Mousa Al-Smadi

New 1,2,3-selenadiazole and 1,2,3-thiadiazole derivatives.

New 1,2,3-thiadiazole and 1,2,3-selenadiazole derivatives, 14-23, were prepared from the ketones 1-5 via the corresponding semicarbazones or hydrazones 6-12. The Hurd-Mori and Lalezari methods were used, respectively, for the preparation of these 1,2,3-thiadiazole and 1,2,3-selenadiazole derivatives. The intermediate 13 was also trapped, separated and fully characterized. These derivatives are important for photocrosslinking processes and due to their potential biological activity.

Synthesis, Characterization and Antimicrobial Activity of New 1,2,3-Selenadiazoles

The commercially available aromatic polyketones 1a-d were utilized for the synthesis of the multi-arm1,2,3-selenadiazole derivatives 3a-d. The preparation starts with the reaction between compounds 1a-d and p-toluenesulfonyl hydrazide to give the corresponding tosylhydrazones 2a-d. Subsequent reaction with selenium dioxide leads to regiospecific ring closure of the tosylhydrazones to give the target multi-arm 1,2,3-selenadiazole derivatives in high yield. A 1,2,3-selenadiazole derivative 3e containing an epoxide ring was also prepared. The structures of all the synthesized compounds were confirmed on the basis of spectral and analytical data. The compounds were screened in vitro for their antimicrobial activity against various pathogenic bacterial and Candida strains obtained from King Abdullah Hospital in Irbid -Jordan. Compounds 3a, 3c and 3e were found to be highly active against all the selected pathogens. Compound 3e showed an inhibition zone of 13 mm against the highly resistant P. aruginosa.

New multi-1,2,3-selenadiazole aromatic derivatives.

The aromatic polyketones 3a-d are versatile compounds for the synthesis of the multi-1,2,3-selenadiazole aromatic derivatives 1a-d. The preparation starts with the reaction between the multi-bromomethylene benzene derivatives 2a-d and 4-hydroxy-acetophenone to give compounds 3a-d which are transformed through the reaction with semicarbazide hydrochloride or ethyl hydrazine carboxylate into the corresponding semicarbazones derivatives 4a-d or hydrazones 5a-d. The reaction with selenium dioxide leads to regiospecific ring closure of semicarbazones or hydrazones to give the multi-1,2,3-selenadiazole aromatic derivatives in high yield.

Synthesis, antimicrobial and in vitro antitumor activities of a series of 1,2,3-thiadiazole and 1,2,3-selenadiazole derivatives

Three derivatives of substituted 1,2,3-thia- or 1,2,3-selenadiazole (4a–c) were prepared and characterized by different chemical techniques. These compounds were evaluated for their antimicrobial and antitumor activities. Compounds 4a (propenoxide derivative), 4b (carbaldehyde derivative), and 4c (benzene derivative) were active against the yeast-like fungi Candida albicans. Compound 4a was active against gram-negative Escherichia coli, and compound 4c was active against the gram-positive Staphylococcus aureus. For the antitumor activity, both compounds 4b and 4c were active against all tested tumor cell lines, namely, SW480, HCT116, C32, MV3, HMT3522, and MCF-7. The activity of compound 4c was greater than that of compound 4b and more than that of the reference antitumor 5-flourouracil against the SW480, HCT116, and MCF-7 tumor cell lines. In conclusion, a number of the prepared 1,2,3-thia- or 1,2,3-selenadiazole compounds showed promising antifungal, antibacterial, and in vitro antitumor activities. Further investigations are required to explore the mechanism by which active compound are inducing their cytotoxicity.

Study of the antibacterial and antifungal activities of synthetic benzyl bromides, ketones, and corresponding chalcone derivatives.

Several applications of chalcones and their derivatives encouraged researchers to increase their synthesis as an alternative for the treatment of pathogenic bacterial and fungal infections. In the present study, chalcone derivatives were synthesized through cross aldol condensation reaction between 4-(N,N-dimethylamino)benzaldehyde and multiarm aromatic ketones. The multiarm aromatic ketones were synthesized through nucleophilic substitution reaction between 4-hydroxy acetophenone and benzyl bromides. The benzyl bromides, multiarm aromatic ketones, and corresponding chalcone derivatives were evaluated for their activities against eleven clinical pathogenic Gram-positive, Gram-negative bacteria, and three pathogenic fungi by the disk diffusion method. The minimum inhibitory concentration was determined by the microbroth dilution technique. The results of the present study demonstrated that benzyl bromide derivatives have strong antibacterial and antifungal properties as compared to synthetic chalcone derivatives and ketones. Benzyl bromides (1a and 1c) showed high ester activity against Gram-positive bacteria and fungi but moderate activity against Gram-negative bacteria. Therefore, these compounds may be considered as good antibacterial and antifungal drug discovery. However, substituted ketones (2a–b) as well as chalcone derivatives (3a–c) showed no activity against all the tested strains except for ketone (2c), which showed moderate activity against Candida albicans.

GABA metabolism and ROS induction in lentil (Lens culinaris Medik) plants by synthetic 1,2,3-Thiadiazole compounds

In this study, we investigated the physiological effects of three synthetic 1,2,3-thiadiazole compounds (compound I: 4-[1,2,3]-Thiadiazole-4-yl-phenol, compound II: 1,3-Bis[4-(1,2,3-thiadiazol-4-yl)phenoxy]propane, compound III: 4-(4-{2,3,4,5,6-Penta[4-(1,2,3-thiadiazole-4-yl)phenoxymethyl]benzyloxy}phenyl)-1,2,3-thiadiazole) treatments on plants via the characterization of γ-aminobutyric acid metabolite level, the accumulation of reactive oxygen species (ROS), total protein contents, total carbohydrate contents, fresh weight and dry mass in two lentil (Lens culinaris Medik) cultivars (Jordan 1 and Jordan 2). In response to the three synthetic 1,2,3-thiadiazole compounds (I, II and III) treatments. A significant increase in γ- aminobutyric acid (GABA) and malondialdehyde (MDA) levels and a significant reduction in carbohydrates and protein levels and fresh weight and dry mass were obtained in both lentil cultivars. Jordan 2 cultivar showed the highest GABA and MDA accumulation and significant reduction in the carbohydrate and protein levels under the various thiadiazole compounds treatments. This suggests that GABA molecule may act as a defense mechanism and signaling molecule in carbohydrate metabolism and other physiological systems in lentil. In conclusion, our results revealed that the synthetic 1,2,3-thiadiazole compound ІІ (1,3-Bis[4-(1,2,3-thiadiazol-4-yl)phenoxy]propane) had the strongest physiological inhibitory effect on lentil.

Thermogravimetric and composition analysis of Jordanian oil shale

ABSTRACT Jordan occupies the eighth place in oil shale reserve in the world. Prospective efforts are directed toward the production of fuel from shale. Analysis of oil shale samples will help in planning for energy strategies. Oil shale samples were collected from Wadi Ash Shallala at Yarmouk Basin. X-ray fluorescence spectrometer and X-ray diffraction showed that calcite is the dominant mineral. Other minerals such as; Kaolinite, quartz, and Fluorapatite, were detected. Thermogravimetric analysis revealed that mass loss is due to organic matter decomposition at 350–550°C and carbonate and silicate decomposition at 650–850°C. Fourier transform infrared analysis revealed the main organic groups.