Ahmed Abu-Rayyan

Synthesis, Structure and Reactions of 1,3-Dimethyl-5-bis(thiomethyl)methylenebarbituric Acid

1,3-Dimethyl-5-bis(thiomethyl)methylenebarbituric acid (8) is obtained from 1,3-dimethylbarbituric acid and CS2/NEt3 followed by alkylation with methyl iodide. Compound 8 reacts with aqueous ammonia to give 5-amino(thiomethyl)methylene-1,3-dimethylbarbituric acid (9). With benzylamine, the thiomethyl substituent in 9 is replaced to give 5-amino(benzylamino)methylene-1,3- dimethylbarbituric acid (10) while with methanesulfonic acid the sulfonate salt 11 is formed. The crystal structures of 8 and 9 are reported. Graphical Abstract Synthesis, Structure and Reactions of 1,3-Dimethyl-5-bis(thiomethyl)methylenebarbituric Acid

Immunomodulatory effect of Moringa peregrina leaves, ex vivo and in vivo study

This study was conducted to assess the in vivo and ex vivo immunomodulatory effect of the ethanol leaves extract of Moringa peregrina in Balb/c mice. For this study, five groups of 5 Balb/c mice were given a single acute subtoxic oral dose of the ethanolic extract at 1.13, 11.30, 23.40 and 113.4 mg/kg and the immunomodulatory effect was assessed on the 6th day following the ingestion. In the (non-functional) assessment, the effect of the extract on the body weight, relative lymphoid organ weight, splenic cellularity and peripheral blood hematologic parameters were evaluated. While in the immunomodulation assessment (functional), we investigated the effect of the extract on the proliferative capacity of splenic lymphocytes and peripheral T and B lymphocytes using mitogen blastogenesis, mixed allogeneic MLR and IgM-Plaque forming cells assays. The ingestion of M. peregrina extract caused a significant increase in the body weight, weight and number of cells of spleen and lymph nodes of the treated mice. Furthermore, the count of RBCs, WBCs, platelets, hemoglobin concentration and PCV % were increased by the extract treatment in a dose-dependent manner. M. peregrina enhanced the proliferative responses of splenic lymphocytes for both T cell and B-cell mitogens. Likewise, the mixed lymphocyte reaction MLR assay has revealed a T-cell dependent proliferation enhancement in the extract treated mice. Moreover, the oral administration of M. peregrina leaves extracts significantly increased PFCs/106 splenocytes in a dose-dependent manner. In conclusion, subtoxic acute doses of M. peregrina extract demonstrated significant potential as an immunomodulatory agent even at the lowest dose of 1.13 mg/kg.

C–H···O-Brückenbindungen in Imidazolium-Carboxylaten / C–H···O Hydrogen Bonds in Imidazolium Carboxylates

2,3-Dihydro-1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (1) reacts with benzoic acid to give the corresponding 1,3-diisopropyl-4,5-dimethylimidazolium benzoate salt 2. Similarly, 1,3-diisopropyl-4,5-dimethylimidazolium formiate (3) is obtained from 1 and ammonium formiate. In crystals of 2, the anions are linked to the imidazolium ions by monofunctional O···H-C bonds while in 3 bifurcated O・・・H-C bonds are observed. In 1,3-diisopropyl-4,5-dimethylimidazolium hydrogenoxalate (4), obtained from 1 and oxalic acid, hydrogen bonds connect both imidazolium ions to the hydrogenoxalate ions in a bifurcated mode as well as the anions to each other.

The Acetylacetonate Ion as its E/Z-Isomer in 1,3-Diisopropyl-4,5- dimethylimidazolium Acetylacetonate

1,3-Diisopropyl-4,5-dimethylimidazolium acetylacetonate (2) is obtained from 2,3-dihydro-1,3-diisopropyl-4,5-dimethylimidazol- 2-ylidene (1) and acetylacetone. Its crystal structure reveals the presence of ion pairs linked by C-H ··· O hydrogen bonds. In 2, the acetylacetonate ion adopts the structure of its E/Z-isomer (C).

Zur Strukturchemie von 2-Methylenimidazolinen [1]

The 2-methylenimidazolines ImC(CN)2 (6a - c, Im = 1,3-dialkyl-4,5-dimethylimidazol-2-ylidene) are prepared by the reaction of the imidazolium salts [ImBr]Br (5) and malodinitrile while ImC{C(O)Ph}2 (7) is obtained from ImCH2 (2) and benzoic fluoride. Both the structural data of 6b, 6c, and 7 and the 13C NMR data demonstrate the influence of steric and electronic effects on the charge separation and the nonplanar arrangement of the substituents attached at the carbon atoms of the central olefinic bond