Callyaerin g, a new cytotoxic cyclic peptide from the marine sponge callyspongia aerizusa

From the ethyl acetate fraction of the Indonesian sponge Callyspongia aerizusa extract, a new cyclic peptide named callyaerin G was isolated. Its structure was elucidated by extensive 1D and 2D NMR (1H NMR, TOCSY and ROESY) studies and mass spectrometric data (ESI- and FAB-MS). The stereochemistry was determined by Marfey's analysis. Callyaerin G was found to exhibit cytotoxic activity when tested against different cancer cell lines

Proceraside A, a new cardiac glycoside from the root barks of <i>Calotropis procera</i> with <i>in vitro</i> anticancer effects

<div><p>We have studied the ethyl acetate fraction of the methanolic extract of the root barks of <i>Calotropis procera</i> (Asclepiadaceae) from Egypt. Bioassay-directed fractionation and final purification of the extract resulted in the identification of a new cardenolide glycoside named proceraside A (<b>1</b>) together with two known compounds, frugoside (<b>2</b>) and calotropin (<b>3</b>). Their structures were elucidated by extensive NMR studies and mass spectrometric data. The <i>in vitro</i> cytotoxicity of the isolated compounds was evaluated against A549 non-small cell lung cancer, U373 glioblastoma and PC-3 prostate cancer cell lines. They showed potent activity against the tested cancer cell lines with IC₅₀ ranging from 0.005 to 0.3 μg/mL. Cisplatin was used as positive control.</p></div