title: Cytotoxic Compounds from the Saudi Red Sea Sponge Xestospongia testudinaria.
abstract: Bioassay-guided fractionation of the organic extract of the Red Sea sponge Xestospongia testudinaria led to the isolation of 13 compounds including two new sterol esters, xestosterol palmitate (2) and xestosterol ester of l6'-bromo-(7'E,11'E,l5'E)-hexadeca-7',11',l5'-triene-5',13'-diynoic acid (4), together with eleven known compounds: xestosterol (1), xestosterol ester of 18'-bromooctadeca-7'E,9'E-diene-7',15'-diynoic acid (3), and the brominated acetylenic fatty acid derivatives, (5E,11E,15E,19E)-20-bromoeicosa-5,11,15,19-tetraene-9,17-diynoic acid (5), 18,18-dibromo-(9E)-octadeca-9,17-diene-5,7-diynoic acid (6), 18-bromooctadeca-(9E,17E)-diene-7,15-diynoic acid (7), 18-bromooctadeca-(9E,13E,17E)-triene-7,15-diynoic acid (8), l6-bromo (7E,11E,l5E)hexadeca-7,11,l5-triene-5,13-diynoic acid (9), 2-methylmaleimide-5-oxime (10), maleimide-5-oxime (11), tetillapyrone (12), and nortetillapyrone (13). The chemical structures of the isolated compounds were accomplished using one- and two-dimensional NMR, infrared and high-resolution electron impact mass spectroscopy (1D, 2D NMR, IR and HREIMS), and by comparison with the data of the known compounds. The total alcoholic and n-hexane extracts showed remarkable cytotoxic activity against human cervical cancer (HeLa), human hepatocellular carcinoma (HepG-2), and human medulloblastoma (Daoy) cancer cell lines. Interestingly, the dibrominated C18-acetylenic fatty acid (6) exhibited the most potent growth inhibitory activity against these cancer cell lines followed by Compounds 7 and 9. Apparently, the dibromination of the terminal olefinic moiety has an enhanced effect on the cytotoxic activity.
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia. aelgamal00@yahoo.com.|Department of Pharmacognosy, Faculty of Pharmacy, Mansoura University, El-Mansoura 35516, Egypt. aelgamal00@yahoo.com.
authors.forename: Ali A
authors.initials: AA
authors.lastname: El-Gamal
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia. aelgamel@ksu.edu.sa.
authors.forename: Shaza M
authors.initials: SM
authors.lastname: Al-Massarani
authors.affiliation: Natural Products Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia. lshalla@kau.edu.sa.|Suez Canal University Hospital, Suez Canal University, Ismailia 41522, Egypt. lshalla@kau.edu.sa.
authors.forename: Lamiaa A
authors.initials: LA
authors.lastname: Shaala
authors.affiliation: Department of Clinical Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia. amalahdal@kau.edu.sa.
authors.forename: Abdulrahman M
authors.initials: AM
authors.lastname: Alahdald
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia. salmassarani@ksu.edu.sa.
authors.forename: Mansour S
authors.initials: MS
authors.lastname: Al-Said
authors.affiliation: Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia. aeashour@yahoo.com.
authors.forename: Abdelkader E
authors.initials: AE
authors.lastname: Ashour
authors.affiliation: Vitiligo Research Chair, College of Medicine, King Saud University, Riyadh 11451, Saudi Arabia. aknirankari@gmail.com.
authors.forename: Ashok
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, Sattam Bin Abdulaziz University, Al-kharj 11942, Saudi Arabia. mpharm101@hotmail.com.
authors.forename: Maged S
authors.initials: MS
authors.lastname: Abdel-Kader
authors.affiliation: Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia. msalsaid@ksu.edu.sa.|Department of Pharmacognosy, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt. msalsaid@ksu.edu.sa.
authors.forename: Wael M
authors.initials: WM
authors.lastname: Abdel-Mageed
authors.affiliation: Department of Natural Products, 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; D001688:Biological Products / Q000009:adverse effects* / Q000737:chemistry; D045744:Cell Line, Tumor; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D019156:Indian Ocean; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D011161:Porifera / Q000737:chemistry*; D011753:Pyrones / Q000009:adverse effects / Q000737:chemistry; D012529:Saudi Arabia; D013256:Steroids / Q000009:adverse effects / Q000737:chemistry; D047131:Xestospongia / Q000737:chemistry*
chemical_list: D001688:Biological Products; D011753:Pyrones; D013256:Steroids; C436664:nortetillapyrone; C436663:tetillapyrone
keywords: Red Sea sponge; Xestospongia testudinaria; brominated acetylenic fatty acids; cancer cell lines; cytotoxic activity; xestosterol fatty acids esters