title: Mirabolides A and B; New Cytotoxic Glycerides from the Red Sea Sponge Theonella mirabilis.
abstract: As a part of our continuing work to find out bioactive lead molecules from marine invertebrates, the CHCl₃ fraction of the organic extract of the Red Sea sponge Theonella mirabilis showed cytotoxic activity in our primary screen. Bioassay-guided purification of the active fractions of the sponge's extract resulted in the isolation of two new glycerides, mirabolides A and B (1 and 2), together with the reported 4-methylene sterols, conicasterol (3) and swinhosterol B (4). The structures of the compounds were assigned by interpretation of their 1D (¹H, (13)C), 2D (COSY, HSQC, HMBC, ROESY) NMR spectral data and high-resolution mass determinations. Compounds 1-4 displayed marked cytotoxic activity against human breast adenocarcinoma cell line (MCF-7) with IC50 values of 16.4, 5.18, 6.23 and 3.0 μg/mL, respectively, compared to 5.4 μg/mL observed by doxorubicin as reference drug.
authors.affiliation: Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia. dabouhussein@kau.edu.sa.|Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Kasr El-Aini, Cairo 11562, Egypt. dabouhussein@kau.edu.sa.
authors.forename: Dina R
authors.initials: DR
authors.lastname: Abou-Hussein
authors.affiliation: Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia. dyoussef@kau.edu.sa.
authors.forename: Diaa T A
authors.initials: DT
authors.lastname: Youssef
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002784:Cholesterol / Q000031:analogs & derivatives / Q000302:isolation & purification / Q000494:pharmacology; D004317:Doxorubicin / Q000494:pharmacology; D005260:Female; D005989:Glycerides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D019156:Indian Ocean; D020128:Inhibitory Concentration 50; D061986:MCF-7 Cells; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D047232:Theonella / Q000737:chemistry*
chemical_list: D000903:Antibiotics, Antineoplastic; D005989:Glycerides; C098158:conicasterol; C000620748:mirabolide A; C000620749:mirabolide B; D004317:Doxorubicin; D002784:Cholesterol
keywords: 4-methylene sterols; Mirabolides A and B; Red Sea sponge Theonella mirabilis; breast cancer cell line; cytotoxic activity; glycerides