Aydın Salman

Discovery of Low Nanomolar and Subnanomolar Inhibitors of the Mycobacterial β-Carbonic Anhydrases Rv1284 and Rv3273

A series of 2-(hydrazinocarbonyl)-3-aryl-1H-indole-5-sulfonamides has been derivatized by reaction with 2,4,6-trimethylpyrylium perchlorate, leading to pyridinium derivatives. The new sulfonamides were evaluated as inhibitors of two beta-carbonic anhydrases (CAs, EC 4.2.1.1) from Mycobacterium tuberculosis, Rv1284 and Rv3273. The whole series showed excellent nanomolar inhibitory activity, with several subnanomolar inhibitors being detected. Rv1284 and Rv3273 have potential for developing antimycobacterial agents with an alternate mechanism of action.

Synthesis and antituberculosis activity of 5-methyl/trifluoromethoxy-1H-indole-2,3-dione 3-thiosemicarbazone derivatives

New series of 5-methyl/trifluoromethoxy-1H-indole-2,3-dione 3-thiosemicarbazones 3a-t, 1-methyl-5-methyl/trifluoromethoxy-1H-indole-2,3-dione 3-thiosemicarbazones 4a-y and 5-trifluoromethoxy-1-morpholinomethyl-1H-indole-2,3-dione 3-thiosemicarbazones 5a-m were synthesized. The structures of the synthesized compounds were confirmed by spectral data and elemental analysis. The new 5-methyl/trifluoromethoxy-1H-indole-2,3-dione derivatives, along with previously synthesized 5-methyl-1H-indole-2,3-dione 3-thiosemicarbazones 6a-l, were evaluated for in vitro antituberculosis activity against Mycobacterium tuberculosis H37Rv. 5-Methyl-1H-indole-2,3-dione 3-thiosemicarbazones (3b, 3d, 3f, 6c, 6d, and 6f), 5-trifluoromethoxy-1H-indole-2,3-dione 3-thiosemicarbazones (3q-s) and 5-trifluoromethoxy-1-morpholinomethyl-1H-indole-2,3-dione 3-thiosemicarbazones (5e and 5j-l) were found to be the most potent inhibitors of M. tuberculosis growth described in this study.

Carbonic anhydrase inhibitors. Aromatic/heterocyclic sulfonamides incorporating phenacetyl, pyridylacetyl and thienylacetyl tails act as potent inhibitors of human mitochondrial isoforms VA and VB.

A series of aromatic/heterocyclic sulfonamides incorporating phenyl(alkyl), halogenosubstituted-phenyl- or 1,3,4-thiadiazole-sulfonamide moieties and thienylacetamido; phenacetamido and pyridinylacetamido tails were prepared and assayed as inhibitors of four physiologically relevant carbonic anhydrase (CA, EC 4.2.1.1) isoforms, the cytosolic human (h) hCA I and hCA II, and the mitochondrial hCA VA and hCA VB. The new compounds showed moderate inhibition of the two cytosolic isoforms (K(I)s of 50-390nM) and excellent inhibitory activity against the two mitochondrial enzymes, with many low nanomolar inhibitors detected (K(I)s in the range of 5.9-10.2nM). All substitution patterns explored here lead to effective hCA VA/VB inhibitors. Some hCA VA/VB selective inhibitors were also detected, with selectivity ratios for inhibiting the mitochondrial over the cytosolic isozymes of around 55.5-56.9. As hCA VA/VB are involved in several biosynthetic processes catalyzed by pyruvate carboxylase, acetyl CoA carboxylase, and carbamoyl phosphate synthetases I and II, providing the bicarbonate substrate to these carboxylating enzymes involved in fatty acid biosynthesis, their selective inhibition may lead to the development of antiobesity agents possessing a new mechanism of action.

Carbonic anhydrase inhibitors. Phenacetyl-, pyridylacetyl- and thienylacetyl-substituted aromatic sulfonamides act as potent and selective isoform VII inhibitors

A series of aromatic/heterocyclic sulfonamides incorporating phenyl(alkyl), halogenosubstituted-phenyl- or 1,3,4-thiadiazole-sulfonamide moieties and thienylacetamido; phenacetamido- and pyridinylacetamido tails were prepared and assayed as inhibitors of cytosolic human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms hCA I, II and VII. The new compounds showed moderate inhibition of the two ubiquitous isoforms I and II (K(I)s of 50-390 nM) and excellent inhibitory activity against the brain associated hCA VII (K(I)s in the range of 4.7-8.5 nM). Isoform VII highly selective inhibitors are being detected for the first time, with selectivity ratios for inhibiting CA VII over CA II of 11-75, and for inhibiting CA VII over CA I of 10-49, which may be useful for understanding the role of CA VII in epileptogenesis and other physiologic processes.

Carbonic anhydrase inhibitors : Synthesis and inhibition studies against mammalian isoforms I-XV with a series of 2-(hydrazinocarbonyl)-3-substituted-phenyl-1H-indole-5-sulfonamides

A series of 2-(hydrazinocarbonyl)-3-substitutedphenyl-1H-indole-5-sulfonamides possessing various 2-, 3- or 4- substituted phenyl groups with methyl-, halogeno- and methoxy- functionalities, as well as the perfluorophenyl moiety have been synthesized and evaluated as inhibitors of 13 catalytically active, mammalian carbonic anhydrase (CA, EC 4.2.1.1) isoforms, that is, CA I-CA XV (of human (h) or murine (m) origin). The new compounds were ineffective inhibitors of isozymes hCA III, hCA IV, hCA VA, hCA VB, hCA VI and mCA XIII, moderate inhibitors of hCA I, hCA VII, hCA IX and mCA XV, and excellent, low-nanomolar inhibitors of hCA II and hCA XIV. The substitution pattern of the aromatic group in the 3-position of the indole ring influenced biological activity and isozyme inhibition profiles in this series of sulfonamides. Some of the best and most selective hCA XIV and mCA XV inhibitors ever reported have been identified in this study.

Carbonic anhydrase inhibitors. Synthesis of 2,4,6-trimethylpyridinium derivatives of 2-(hydrazinocarbonyl)-3-aryl-1H-indole-5-sulfonamides acting as potent inhibitors of the tumor-associated isoform IX and XII

A series of 2-(hydrazinocarbonyl)-3-aryl-1H-indole-5-sulfonamides possessing various 2-, 3- or 4- substituted phenyl groups with methyl-, halogeno- and methoxy-functionalities, or a perfluorophenyl moiety, has been derivatized by reaction with 2,4,6-trimethylpyrylium perchlorate. The new sulfonamides were evaluated as inhibitors of four mammalian carbonic anhydrase (CA, EC 4.2.1.1) isoforms, that is, CA I, II (cytosolic), CA IX and XII (transmembrane, tumor-associated forms). Excellent inhibitory activity was observed against hCA IX with most of these sulfonamides, and against hCA XII with some of the new compounds. These compounds were generally less effective inhibitors of hCA II. Being membrane impermeant, these positively-charged sulfonamides are interesting candidates for targeting the tumor-associated CA IX and XII, as possible diagnostic tools or therapeutic agents.

Synthesis and biological evaluation of new 4-thiazolidinone derivatives

A series of new 2-aryl-4-thiazolidinones (3 and 4) was synthesized from 2-hydroxy-2,2-diphenyl-N’-[(substituted phenyl)methylene]acetohydrazides (2) and mercaptoacetic acid or 2-mercaptopropionic acid. The antimycobacterial activity of these compounds was determined and several leads with 95–99% inhibition at 6.25 μg/mL test concentration were identified. In addition, antitumor activities were measured against several tumor cell lines, and significant growth inhibition was observed for compound 4p. Taken together, 2-aryl-4-thiazolidinones were shown to be promising scaffolds for both antimycobacterial and tumor-targeting compounds.

N-(2,6-Dimethyl-3-oxo-1-thia-4-aza­spiro­[4.5]dec-4-yl)-2-hydr­oxy-2,2-di­phenyl­acetamide

In the title compound, C24H28N2O3S, the pendant methyl C atom bonded to the cyclohexane ring is disordered over two sites in a 0.580 (11):0.420 (11) ratio. The cyclohexane ring adopts a distorted chair conformation while the thiazolidine ring has an envelope conformation. The two phenyl rings make a dihedral angle of 71.8 (2)° with each other. The conformation is stabilized by an intramolecular N—H⋯O hydrogen bond. In the crystal structure, an intermolecular hydrogen bond O—H⋯O occurs.