Benzenesulfonamides incorporating bulky aromatic/heterocyclic tails with potent carbonic anhydrase inhibitory activity.

Three series of sulfonamides incorporating long, bulky tails were obtained by applying synthetic strategies in which substituted anthranilic acids, quinazolines and aromatic sulfonamides have been used as starting materials. They incorporate long, bulky diamide-, 4-oxoquinazoline-3-yl- or quinazoline-4-yl moieties in their molecules, and were investigated for the inhibition of four physiologically relevant carbonic anhydrase (CA, EC 4.2.1.1) isoforms, the cytosolic human (h) hCA I and II, as well as the transmembrane hCA IX and XII. Most of the new sulfonamides showed excellent inhibitory effects against the four isoforms, with KIs of 7.6-322nM against hCA I, of 0.06-85.4nM against hCA II; of 6.7-152nM against hCA IX and of 0.49-237nM against hCA XII; respectively. However no relevant isoform-selective behavior has been observed for any of them, although hCA II and XII, isoforms involved in glaucoma-genesis were the most inhibited ones. The structure-activity relationship for inhibiting the four CAs with these derivatives is discussed in detail.

A new class of quinazoline-sulfonamides acting as efficient inhibitors against the α-carbonic anhydrase from Trypanosoma cruzi.

The protozoan parasite Trypanosoma cruzi is the agent responsible for trypanosomiasis (Chagas disease) in humans and other animals. It has been recently reported that this pathogen encodes for an α-class carbonic anhydrase (CA, EC 4.2.1.1), denominated TcCA, which was shown to be crucial for its life cycle. Inhibition studies of a class of 4-oxoquinazoline containing a benzensulfonamide moiety and their 4-thioxo bioisosteres against the protozoan enzyme TcCA are described here. Most of 4-oxoquinazoline sulfonamides showed nanomolar TcCA inhibition activity with K(I)s in the same order of magnitude of acetazolamide (AAZ), whereas their thioxo bioisosters showed moderate anti-Trypanosoma CA potency with K(I)s in the micromolar range. The discovery of compounds incorporating a 4-oxoquinazoline ring as a low-nanomolar TcCA inhibitor is quite promising and it may be useful for developing anti-Trypanosoma agents with a novel mechanism of action compared to the clinically used drugs (such as benznidazole, nifurtimox) for which significant resistance and serious adverse effects due to their high-toxicity appeared.

Inhibition of carbonic anhydrases from the extremophilic bacteria Sulfurihydrogenibium yellostonense (SspCA) and S. azorense (SazCA) with a new series of sulfonamides incorporating aroylhydrazone-, [1,2,4]triazolo[3,4-b][1,3,4]thiadiazinyl- or 2-(cyanophenylmethylene)-1,3,4-thiadiazol-3(2H)-yl moieties.

A series of new sulfonamides was prepared starting from 2-oxo-N'-(4-sulfamoylphenyl)-propanehydrazonoyl chloride, a sulfanilamide derivative, which was reacted with aroylhydrazides, amines, or thiols. A library of derivatives incorporating aroylhydrazone, [1,2,4]triazolo[3,4-b][1,3,4]thiadiazinyl- or 2-(cyanophenyl-methylene)-1,3,4-thiadiazol-3(2H)-yl moieties was thus synthesized. The new compounds were investigated as inhibitors of four α-carbonic anhydrases (CAs, EC 4.2.1.1), the human (h) isoforms hCA I and II, and the bacterial ones recently isolated from the extremophilic bacteria Sulfurihydrogenibium yellostonense (SspCA) and Sulfurihydrogenibium azorense (SazCA). Low nanomolar activity was observed against hCA II (KIs of 0.56-17.1 nM) whereas hCA I was less inhibited by these compounds (K(I)s of 86.4 nM-32.8 µM). The bacterial CAs were also effectively inhibited by these derivatives (K(I)s in the range of 0.77-234 nM against SazCA, and of 6.2-89.1 against SspCA, respectively), with several low nanomolar/subnanomolar inhibitors detected against both of them. As SspCA and SazCA are among the most thermostable and catalytically active CAs, it is of interest to find modulators of their activity for potential biotechnologic applications.

Carbonic anhydrase inhibitors. Benzenesulfonamides incorporating cyanoacrylamide moieties strongly inhibit Saccharomyces cerevisiae ß-carbonic anhydrase.

A series of benzenesulfonamides incorporating cyanoacrylamide moieties (tyrphostine analogs) were assayed as inhibitors of the ß-carbonic anhydrase (CA, EC 4.2.1.1) from Saccharomyces cerevisiae, ScCA. Some of these compounds were low nanomolar or subnanomolar ScCA inhibitors and showed selectivity ratios in the range of 4.91-69.86 for inhibiting the yeast enzyme over the offtarget human (h) isoforms hCA I and of 6.46-13.52 for inhibiting ScCA over hCA II. The model organism S. cerevisiae and this particular enzyme may be useful for detecting antifungals with a novel mechanism of action compared to the classical azole drugs to which significant drug resistance emerged. Indeed, some of these sulfonamides inhibited the growth of the yeast with CC50-s in the range of 0.73-6.54 µM.

Anti-ulcerative colitis activity of compounds from Euphorbia granuleta Forssk.

The aim of the present study was to evaluate the anti-ulcerative colitis (UC) activity of the total alcohol extracts of Euphorbia granuleta Forssk. (Euphorpiaceae), isolate and identify the active compounds that could be responsible for the activity, in addition to determination of the possible mechanism of action. Six compounds were isolated and identified from this plant: three phenolic compounds (kampferol, kampferol-3-glucoside and kampferol-3-galactoside) in addition to three steroidal compounds (1-ethoxypentacosane, heptacosan-1-ol and ß-sitosterol). Three compounds (heptacosan-1-ol, ß-sitosterol and kampferol-3-galactoside) were found to be responsible for the anti-UC activity of E. granuleta extract. The anti-UC activity of these compounds may be explained by reducing the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α), in addition to reduction of colonic malondialdehyde (MDA) contents. No side effects were reported on liver and kidney functions. The active compounds reduced both serum TNF-α and mucosal MDA levels.

Carbonic anhydrase inhibitors: benzenesulfonamides incorporating cyanoacrylamide moieties are low nanomolar/subnanomolar inhibitors of the tumor-associated isoforms IX and XII.

A series of benzenesulfonamides incorporating cyanoacrylamide moieties (tyrphostine analogues) have been obtained by reaction of sulfanilamide with ethylcyanoacetate followed by condensation with aromatic/heterocyclic aldehydes, isothiocyanates or diazonium salts. The new compounds have been investigated as inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4. 2.1.1), and more specifically against the cytosolic human (h) isoforms hCA I and II, as well as the transmembrane, tumor-associated ones CA IX and XII, which are validated antitumor targets. Most of the new benzenesulfonamides were low nanomolar or subnanomolar CA IX/XII inhibitors whereas they were less effective as inhibitors of CA I and II. The structure-activity relationship for this class of effective CA inhibitors is also discussed. Generally, electron donating groups in the starting aldehyde reagent favored CA IX and XII inhibition, whereas halogeno, methoxy and dimethylamino moieties led to very potent CA XII inhibitors.

Quinazoline-tyrphostin as a new class of antitumor agents, molecular properties prediction, synthesis and biological testing.

A new series of substituted quinazolin-4-(3H)-one-tyrphostin derivatives was prepared and screened for their cytotoxic activity against three tumor cell lines, namely human breast cancer cell line (MCF-7), human cervical cancer cell line (HeLa) and human hepatocellular liver carcinoma cell line (HepG2) using the colorimetric MTT assay. Among the current series, 10 compounds exhibited remarkable in vitro antiproliferative activity against the three tested cell lines with the IC(50) values ranging from 0.009 to 0.015 mM. All the compounds showed suitable drug like characteristics according to Lipinski's rule.

The effect of four coffee types on normotensive rats and normal/hypertensive human volunteers.

Coffee is a commonly consumed beverage. The purpose of this study was to determine the effect of the four coffee types on blood pressure (BP). The caffeine percentage was tested on one cup (250 mL) of each type of coffee (Arabian, Turkish, American and an instant coffee preparation) using two methods. 65 adult male rats and 400 healthy human volunteers were used in this study. Normotensive rats were treated orally with a single dose of normal saline with varying types of coffee. Normotensive and mildly hypertensive human volunteers were administered a cup (250 mL) of any type of coffee separately. Tail cuff and a strain-gauge plethysmograph were used to measure the systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) of the rats, and volunteers, respectively before and 0.5, 1.0, 1.5, and 2 h post administration. The mean arterial pressure (MAP) was calculated mathematically using SBP and DBP. The alkaloidal percentage of different types of coffee showed the presence variable contents and amount of active materials. The study showed that Arabian, Turkish, American and instant coffee all have the potential to cause a BP lowering effect. Variable antimicrobial activities were recorded for the different types of coffee when tested bacteria.

Synthesis, analgesic and anti-inflammatory evaluation of some novel quinazoline derivatives.

Two series of some new 2,4,6-trisubstituted-quinazoline derivatives were prepared and screened for their analgesic, anti-inflammatory activity and acute toxicity. Four compounds were more potent analgesic agents than the reference drug Indomethacin and thirteen compounds showed significant anti-inflammatory activity. Seven compounds showed combined ability to inhibit both pain and inflammation. Compounds tested for acute toxicity showed no toxic symptoms or mortality rates 24 h post-administration implying their good safety margin.