting candidates for the development of novel antitumor therapies targeting hypoxic tumors, since hCA IX is highly overexpressed in such tissues, and its presence is correlated with bad prognosis and unfavorable clinical outcome.

Topics: Antigens, Neoplasm; Carbonic Anhydrase I; Carbonic Anhydrase II; Carbonic Anhydrase Inhibitors; Carbonic Anhydrase IX; Carbonic Anhydrases; Cytosol; Humans; Isoenzymes; Neoplasm Proteins; Structure-Activity Relationship; Sulfonic Acids

An inhibition study of the human and bovine membrane-associated isozymes of carbonic anhydrase (CA, EC 4.2.1.1), hCA IV and bCA IV, with a series of sulfonamides and sulfamates, some of which are widely clinically used, such as acetazolamide, methazolamide, ethoxzolamide, topiramate, dorzolamide, dichlorophenamide, celecoxib, and valdecoxib among others, is reported. In contrast to bCA IV, which is generally strongly inhibited by most of these derivatives, hCA IV has a rather different inhibition profile. Several of these compounds such as acetazolamide, ethoxzolamide, and bromosulfanilamide are potent hCA IV inhibitors (K(i)'s of 74-93 nM), others, such as celecoxib and some halogenated sulfanilamides are medium potency inhibitors (K(i)'s of 450-880 nM) whereas most of them are weak hCA IV inhibitors (methazolamide: 6.2 microM; dorzolamide 8.5 microM; topiramate 4.9 microM; dichlorophenamide: 15.3 microM). The hCA IV/bCA IV inhibition ratios for all the investigated compounds ranged between 1.05 (for acetazolamide) and 198.37 (for dorzolamide). Based on these results, we doubt that hCA IV is indeed one of the main contributors to the intraocular pressure (IOP) lowering effects of sulfonamide CA inhibitors, in addition to hCA II, as hypothesized earlier by Maren et al. (Mol. Pharmacol.1993, 44, 901-906). Indeed, both the very good hCA IV inhibitors (acetazolamide and ethoxzolamide) as well as the quite weak hCA IV inhibitors (methazolamide, dorzolamide, or dichlorophanamide) are effective in lowering IOP when administered either systemically or topically. The membrane-associated isozyme which probably is critical for aqueous humor secretion is hCA XII and not hCA IV.

Topics: Animals; Carbonic Anhydrase Inhibitors; Carbonic Anhydrase IV; Cattle; Dose-Response Relationship, Drug; Humans; Isoenzymes; Kinetics; Membrane Proteins; Structure-Activity Relationship; Sulfonamides; Sulfonic Acids

A lately discovered carbonic anhydrase (hCA, EC 4.2.1.1), the mitochondrial hCA VB, was cloned, expressed, and purified. Kinetic parameters proved it to be 3.37 times more effective than hCA VA as a catalyst for the physiological reaction, with kcat = 9.5 x 10(5) s(-1) and kcat/K(M) = 9.8 x 10(7) M(-1) s(-1), being second only to hCA II among the 16 isoforms presently known in humans. We investigated the inhibition of hCA VB with a library of sulfonamides/sulfamates, some of which are clinically used compounds. Benzenesulfonamides were ineffective inhibitors, whereas derivatives bearing 4-amino, 4-hydrazino, 4-methyl, 4-carboxy moieties or halogenated sulfanilamides were more effective (Ki's of 1.56-4.3 microM). Among the 10 clinically used compounds, acetazolamide, benzolamide, topiramate, and indisulam showed effective inhibitory activity (Ki's of 18-62 nM). Three compounds showed better activity against hCA VB over hCA II, among which were sulpiride and ethoxzolamide, which were 2 times more effective inhibitors of the mitochondrial over the cytosolic isozyme. hCA VB is a druggable target and some of its inhibitors may lead to the development of novel antiobesity therapies.

Topics: Amino Acid Sequence; Carbonic Anhydrase Inhibitors; Carbonic Anhydrase V; Catalysis; Cloning, Molecular; Humans; Isoenzymes; Kinetics; Mitochondria; Molecular Sequence Data; Structure-Activity Relationship; Sulfonamides; Sulfonic Acids