Basic Science Sector

Pyrazolo[1,5?a]pyrimidine, [1,2,4]triazolo[1,5?a]-pyrimidine and pyrimido[1,2?a] benzimida?zole derivatives were synthesized by reaction of sodium salt of 3?hydroxy?(1?pyridin?2? yl)prop?2?en?1?one or sodium salt of 3?hydroxy?1?(pyridin?3?yl)prop?2?en?1?one with different heterocyclic amines in piperidenium acetate. Also,

A series of new 8-arylhydrazono-2-(benzylsulfanyl)-7H-purin-6-ones 6 were synthesized, their electronic absorption spectra in different organic solvents of varying polarities were investigated and their acid dissociation constants in both the ground and excited states were determined spectrophotometrically. The tautomeric structures of such products were elucidated by spectral analyses and correlation of their acid dissociation constants with the Hammett equation. The results indicated that the studied compounds 6 exist predominantly in the hydrazone tautomeric form 6A in both the ground and excited states.

Ethyl 2-acrylamido-4,5,6,7-tetrahydrobenzo [b] thiophene-3-carboxylate (ETTCA) has been synthesized and its structure has been elucidated by elemental analysis and spectral tools. Free radical polymerization of (ETTCA) has been conducted in several solvents using azobisisobutyronitrile (AIBN) as an initiator.

3-Acetyl[1,2,4]triazolo[3,4-a]isoquinolines were prepared using chitosan as a catalyst. These compounds were used to prepare a novel series of enaminones 5, and their reactions with hydrazonoyl halides 1 and 11 gave triazoloisoquinolines 8 and 13, respectively, with a carbonylpyrazole side chain. Hydrazinolysis of 8 and 13 gave the pyrazolopyridazines 10 and pyrazolopyridazinones 14. Reaction of 5 with hydroximoyl halides 15 led to triazoloisoquinoline 16 with a carbonylisoxazole side chain. Antibacterial effects of compounds 8 and 10 were studied.

The Schiff bases of N2O2 dibasic ligands, H2La and H2Lb are prepared by the condensation of ethylenediamine (a) and trimethylenediamine (b) with 6-formyl-7-hydroxy-5-methoxy-2-methylbenzopyran-4-one. Also tetra basic ligands, H4La and H4Lb are prepared by the condensation of aliphatic amines (a) and (b) with 6-formyl-5,7-dihydroxy-2-methylbenzopyran-4-one. New complexes of H4La and H4Lb with metal ions Mn(II), Ni(II) and Cu(II) are synthesized, in addition Mn(II) complexes with ligands H2La and H2Lb are also synthesized. Elemental and thermal analyses, infrared, ultraviolet-visible as well as conductivity and magnetic susceptibility measurements are used to elucidate the structure of the newly prepared metal complexes. The structures of copper (II) complexes are also assigned based upon ESR spectra study. All the complexes separated with the stoichiometric ratio (1:1) (M:L) except Mn-H4La and Mn-H4Lb with (2:1) (M:L) molar ratio. In metal chelates of the type 1:1 (M:L), the Schiff bases behave as a dinegative N2O2 tetradentate ligands. Moreover in 2:1 (M:L) complexes, the Schiff base molecules act as mono negative bidentate ligand and binuclear complex is then formed. The Schiff bases were assayed by the disc diffusion method for antibacterial activity against Staphylococcus aureus and Escherichia coli. The antifungal activity of the Schiff bases was also evaluated against the fungi Aspergillus flavus and Candida albicans.

Schiff base (L) ligand is prepared via condensation of pyridine-2,6-dicarboxaldehyde with 2-aminopyridine. The ligand and its metal complexes are characterized based on elemental analysis, mass, IR, solid re?ectance, magnetic moment, molar conductance, and thermal analyses (TG, DTG and DTA). The molar conductance reveals that all the metal

New 5-(9H-Fluoren-9-ylidene)- and 5-(1H-indan-1-ylidene)-2-thioxo-4-thiazolidinones 3a,b were synthesized Eco-friendly under microwave irradiation(MWI). These compounds undergo alkaline hydrolysis to afford thecorresponding thiol derivatives 4a,b, which cyclized into polysubstituted thiazoles 6a-h using arylazomalononitriles 5a-d as nucleophilic agents. Some selected products were tested for their antimicrobial activities. The equilibrium geometries of the studied compounds were calculated at the B3LYP/6-31G(d) level of the density functional theory (DFT). Conformational analysis has been carried out to determine the most stable conformers. The relative stability of the azo and hydrazo tautomers has been investigated. The HOMO-LUMO energy gap is used in rationalizing the reactivity of the studied compounds.

Published data over the last years on the methods of synthesis and biological applications of azolylthiazoles are reviewed here for the first time till 2011. The review was classified according to the type of azole ring linked to thiazole.

The antioxidant and anticancer activities of Syzygium cumini fruit extracts were investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay and viability of leukemia cancer cells (AML cell line) respectively. The successive extracts, hexane, chloroform, ether, ethyl acetate, ethanol and water were prepared and subjected to antioxidant and anticancer evaluation. The results showed that the ethanol extract had stronger antioxidant and anti- leukemia activities than the other ones. Spectroscopic methods data of active ingredients separated from ethanol extract indicated that S.cumini fruit extracts contained phenolic compounds, such as Kaempferol 7-O-methylether and sterols such as ?-Sitosterol responsible for their antioxidant and anticancer activities.

A simple, rapid and sensitive extractive spectrophotometric method has been developed for the assay ofsildenafil citrate (SILC) in pure and pharmaceutical formulations (Virecta tablets). This method is based on theformation of chloroform soluble ion-pair of SILC with bromothymol blue (BTB) and methylene chloride soluble ionpairof SILC with bromophenol blue (BPB) and eriochrome blue black R (EBBR) in borax buffer of pH 3 and volume1mL for BTB while acetate buffer of pH 3 and volume 1mL for BPB and universal buffer of pH 2 and volume 1.5 mLfor EBBR with absorption maximum at 415, 420 nm and 510 nm for BTB, BPB and EBBR reagents, respectively.

Cyrenaica is the largest phytogeographical region in Libya. The region holds Al-Jabal Al-Akhdar (the Green Mountain)landscape with the richest vegetation and highest species diversity in the country. Field study of the vegetation was carriedout in the different habitat types representing the mountainous landscape. Data were analyzed by Detrended Correspondence analysis (DCA) and Canonical Correspondence Analysis (CCA) against the environmental variables. Vegetation and speciesrichness varied with altitude from the sea level, through mid elevation slope vegetation in wadis, to herbaceous and lowshrub-vegetation towards the mountain top. Vegetation is classified into three major groups: (1) coastal and low altitudevegetation dominated by shrubs and trees which constitute about 60% of the plant life forms; (2) mid altitude and wadivegetation with the highest species richness and dominated by shrubs and trees which constitute over 60% of the plant lifeforms; and (3) mountain top vegetation dominated by herbs and few low shrubs constituting up to 90% of the plant lifeforms. The altitude, aspect and soil parameters do not explain the majority of variance in the obtained data which reveal thatother diverse local conditions and habitat types seem to be the main determinant of vegetation variation in Al-Jabal Al-Akhdar landscape.