Irshad Ali

Antifungal steroidal lactones from Withania coagulance

Two new withanolides, 14,15 beta-epoxywithanolide I [(20S,22R) 17 beta, 20 beta-dihydroxy-14 beta,15 beta-epoxy-1-oxo-witha-3,5,24-trienolide] and 17 beta-hydroxywithanolide K (20S,22R) 14 alpha,17 beta,20 beta-trihydroxy-1-oxo-witha-2,5,24-trienolide] have been isolated from the whole plant of Withania coagulance and their structures were elucidated by spectroscopic techniques. The latter compound was found to be active against a number of potentially pathogenic fungi.

Antibacterial, antifungal, antispasmodic and Ca++ antagonist effects of Caesalpinia bonducella

Caesalpinia bonducella F. (Leguminosae) has been used as a folk medicine for a variety of ailments. The crude extract of C. bonducella and its fractions were studied for antibacterial, antifungal, antispasmodic and Ca++ antagonistic properties. The strongest antibacterial effect was displayed by the n-butanol (72%) and ethyl acetate (80%) fractions, followed by the crude extract (46% and 42%), against Escherichia coli and Bacillus subtilis, respectively. The plant extract and its fractions showed mild to excellent activity in antifungal bioassays, with maximum antifungal activity against Candida glaberata (80%) and Aspergillus flavus (70%) by the n-butanol and chloroform fractions, followed by the crude extract (70% and 65%). Caesalpinia bonducella extract caused concentration-dependent inhibition of spontaneous and high K+ (80 mM)-induced contractions of isolated rabbit jejunum preparations, similar to that caused by Verapamil. These results indicate that C. bonducella exhibits antibacterial, antifungal, spasmolytic and Ca++ channel blocking actions.

Phytochemical studies and antibacterial activity of Centaurium pulchellum Druce

Two isocoumarin derivatives, one new, erythricin (1) and a known erythrocentaurin (2) were isolated from the whole plant of Centaurium pulchellum Druce. The 13C-NMR data of compound 2 are described. The structures of compounds 1, 2 were elucidated on the basis of spectral analysis including 2D-NMR experiments. Antibacterial and brine shrimp lethality assays are also described on the fractions of the plant extract.

New natural urease inhibitors from Ranunculus repens

Phytochemical investigations on the chloroform and ethyl acetate soluble fractions of the roots of Ranunculus repens led to the isolation of methyl 3,4,5-trihydroxybenzoate 1, R(+)- 4-methoxydalbergione 2 and R(+)-dalbergiophenol 3. The structures of these compounds were established through spectral studies including 1D and 2D NMR experiments and by comparison with literature data. These compounds showed potent inhibitory activity against urease.

Preparation and Evaluation of Controlled Release Tablets Containing Mefenamic Acid

In the present study, Mefenamic acid 200 mg controlled release matrices were prepared by direct compression and in vitro drug dissolution studies were performed to find out the drug release rate and patterns. Methocel was used as rate controlling polymer. Also the effect of several co-excipients was investigated on the drug release rates during in vitro dissolution studies. Polymer Methocel was used as a rate controlling polymer and was formulated with the drug at 4 different D: P ratios. Phosphate buffer pH 7.2 was used as dissolution medium using PharmaTest dissolution apparatus. Several kinetic models were applied to the dissolution profiles to determine the drug release kinetics. Dissolution equivalency evaluation was performed using f2 similarity factor.

Xanthine oxidase inhibiting compounds from Ranunculus repens

The genus Ranunculus belongs to the family Ranunculaceae, which comprises 50 genera and 2000 species. In Pakistan, it is represented by 22 genera and 114 species. The phytochemical studies on various species of genus Ranunculus have reported that they contain anemone [1], carotene [2], flavone-glycosides [3], and ranuncosides [4]. The saline extracts of some species have been reported to possess anti-bacterial, anti-fungal, and anti-malarial activities [5–7]. Ranunculus repens L. is widely distributed in the northern areas of Pakistan and is used for medicinal purposes [8]. Several genera in this family possess ir ritant properties due to the presence of protoanemonin [9, 10]. The protoanemonin also inhibits mitosis in plant cells [11]. No work has been reported so far on this species. The diverse medicinal uses attributed to this species prompted us to carry out phytochemical and biological studies on this plant. Biological screening of the methanolic extract revealed significant inhibit ory activity against the enzyme xanthine oxidase [12]. On fractionation, the major inhibitory activity against this enzyme was detected in the chloroform soluble fraction. The chloroform soluble fraction resulted in the isolation and structure elucidatio n of R(+)-dalbergiphenol ( 1), R(+)-4-methoxydalbergione ( 2), and methyl-3,4,5-trihydroxybenzoate ( 3). All of them have been reported for the first time from this plant.

Methyl 5-chloro-2-hydr­oxy-3-(4-methoxy­phen­yl)-4,6-dimethyl­benzoate

In the title compound, C17H17ClO4, the dihedral angle between the mean planes of the two benzene rings is 65.92 (5)°. The methyl ester group lies within the ring plane [deviations of O atoms from the plane = −0.051 (2) and 0.151 (2) Å] due to an intramolecular O—H⋯O hydrogen bond. In the crystal, molecules are held together by rather weak non-classical intermolecular C—H⋯O hydrogen bonds, resulting in dimeric units about inversion centers, forming eight- and ten-membered ring systems as R 2 2(8) and R 2 2(10) motifs.