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Three 1-aminoindanes, four anilines and BnOH or t-BuOH were reacted with chlorosulfonyl isocyanate to give sulfamoyl carbamates. Pd-C catalysed hydrogenolysis reactions of carbamates or deprotection of the Boc group of the carbamates with CF3 CO2 H afforded seven novel sulfamides. Human carbonic anhydrase (hCA) isoenzymes I and II (hCA I and hCA II) were purified from fresh human blood erythrocytes with one-step affinity chromatography on Sepharose 4B-tyrosine-sulfanilamide. The inhibitory properties of the novel sulfamides on both isoenzymes were determined using the esterase activity with 4-nitrophenyl acetate (NPA) as substrate. The tested novel sulfamides derived from 1-aminoindanes and anilines effectively inhibited hCA I and II competitively in the nanomolar range. Among these compounds, the novel sulfamide derivative 17 showed the most potent inhibitory effect against hCA I (Ki : 153.88 nM), while sulfamide derivative 26 showed the highest inhibitory potential against hCA II (Ki : 117.80 nM).

Six sulfonamides derived from indanes and tetralines were synthesized. The human carbonic anhydrase isozymes hCA I and hCA II inhibition effects of the synthesized sulfonamides were determined. From these compounds, while N-(5,6-dimethoxy-2,3-dihydro-1H-inden-2-yl) methane sulfonamide showed the most potent inhibitory effect against hCA I (K i ¼ 46 AE 5.4 mM, r 2 ¼ 0.978), N-(1,2,3,4-tetrahydronaphthalene-2-yl)methanesulfonamide was found to have the best inhibitory effect against hCA II (K i ¼ 94 AE 7.6 mM, r 2 ¼ 0.982).

Here, we provide an alternative synthesis of the natural bromophenol 3,4-dibromo-5-(2,3-dibromo-4,5-dihydroxybenzyl)-6-(ethoxymethyl)benzene-1,2-diol (3) and the first synthesis of (4,5-dihydroxy-2-methylphenyl)(3,4-dihydroxyphenyl)methanone (18) and its brominated derivatives 19-21. The compounds were characterized and tested against the two most studied members of the pH regulatory enzyme family, carbonic anhydrase (CA). The inhibitory potencies of the novel compounds and two natural bromophenols 2, 3 were analyzed at the human isoforms hCA I and hCA II as targets and the KI values were calculated. The KI values of the novel compounds were measured in the range of 13.7-32.7 mM for the hCA I isozyme and 0.65-1.26 mM for the hCA II isozyme. The structurally related compound 14 was also tested in order to understand the structure–activity relationship, and the clinically used sulfonamide acetazolamide (AZA)was tested for comparison reasons. All of the compounds exhibited competitive inhibition with 4-nitrophenylacetate as substrate. The compounds showed strong inhibitory activity against hCA I, being more effective as compared to the clinically used AZA (KI: 36.2 mM), but rather less activity against hCA II.

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.tr) 3,4-Dibromo-5-[2-bromo-3,4-dihydroxy-6-(methoxymethyl)benzyl]benzene-1,2-diol (2), a natural product, has been synthesized for the first time starting from (3-bromo-4,5-dimethoxyphenyl)methanol (5) in five steps and with an overall yield of 34%. The reaction of some methoxymethyl-substituted aryl methyl ethers with BBr 3 , followed by the addition of MeOH, afforded the corresponding methoxymethyl-substituted arylphenols in high yields.

A series of carbamate derivatives were synthesized and their carbonic anhydrase I and II isoenzymes and acetylcholinesterase enzyme (AChE) inhibitory effects were investigated. All carbamates were synthesized from the corresponding carboxylic acids via the Curtius reactions of the acids with diphenyl phosphoryl azide followed by addition of benzyl alcohol. The carbamates were determined to be very good inhibitors against for AChE and hCA I, and II isoenzymes. AChE inhibition was determined in the range 0.209-0.291 nM. On the other hand, tacrine, which is used in the treatment of Alzheimer's disease possessed lower inhibition effect (K i : 0.398 nM). Also, hCA I and II isoenzymes were effectively inhibited by the carbamates, with inhibition constants (K i ) in the range of 4.49-5.61 nM for hCA I, and 4.94-7.66 nM for hCA II, respectively. Acetazolamide, which was clinically used carbonic anhydrase (CA) inhibitor demonstrated K i values of 281.33 nM for hCA I and 9.07 nM for hCA II. The results clearly showed that AChE and both CA isoenzymes were effectively inhibited by carbamates at the low nanomolar levels.