Biomedical subjects

Kiran Iqbal

Publications and source records attributed to Kiran Iqbal.

4 recordsLinked to original sources

PubMed2005

Isolation and lipoxygenase-inhibition studies of phenolic constituents from Ehretia obtusifolia.

The phenolic compounds methyl 2-O-feruloyl-1a-O-vanillactate (1), caffeic anhydride (2), and trans 4-hydroxycyclohexyl-2-O-p-coumaroyl beta-D-glucopyranoside (3) have been isolated from the AcOEt-soluble fraction of Ehretia obtusifolia, along with methyl rosmarinate (4) and rosmarinic acid (5), which are reported for the first time from this species. Their structures were determined by means of 1D- and 2D-NMR techniques. Compounds 1-5 inhibited lipoxygenase in a concentration-dependent manner, with Ki values ranging from 0.85-57.6 microM. Compounds 1, 2, 4, and 5 showed noncompetitive inhibition, whereas 3 was found to be an uncompetitive inhibitor of lipoxygenase.

Boraginaceae↗

PubMed2004

Alpha-glucosidase inhibitory constituents from Duranta repens.

Three C-alkylated flavonoids 7-O-alpha-D-glucopyranosyl-3,5-dihydroxy-3'-(4"-acetoxyl-3"-methylbutyl)-6,4'-dimethoxyflavone (1), 7-O-alpha-D-glucopyranosyl-3,4'-dihydroxy-3'-(4"-acetoxyl-3"-methylbutyl)-5,6-dimethoxyflavone (2), 3,7,4'-trihydroxy-3'-(8"-acetoxy-7"-methyloctyl)-5,6-dimethoxyflavone (3) and a trans-clerodane type diterpenoid (-)-6beta-hydroxy-5beta,8beta,9beta,10alpha-cleroda-3,13-dien-16,15-olid-18-oic acid (4) are reported from Duranta repens along with (+)-hardwickiic acid (5) and (+)-3,13-clerodadien-16,15-olid-18-oic acid (6), isolated for the first time from this species. Their structures were established on the basis of the spectral methods, especially two dimensional (2D) NMR spectroscopy.

Enzyme Inhibitors↗

PubMed2002

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.

Conyza↗

PubMed2002

Novel sphingolipids from Conyza canadensis.

New sphingolipids, 1,3,5-trihydroxy-2-hexadecanoylamino-(6E,9E)-heptacosdiene (1). 1,3,5-trihydroxy-2-hexadecanoylamino-(6E,9E)-heptacosdiene-1-O-glucopyranoside (2). 1,3-dihydroxy-2-hexanoylamino-(4E)-heptadecene (3). have been isolated from Conyza canadensis, along with five known compounds, p-hydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 3,5-dimethoxybenzoic acid, 3beta-hydroxyolean-12-en-28-oic acid, and 3beta-erythrodiol, isolated for the first time from this species. Their structures were determined by spectroscopic methods ((1)H- and (13)C-NMR, IR and MS) and two dimensional (2D)-NMR experiments.

Conyza↗