Yusuf M. Al-Hiari

Synthesis and Antibacterial Properties of New 8-Nitrofluoroquinolone Derivatives

The objective of this research was the preparation of new 8-nitrofluoroquinolone models and investigation of their antibacterial properties. The work initially involved large scale preparation of the synthon 7-chloro-1-cyclopropyl-6-fluoro-8-nitro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (3), followed by introduction of substituted primary amine appendages at the C-7 position to give derivatives 9a-g, in which the amino group is appended to substituted benzenes or aromatic heterocycles, is part of a primary alpha-amino acid or just a simple primary aliphatic amine. This nucleophilic aromatic substitution step was a very simple procedure since the 8-nitro group of the above synthon facilitated the addition of weak nucleophiles at C-7. All compounds prepared were fully identified and characterized using NMR, IR, EA and MS, and were consistent with expected structures. The prepared targets and the intermediates have shown interesting antibacterial activity against gram positive and/or gram negative strains. In particular, the p-toluidine, p-chloroaniline and aniline derivatives showed good activity against S. aureus with MIC range approximately 2-5 microg/mL. In conclusion, more lipophilic groups seem to enhance activity against gram positive strains.

Formulation and In Vitro Evaluation of Xanthan Gum or Carbopol 934-Based Mucoadhesive Patches, Loaded with Nicotine

Bilayer nicotine mucoadhesive patches were prepared and evaluated to determine the feasibility of the formulation as a nicotine replacement product to aid in smoking cessation. Nicotine patches were prepared using xanthan gum or carbopol 934 as a mucoadhesive polymers and ethyl cellulose as a backing layer. The patches were evaluated for their thickness, weight and content uniformity, swelling behavior, drug–polymers interaction, adhesive properties, and drug release. The physicochemical interactions between nicotine and the polymers were investigated by Fourier transform infrared (FTIR) spectroscopy. Mucoadhesion was assessed using two-arm balance method, and the in vitro release was studied using the Franz cell. FTIR revealed that there was an acid base interaction between nicotine and carbopol as well as nicotine and xanthan. Interestingly, the mucoadhesion and in vitro release studies indicated that this interaction was strong between the drug and carbopol whereas it was weak between the drug and xanthan. Loading nicotine concentration to non-medicated patches showed a significant decrease in the mucoadhesion strength of carbopol patches and no significant effect on the mucoadhesion strength of xanthan patches. In vitro release studies of the xanthan patches showed a reasonable fast initial release profile followed by controlled drug release over a 10-h period.

Synthesis and characterization of polycarbonates by melt phase interchange reactions of alkylene and arylene diacetates with alkylene and arylene diphenyl dicarbonates.

This work presents a new synthetic approach to aromatic and aliphatic polycarbonates by melt polycondensation of bisphenol A diacetates with alkylene- and arylenediphenyl dicarbonates. The diphenyl dicarbonates were prepared from phenyl chloroformate and the corresponding dihydroxy compounds. The process involved a precondensation step under a slow stream of dry argon with the elimination of phenyl acetate, followed by melt polycondensation at high temperature and under vacuum. The potential of this reaction is demonstrated by the successful synthesis of a series of aromatic-aromatic and aromatic-aliphatic polycarbonates having inherent viscosities from 0.19 to 0.43 dL/g. Thus low to intermediate molecular mass polymers were obtained. The 13C-NMR spectra of the carbon of the carbonate group showed that the formed polycarbonates contain partial random sequence distribution of monomer residues in their chains. The polycarbonates were characterized by inherent viscosity, FTIR, 1H-NMR and 13C-NMR spectroscopy. The glass transition temperatures, measured by DSC, of the polycarbonates were in the range 13–108 °C. The thermogravimetric curves of showed that these polymers have good thermal stability up to 250 °C. The present approach may open the door for novel polycarbonates containing other organic functional groups.

Synthesis and anti-hyperlipidemic evaluation of N‑(benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide derivatives in Triton WR-1339-induced hyperlipidemic rats.

The lipid-lowering activity of a series of novel N-(benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide derivatives has been studied in Triton WR-1339-induced hyperlipidemia in rats. The test animals were divided into four groups: control, hyperlipidemic, compound + 4% DMSO [C1: N-(2-benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide (1), C2: N-(3-benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide (2), C3: N-(4-benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide (3)]-treated and bezafibrate (BF)-treated. At a dose of 15 mg/Kg body weight, compounds 2, 3 and BF significantly reduced elevated plasma triglycerodes levels after 12 h. Moreover, high density lipoprotein-cholesterol levels were significantly increased in all treated groups after 12 h compared to the hyperlipidemic control group, except for C1 which was inactive. In sum, it may be stated that the results of the present study demonstrated new properties of some N-(benzoylphenyl)-5-fluoro-1H-indole-2-carboxamide derivatives as potent lipid lowering agents and these beneficial activities may contribute to their cardioprotective and antiatherosclerotic role.

The hypolipidemic activity of novel benzofuran-2- carboxamide derivatives in Triton WR-1339-induced hyperlipidemic rats: a comparison with bezafibrate

Using Triton WR-1339-induced hyperlipidemic rats as an experimental model, we investigated whether compound 4 [N-(9,10-dihydro-9,10-dioxoanthracen-2-yl)bezofuran-2-carboxamide] and compound 5 [N-(4-benzoylphenyl)benzofuran-2-carboxamide], two novel anti-hyperlipidemic agents, have any effect on plasma triglyceride (TG), total cholesterol (TC), and high-density lipoprotein cholesterol levels (HDL-C) levels. The tested animals were divided into control (CG), hyperlipidemic (HG), and compounds 4, 5, and bezafibrate (BF) treated groups. At a dose of 15 mg/kg body weight, compounds 4, 5, and BF significantly reduced elevated plasma TG levels after 7 and 24 h. Furthermore, HDL-C levels were remarkably increased in all treated groups after 7 and 24 h compared to the hyperlipidemic control group. However, only compounds 4 and 5 treated groups clearly showed a significant reduction in plasma total cholesterol levels after 7 and 24 h. It is therefore reasonable to assume that compounds 4 and 5 may have promising potential in the treatment of hyperlipidemia and atherosclerosis.

Antihyperlipidemic Properties of Novel N-(Benzoylphenyl)-5-substituted-1H-indole-2-carboxamides in Triton WR-1339-Induced Hyperlipidemic Rats

In the search for new potential antihyperlipidemic agents, the present study focuses on the synthesis of novel N-(benzoylphenyl)-5-substituted-1H-indole-2-carboxamides (compounds 8-12, 15, 16, 18) and investigating their antihyperlipidemic activity using Triton WR-1339-induced hyperlipidemic rats as an experimental model. Hyperlipidemia was developed by intraperitoneal injection of Triton WR-1339 (250 mg/kg body weight). The tested animals were divided into normal control (NCG), hyperlipidemic (HG), compound 8, 9, 15, 16, 18- and bezafibrate treated groups. At a dose of 15 mg/kg body weight, compounds 9, 16, 18 and bezafibrate (100 mg/kg) significantly (p < 0.0001) reduced elevated plasma triglycerides levels after 12 h compared to the hyperlipidemic control group. However, only the group treated with compounds 9, 16 and 18 showed an obviously significant (p < 0.001) reduction in plasma total cholesterol levels after 12 h compared to the hyperlipidemic control group. Moreover, high density lipoprotein-cholesterol levels were significantly (p < 0.0001) increased in all treated groups after 12 h compared to the hyperlipidemic control group, except for compounds 8 and 15 which revealed inactive. It is therefore reasonable to assume that compounds 9, 16 and 18 may have potential in the treatment of hyperlipidemia.

Pharmacological evaluation of novel indole-2-carboxamides as potent lipid-lowering agents in Triton-WR-1339-induced hyperlipidemic rats.

The lipid-lowering effects of two novel antihyperlipidemic agents, BMI2C [N-(4-benzoylphenyl)- 5-methoxy-1H-indole-2-carboxamide] and DDMI2C [N-(9,10-dihydro-9,10-dioxoanthracen- 2-yl)-5-methoxy-1H-indole-2-carboxamide], were studied using hyperlipidemic rats as an experimental model; hyperlipidemia was developed by intraperitoneal injection of Triton WR-1339 (200 mg/kg body weight). At a dose of 15 mg/kg body weight, BMI2C and DDMI2C signifi cantly reduced elevated plasma triglyceride levels after 7 and 24 h. Furthermore, BMI2C and DDMI2C significantly reduced elevated plasma total cholesterol levels after 24 h. Interestingly, high-density lipoprotein-cholesterol levels were significantly increased in all treated groups. These findings indicate that the two studied novel compounds have a promising potential in the treatment of hyperlipidemia and atherosclerosis

Heterocycles [h]-fused onto 4-oxoquinoline-3-carboxylic acid, part VIII [1]. Convenient synthesis and antimicrobial properties of substituted hexahydro[1,4]diazepino[2,3-h]quinoline-9-carboxylic acid and its tetrahydroquino[7,8-b]benzodiazepine analog.

[1,4]Diazepino[2,3-h]quinolone carboxylic acid 3 and its benzo-homolog tetrahydroquino[7,8-b]benzodiazepine-3-carboxylic acid 5 were prepared via PPA-catalyzed thermal lactamization of the respective 8-amino-7-substituted-1,4-dihydro-quinoline-3-carboxylic acid derivatives 8, 10. The latter compounds were obtained by reduction of their 8-nitro-7-substituted-1,4-dihydroquinoline-3-carboxylic acid precursors 7, 9 which, in turn, were prepared by reaction of 7-chloro-1-cyclopropyl-6-fluoro-8-nitro-1,4-dihydroquinoline-3-carboxylic acid (6) with each of β-alanine and anthranilic acid. All intermediates and target compounds were characterized using elemental analysis, NMR, IR and MS spectral data. The prepared targets and the intermediates have shown interesting antibacterial activity mainly against Gram positive strains. In particular, compound 8 showed good activity against S. aureus (MIC = 0.39 µg/mL) and B. subtilis (MIC = 0.78 µg/mL). Compounds 5a and 9 have also displayed good antifungal activity against C. albicans (MIC = 1.56 µg/mL and 0.78 µg/mL, respectively). None of the compounds tested showed any anticancer activity against solid breast cancer cell line MCF-7 cells or a human breast adenocarcinoma cell line.

Synthesis and Pharmacological Evaluation of Novel Substituted and Unsubstituted N-(Benzoylphenyl)-1H-indole-2-carboxamides as Potent Antihypertriglyceridemic Agents

The N-(benzoylphenyl)-1H-indole-2-carboxamide derivatives 1 - 6 were synthesized, and the lipid-lowering effects of two of these novel compounds were studied using hyperlipidemic rats as an experimental model. Treatment of ethyl-1H-indole-2-carboxylate with aminobenzophenones in the presence of sodium ethoxide and DMF, followed by purifi cation using column chromatography, gave the target compounds in good yields. The tested animals were divided into control, hyperlipidemic, compounds 2-, 3- and bezafibrate-treated groups. At a dose of 15 mg/kg body weight, compounds 2, 3 and bezafibrate significantly reduced the elevated plasma triglyceride levels after 7 and 24 h. Furthermore, the high-density lipoprotein- cholesterol levels were remarkably increased in all treated groups after 7 and 24 h compared to the hyperlipidemic control group. However, only compounds 2- and 3-treated groups obviously showed a significant reduction in plasma total cholesterol levels after 24 h. It is therefore reasonable to assume that 2 and 3 may have a promising potential in the treatment of hyperlipidemia and coronary heart diseases.

Evaluation of vanillic acid as inhibitor of carbonic anhydrase isozyme III by using a modified Hummel–Dreyer method: approach for drug discovery

α-3 carbonic anhydrase isozyme (CAIII) is the most abundant protein in adipocytes and considered insensitive to sulfonamide inhibitors. It was reported recently that the knock-down of CAIII is attributed with controlling lipogenesis. Thus inhibition of this target may lead to the discovery of new therapies against obesity and insulin resistance. Vanillic acid as a small molecule with coordinating groups and has a potential to bind zinc atoms in CA binding sites. Inhibition of CAIII by vanillic acid was evaluated by Hummel-Dreyer chromatography because it provides free interaction between ligand and macromolecule and introduces solution for faulty results obtained by current colorimetric assays. HPLC system of vanillic acid produces vacancy (negative) peak representing the amount of attached vanillic acid with CAIII. It was found that vanillic acid is able to bind with CAIII through two equilibria, one at equimolar ratio and another at 2:1 (vanillic acid-CAIII) ratio. The affinity constant of equimolar binding between CAIII and vanillic acid was found to be 14,400 m(-1) . It was found that vanillic acid binding with CAIII is much stronger than phenol and acetazolamide (positive controls).