Itrat Anis

Urease inhibitors from Hypericum oblongifolium WALL.

The bioassay-guided fractionation of H. oblongifolium has led to the isolation of potent urease inhibitors 1–3. The structures were elucidated by NMR and mass spectroscopic techniques. Compound 2 showed a potent enzyme inhibition activity (IC50 20.96 ± 0.93), which is comparatively higher than that for the standard thiourea (IC50 21.01 ± 0.51 μM). Compounds 1 and 3 also showed a significant activity, with IC50 37.95 ± 1.93 and 138.43 ± 1.23 μM, respectively. The sub crude fractions (F1, F2, F3, and F4) were tested in vitro for their urease inhibition activity. Fractions F2 and F4 showed significant activity with IC50 140.37 ± 1.93 and 167.43 ± 3.03 μM, respectively.

Sphingolipids from Conyza canadensis.

Sphingolipid 1 and its corresponding beta-D-glucopyranoside derivative 2 have been isolated from the ethylacetate fraction of Conyza canadensis along with beta-sitosterol 3, stigmasterol 4, beta-sitosterol 3-O-beta-D-glucoside 5 and harmine 6, reported for the first time from this species. The structures of 1 and 2 were elucidated through spectroscopy including two-dimensional NMR.

Thrombin inhibitory constituents from Duranta repens

The C-alkylated flavonoids 3,7,4′-trihydroxy-3′-(4-hydroxy-3-methylbutyl)-5,6-dimethoxyflavone (1), 3,7-dihydroxy-3′-(4-hydroxy-3-methylbutyl)-5,6,4′-trimethoxyflavone (2) and the trans-clerodane diterpenoids 6β-hydroxy-15,16-epoxy-5β,8β,9β,10α-cleroda-3,13(16),14-trien-18-oic acid (3) and 2β-hydroxy-15,16-epoxy-5β,8β,9β,10α-cleroda-3,13(16),14-trien-18-oic acid (4) were isolated from Duranta repens. Their structures and the relative configuration of 3 and 4 were determined by spectroscopic methods (1H- and 13C-NMR, IR, and MS) and 2D-NMR experiments. The known flavonoid 5 is also reported for the first time from this species. The compounds 1, 3, and 5 showed significant enzyme-inhibitory activity against thrombin.

Isatinones A and B, New Antifungal Oxindole Alkaloids from Isatis costata

Two new oxindole alkaloids isatinone A (1) and B (2) have been isolated from Isatis costata, along with the known trisindoline. Their structures have been assigned on the basis of spectroscopic techniques and chemical studies. Both new compounds showed significant antifungal activity.

Emodinol, ß-Glucuronidase Inhibiting Triterpene from Paeonia Emodi

Emodinol, a new oleane type triterpene, has been isolated from the chloroform soluble fraction of Paeonia emodi. The structure 1β, 3β, 23-trihydroxyolean-12-en-28-oic acid 1 has been assigned on the basis of spectral studies including 2D NMR. It showed significant β-glucuronidase inhibitory activity. In addition benzoic acid and 3-hydroxybenzoic acid have also been reported for the first time from this species.

Biologically Active C-Alkylated Flavonoids from Dodonaea viscosa

A new C-alkylated flavonoid (5,7-dihydroxy-3′-(4″-acetoxy-3″-methylbutyl)-3,6,4′-trimethoxyflavone (1), along with two known C-alkylated flavonoids (5,7-dihydroxy-3′-(3-hydroxymethylbutyl)-3,6,4′-trimethoxyflavone (2), 5,7,4′-trihydroxy-3′-(3-hyroxymethylbutyl)-3,6-dimethoxyflavone (3) and two new source C-alkylated flavonoids (5,7-dihydroxy-3′-(2-hydroxy-3-methyl-3-butenyl)-3,6,4′-trimethoxyflavone (4), 5,7,4′-trihydroxy-3,6-dimethoxy-3′-isoprenyl-flavone (5) were isolated from the aerial parts of Dodonaea viscosa. The structures of all compounds were established on the basis of 1D and 2D NMR spectroscopy and mass spectrometry. The isolated compounds were evaluated for their inhibitory effect on urease and α-chymotrypsin enzyme. All the compounds (1–5) exhibited mild inhibition against urease but remained recessive in case of α-chymotrypsin.

Green synthesis and molecular recognition ability of patuletin coated gold nanoparticles.

Patuletin isolated from Tagetespatula was used as a capping and reducing agent to synthesize in one pot gold nanoparticles capped with patuletin. Conjugation of gold with patuletin was confirmed by FT-IR and UV-visible spectroscopy and amount of patuletin conjugated to gold nanoparticles was found to be 63.2% by weight. Particle sizes were measured by atomic force microscopy (AFM) and were found to have a mean diameter of about 45 nm. Patuletin-coated gold nanoparticles were found to be highly fluorescent. To examine their potential as chemical sensors, they were contacted with fourteen different drugs. Of these drugs, only one, piroxicam, was found to quench luminescence. Quenching obeyed Beers law in a concentration range of 20-260 µM. Important for molecular recognition applications, fluorescence quenching by piroxicam was not affected by pH variation, elevated temperatures, addition of other drugs and addition of blood plasma to the colloidal suspensions.

Methylenebissantin: A rare methylene-bridged bisflavonoid from Dodonaea viscosa which inhibits Plasmodium falciparum enoyl-ACP reductase

A new methylene-bridged bisflavonoid, methylenebissantin (1), and nine known compounds, including flavonoids (2-5), diterpenoids (6 and 7), and phenol derivatives (8-10) were isolated from the aerial parts of Dodonaea viscosa Jacq. The structure elucidation was based on spectroscopic data analyses. The isolated compounds were evaluated for the inhibition of Plasmodium falciparum enoyl-ACP reductase (PfENR). Methylenebissantin (1) exhibited a moderate inhibition (IC(50) 91.13 μM) against PfENR.

In vitro antifungal and antibacterial activities of extracts of Galium tricornutum subsp. longipedunculatum

The aim of this study was to evaluate the antimicrobial activity of crude ethanolic extracts and fractions of the ariel parts and the fruits of Galium tricornutum subsp. longipedunculatum, traditionally used in northern areas of Pakistan for treating microbial infections of skin. Extracts and their fractions were tested against six bacteria and six fungal strains using the hole diffusion method and macrodilution method. All extracts and fractions possessed significant antimicrobial effect. Four fungal strains, Candida albicans, Trichophyton longifusus, Fusarium.solani and Candida glabrata, showed interesting susceptibility profiles when evaluated using the extracts and fractions with MICs ranging from 0.18 to 200 mg/mL. In case of bacterial strains, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi were significantly susceptible to the extracts and fractions with MICs ranging from 0.12 to 200 mg/mL. Comparative results were carried out using imepenem, miconazole and amphotericin B as standard antibiotics.

Govanoside A, a new steroidal saponin from rhizomes of Trillium govanianum.

A new spirostane steroidal saponin, govanoside A (1) along with three known compounds borassoside E (2) pennogenin (3) and diosgenin (4) were isolated from rhizomes of Trillium govanianum. Their structures were elucidated through 1D, 2D-NMR spectroscopic data analysis and acid hydrolysis. Compound (2) in genus Trillium and all compounds (1-4) in T. govanianum are reported herein for the first time. Furthermore, compounds 1 &2 exhibited good to moderate activities against Aspergillus niger ATCC 16888, Aspergillus flavus ATCC 9643, Candida albicans ATCC 18804, and Candida glabrata ATCC 90030. This is a significant finding keeping in view the limited antifungal drugs for aspergillosis and candidiasis.