Reactions of Podophyllotoxin with DDQ

Introduction 2, 3-Dichloro-5, 6-dicyanobenzoquinone (DDQ) can react with lignans of the mono- arylidene-butyrolactone1, aryltetralin2, dibenzylbutane3 and aryltetralin-butyrolactone4,5 series. We have studied the reactions of this reagent with podophyllotoxin 1, which is a well-known natural product on account of its long history of use in folk medicine and the biological activity of its many derivatives6. In particular, derivatives of 4-demethyl epipodophyllotoxin are used in cancer chemo…     

Inhibition of cPLA2 and sPLA2 activities in primary cultures of rat cortical neurons by Centella asiatica water extract

Leaf extract of Centella asiatica has been used as an alternative medicine for memory improvement in the Indian Ayurvedic system of medicine for a long time. Although several studies have revealed its effect in ameliorating the cognitive impairment in rat models of Alzheimer's disease, the molecular mechanism of C. asiatica on neuroprotection still remains unexplained. In this study, we investigated the effects of C. asiatica water extract on activity of subtypes of phospholipase A2 (PLA2) in primary cultures of rat cortical neurons and quantified by HPLC a possible molecule responsible for the activity. The cPLA2 and sPLA2 activities were inhibited in vitro by asiaticoside present in the water extract of C. asiatica. This extract may be a candidate for the treatment of neurodegenerative processes because of its pharmacological activity in the brain and its low toxicity, as attested by its long popular use as a natural product.