Sadia Khan

Synthesis and enzyme inhibitory activities of some new pyrazole-based heterocyclic compounds

Three tridentate N,N-bis(3,5-dimethylpyrazol-1-ylmethyl)-1-hydroxy-2-aminoethane (2), N,N-bis(3,5-dimethylpyrazol-1-ylmethyl)-cyclohexylamine (3) and 2-[bis(1,5-dimethyl-1H-pyrazol-3-ylmethyl)amino]ethan-1-ol (4) are synthesized and spectroscopically characterized together with 1-hydroxymethyl-3,5-dimethylpyrazole (1). These have been tested in inhibitory activities against various hyperactive enzymes like urease, β-glucuronidase, phosphodiesterase, α-chymotrypsin, acetylcholinesterase and butyrylcholinesterase. Compounds 1, 2 and 3 were found to be selective inhibitors of urease. Compound 4 was found to be selective inhibitor of butyrylcholinesterase. The nature of the junction between pyrazoles cycles determined the activities of these tripods. While the tripods are inactive towards urease or glucuronidase, they turn to be selective towards butyrylcholinesterase.

Synthesis and Antibacterial and Antifungal Activity of 5-Substituted Imidazolones

A variety of imidazolones 1-34 derivatives were synthesized and tested for their antibacterial effects against Escherichia coli, Bacillus subtilis, Shigella flexnari, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhi. Compound 18 found to be moderately active against S. flexnari, however, compounds 8, 11, 15, 21, 22, 25 showed to be moderate and compounds 31 and 34 exhibited good activities against P. aeruginosa. Compounds 7, 9, 12-14, 24-26, and 29 demonstrated good to excellent activity against S. typhi, while remaining compound did not show significant antibacte- rial activities. Compounds 7, 9, 12, 13, 14, 25, 26, 29 showed good activities against S. typhi. The antifungal activities of imidazolones were also determined against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, Candida glabrata and found that compounds showed varying degree of percentage inhibition.

Alliumonoate: a new cyclopentane derivative from Allium victorialis.

Alliumonoate (1), a new cyclopentane derivative, has been isolated from the chloroform-soluble fraction of the ethanolic extract of Allium victorialis, along with β-amyrin acetate (2), β-sitosterol acetate (3), 22-cyclohexyl-1-docosanol (4), β-amyrin (5), β-sitosterol (6), and β-sitosterol 3-O-β-d-glucopyranoside (7), reported for the first time from this species. Their structures were elucidated on the basis of spectral data including mass spectra and 2D NMR experiments.

New antimicrobial flavonoids and chalcone from Colutea armata

Colucins A (1) and B (2), new flavonoids and colucone (3), the new chalcone derivative, have been isolated from the CHCl3-soluble fraction of the whole plant of Colutea armata along with luteolin (4), luteolin 7-O-β-D-glucoside (5), isoliquiritigenin (6), trans-caffeic acid (7) and stigmasterol (8) reported for the first time from this species. Their structures were elucidated by spectroscopic techniques including MS and 2D-NMR spectroscopy. Compounds 1 and 2 showed significant antimicrobial activity against two Gram positive and three Gram negative bacterial strains while 3 was moderately active.

Cashmins A and B, Potent Antioxidant Coumarins from Sorbus cashmiriana

Cashmins A (1) and B (2), two new coumarins, have been isolated from the chloroform-soluble subfraction of the methanolic extract of Sorbus cashmiriana Hedl. Both compounds showed potent antioxidant activity in different antioxidant assays.

Brahin, a New Lipoxygenase Inhibiting Triterpene from Spiraea brahuica

Brahin (1), a new ursene-type triterpene, has been isolated from the CHCl3-soluble fraction of Spiraea brahuica together with β-sitosterol (2), 3-(3,4-dimethoxyphenyl)-2-propenal (3), and cinnamic acid (4), which are reported for the first time from this species. The structures of these compounds were elucidated by 1D and 2D NMR spectroscopic techniques. Brahin showed moderate inhibitory activity against the enzyme lipoxygenase.

Colutin, new antifungal isoflavan from Colutea armata

A new isoflavan, colutin (1), has been isolated from the EtOAc soluble fraction of the MeOH extract of Colutea armata, along with three known compounds, sativan (2), isovestitol (3), and cinnamic acid (4), isolated for the first time from this species. Their structures were elucidated by spectroscopic techniques including two-dimensional NMR. Colutin (1) showed significant antifungal activity.

A New Steroidal Alkaloid from Allium victorialis

Allumine C (1), a new steroidal alkaloid, has been isolated from the CHCl3-soluble fraction of the whole plant of Allium victorialis L. Its structure was elucidated by chemical and spectral studies.