Synthesis, characterisation and antitumour activity of some quercetin analogues.

Quercetin is one of the most abundant naturally occurring flavonoid and is associated with a wide range of biological activities, such as antioxidant, antiinflammatory and anticancer activities. However, there are multiple problems associated with the bioavailability of quercetin, thereby restricting its use. Taking this into consideration, the structure of quercetin was modified by removal of multiple hydroxyl groups and introduction of substituents such as Cl, OCH3 and N (CH3)2 on the p-position of the B-ring.

A simple HPLC method for quantitation of quercetin in herbal extracts.

A reversed-phase HPLC method with UV detection was developed for the determination of quercetin. The method produced linear response over a wide concentration range, with an average accuracy of 95% and average intra- and interday variation of 0.75 and 0.

Antioxidant and antihyperlipidemic activity of Hibiscus sabdariffa Linn. leaves and calyces extracts in rats.

Antioxidant and antihyperlipidemic activities of the extracts of leaves and calyces of Hibiscus sabdariffa were investigated by studying their in vitro inhibitory activity on lipid peroxidation and in vivo effects on cholesterol induced hyperlipidemia. Highest antioxidant activity was exhibited by ethanolic extract of calyces followed by ethanolic extract of leaves followed by aqueous extract of leaves of H. sabdariffa.

Antioxidant and Antiinflammatory Activity of Vitex negundo.

Reactive oxygen species are implicated in various inflammatory disorders. Vitex negundo is mentioned in Ayurveda as useful in treating arthritic disorders. The present work was undertaken to evaluate the antioxidant potential and anti-inflammatory activity of the plant.