title: Callyptide A, a new cytotoxic peptide from the Red Sea marine sponge Callyspongia species.
abstract: In the course of our continuing efforts to allocate bioactive secondary metabolites from Red Sea marine invertebrates, we have investigated the sponge Callyspongia species. The cytotoxic dichloromethane fraction of the methanolic extract of the sponge afforded a new cytotoxic peptide named callyptide A (1). Its structure was determined by extensive 1D and 2D NMR (COSY, HSQC and HMBC) studies and high-resolution mass spectral determination. The configuration of the amino acids was determined by Marfey's analysis. Callyptide A was found to exhibit growth inhibitory activity when tested against different cancer cell lines.
authors.affiliation: a Natural Products Unit, King Fahd Medical Research Center , King Abdulaziz University , Jeddah , Saudi Arabia.|b Suez Canal University Hospital , Suez Canal University , Ismailia , Egypt.
authors.forename: Lamiaa A
authors.initials: LA
authors.lastname: Shaala
authors.affiliation: c Department of Natural Products and Alternative Medicine, Faculty of Pharmacy , King Abdulaziz Universrabiaity , Jeddah , Saudi Arabia.
authors.forename: Diaa T A
authors.initials: DTA
authors.lastname: Youssef
authors.affiliation: d Department of Pharmacognosy and Medicinal Chemistry, College of Pharmacy , Taibah University , Al Madinah Al Munawwarah , Saudi Arabia.|e Faculty of Pharmacy, Department of Pharmacognosy , Assiut University , Assiut , Egypt.
authors.forename: Sabrin R M
authors.initials: SRM
authors.lastname: Ibrahim
authors.affiliation: c Department of Natural Products and Alternative Medicine, Faculty of Pharmacy , King Abdulaziz Universrabiaity , Jeddah , Saudi Arabia.|f Faculty of Pharmacy, Department of Pharmacognosy, Assiut Branch , Al-Azhar University , Assiut , Egypt.
authors.forename: Gamal A
authors.initials: GA
authors.lastname: Mohamed
keywords:  species; Red Sea sponge; callyptide A; cancer cell lines; cytotoxic activity