Naheed Riaz

Mild and efficient synthesis of new tetraketones as lipoxygenase inhibitors and antioxidants

A mild and efficient route to tetraketones (2–22) has been developed by way of tetraethyl ammonium bromide (Et4N+Br− ) mediated condensation of dimedone (5,5-dimethylcyclohexane-1,3-dione, 1) with a variety of aldehydes. All these compounds showed significant lipoxygenase inhibitory activity and moderate to strong antioxidant potential. Compounds 19 (IC50 = 7.8 μM), 22 (IC50 = 12.5 μM), 3 (IC50 = 16.3 μM), 11 (IC50 = 17.5 μM) and 8 (IC50 = 21.3 μM) showed significant inhibitory potential against lipoxygenase (baicalein, IC50 = 22.4 μM). On the other hand compound 19 (IC50 = 33.6 μM) also showed strong antioxidant activity compared to the standard (IC50 = 44.7 μM). This study is likely to lead to the discovery of therapeutically efficient agents against very important disorders including inflammation, asthma, cancer and autoimmune diseases.

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.

Lipoxygenase inhibitory constituents from Indigofera oblongifolia.

Indigin, alkylated xanthene (1) and indigoferic acid (2) have been isolated from the chloroform soluble fraction ofIndigofera oblongifolia, along with β-sitosterol (3) and 3-hydroxybenzoic acid (4), which are reported for the first time from this species. Their structures were determined through spectroscopic techniques. Both the new compounds1 and2 showed significant activity against enzyme lipoxygenase, while2 further showed moderate inhibition against BChE.

New butyrylcholinesterase inhibitory triterpenes from Salvia santolinifolia.

Slavins A (1) and B (2), the new amyrin type triterpenes, have been isolated from the chloroform soluble fraction ofSalvia santolinifolia and assigned structures on the basis of spectral studies including 2D NMR. Both the compounds displayed inhibitory potential against the enzyme butyrylcholinesterase.

Chymotrypsin inhibitory constituents from Haloxylon recurvum

Haloxylase, the triglyceride (1), unsaturated fatty acid (2), and saturated fatty acid methyl ester (3) have been isolated from the chloroform-soluble fraction of Haloxylon recurvum. Their structures have been elucidated through spectroscopic studies and chemical transformation. All these compounds showed significant inhibitory activity against the enzyme chymotrypsin in a concentration dependent fashion.

Alysinol - A New Triterpene from Alysicarpus Monolifer

A new triterpene named as alysinol 3 f , 22 g -dihydroxyolean-12-ene 1 along with known compounds usnic acid, methyl 2,4-dihydroxy-3,6-dimethyl benzoate, 3-hydroxy benzoic acid, stigmasterol, poriferasterol and ursolic acid have been isolated from Alysicarpus monolifer . The structure of 1 has been established through spectroscopic techniques.