Azhar-ul-Haq Ali Shah

Iodoxolone-Based Hypervalent Iodine Reagents

The fast access to simple (Z)-3-iodo acrylic acid derivatives which can be easily oxidized to the corresponding hypervalent iodine(III) reagents is described. They can be used for various reactions with superior or similar reactivity as conventional hypervalent iodine(III) reagents.

1,1-Diphenyl,2-picrylhydrazyl free radical scavenging, bactericidal, fungicidal and leishmanicidal properties of Teucrium stocksianum

In the present study, we evaluated the pharmacological and toxicological effects of Teucrium stocksianum. The crude extract of T. stocksianum (Ts.Cr) and its subsequent organic fractions: n-hexane (Ts.Hex), chloroform (Ts.CHCl3) and ethyl acetate (Ts.EtAc) exhibited 1,1-diphenyl,2-picrylhydrazyl free radical scavenging activity with different potencies. Ts.EtAc was found to be most potent. Ts.Cr, Ts.Hex, Ts.CHCl3 and Ts.EtAc showed significant bactericidal activity against Escherichia coli, Staphylococcus aureus, Salmonella typhi, Shigella flexneri and Bacillus subtilis at their extent. Ts.Cr, Ts.Hex, Ts.CHCl3 and Ts.EtAc displayed fungicidal action against Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus and Fusarium solani at various minimum inhibitory concentrations. Ts.Cr and Ts.EtAc exhibited marked inhibition of Leishmania tropica growth, observed after 48 and 96 hrs of treatment. These data indicate that the T. stocksianum methanolic extract and its resultant fractions possess antioxidant, antibacterial, antifungal and antileishmanial activities. Thus, the present research unearths the scientific base for T. stocksianum medicinal application as antioxidant and antimicrobial agents.

Heavy metals content, phytochemical composition, antimicrobial and insecticidal evaluation of Elaeagnus angustifolia

Elaeagnus angustifolia was analyzed for determination of metals, phytoconstituents, bactericidal, fungicidal and insecticidal effects and to explore its chemical and biological potential. The root, branches, leaves, stem bark and root bark parts of E. angustifolia were found to contain iron, lead, copper, cadmium, zinc, chromium, nickel and cobalt in different concentrations. Crude extract of Elaeagnus angustifolia (Ea.Cr) was tested positive for the presence of alkaloids, flavonoids, saponins and tannins. Ea.Cr and its fractions, n-hexane (Ea.Hex), ethyl acetate (Ea.EtAc) and aqueous (Ea.Aq) showed bactericidal activity against Escherichia coli and Staphylococcus aureus, while against Pseudomonas aeruginosa only Ea.Hex and Ea.EtAc were effective. When tested for antifungal effect, Ea.Cr exhibited fungicidal action against Aspergillus fumagatus, Ea.EtAc and Ea.Aq against Aspergillus flavis and Ea.EtAc against Aspergillus niger. Ea.Hex was active against all three fungal strains. The chloroform fraction (Ea.CHCl3) was found inactive against the used microbes. Ea.Cr, Ea.Hex, Ea.CHCl3, Ea.EtAc and Ea.Aq caused mortality of Tribolium castaneum and Ephestia cautella insects observed after 24 and 48 h of treatment. These data indicate that E. angustifolia exhibits different heavy metals and compound groups. Methanolic extract of E. angustifolia and its various fractions possess antibacterial, antifungal and insecticidal activities, which elucidate medicinal application of the plant.

Hypervalent Bromine Compounds: Smaller, More Reactive Analogues of Hypervalent Iodine Compounds

Moving up a row in the Periodic Table leads from hypervalent iodine compounds to hypervalent bromine compounds, which are now readily available (see scheme). These compounds are more reactive than the well-known heavier analogues and undergo new reactions.

Antitussive and toxicological evaluation of Vitex negundo.

Vitex negundo Linn. (Verbenaceae) is used in traditional medical system for respiratory disorders. This study was carried out to investigate its cough-relieving potential. The antitussive effect of the butanolic extract of V. negundo (Vn) on sulphur dioxide (SO2)-induced cough was examined in mice. Safety profile of Vn was carried out by observing acute neurotoxicity, median lethal dose (LD50) and behavioural signs. Vn dose-dependently (250–1000 mg kg−1) inhibited the cough provoked by SO2 gas in mice and exhibited maximum protection after 60 min of administration. At 1000 mg kg−1, Vn caused maximum cough-suppressive effects i.e. cough inhibition at 60 min was 67.4%, as compared to codeine (10 mg kg−1), dextromethorphan (10 mg kg−1) and saline having cough-inhibitory potential 75.7%, 74.7% and 0%, respectively. LD50 value of V. negundo was found to be greater than 5000 mg kg−1. In toxicity tests, no signs of neural impairment and acute behavioural toxicity were observed at antitussive doses and extract has been well tolerated at higher doses. These results indicate that V. negundo exhibits antitussive effect and it was found devoid of toxicity.

Cytotoxic and phytotoxic actions of Heliotropium strigosum

This study describes the cytotoxic and phytotoxic activities of the crude extract of Heliotropium strigosum and its resultant fractions. In brine shrimp toxicology assays, profound cytotoxicity was displayed by ethyl acetate (LD50 8.3 μg/ml) and chloroform (LD50 8.8 μg/ml) fractions, followed by relatively weak crude methanolic extract of H. strigosum (LD50 909 μg/ml) and n-hexane fraction (LD50 1000 μg/ml). In case of phytotoxicity activity against Lemna acquinoctialis, highest phytotoxic effect was showed by ethyl acetate fraction (LD50 91.0 μg/ml), while chloroform fraction, plant crude extract and n-hexane, respectively, caused 50%, 30.76 ± 1.1% and 30.7 ± 1.1% inhibitory action at maximum concentration used, that is, 1000 μg/ml. These data indicates that H. strigosum exhibits cytotoxic and phytotoxic potential, which explore its use as anticancer and herbicidal medicine. The ethyl acetate and chloroform fractions were more potent for the evaluated toxicity effects, thus recommended for isolation and identification of the active compounds.