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Z. Naturforsch. 2013,
68b, 939 – 945
doi:10.5560/ZNB.2013-3131
Zahramycins A-B, Two New Steroids from the Coral Sarcophyton trocheliophorum
1 Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany
2 Chemistry of Natural Compounds Department, Division of Pharmaceutical Industries, National Research Centre, El-Behoos st. 33, Dokki-Cairo 12622, Egypt
3 Red Sea Marine Parks, P. O. Box 363, Hurghada, Red Sea, Egypt
† Authors contributed equally to the work
Reprint requests to Prof. Dr. M. Shaaban. Tel: +202-2701728/int-2609. Fax: +202-33370931. E-mail:
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Received May 7, 2013 / published online July 25, 2013
Two new poly-hydroxy steroids, zahramycins A (1) and B (2), have been isolated from the polar fraction of the extract of the coral Sarcophyton trocheliophorum. Compound 1 was confirmed to bear an oxirane ring at C-5 and C-6, while 2 has a keto-hydroxy sterol structure. The known DNA primary metabolites uracil, thymine, adenine, uridine, 2′-deoxyuridine, and thymidine were also isolated and identified. Structures of the new sterols 1 and 2 were confirmed by NMR (1H, 13C, 1H-1H COSY, HMQC, HMBC, and NOESY) spectroscopy, mass spectrometry (EI, ESI, and HRMS), and by comparison with related structures. The antimicrobial and cytotoxic activities of compounds 1 and 2 along with that of the coral extract were also determined. Zahramycin B (2) showed high (15 mm) and moderate (12 mm) antibacterial activity against Staphylococcus aureus and Bacillus subtilis, and fungus Pythium ultimum (12 mm), while zahramycin A (1) and the crude extract of Sarcophyton trocheliophorum were inactive. Both steroids and the crude extract of Sarcophyton trocheliophorum showed no cytotoxicity.
Key words: Zahramycins, Polyoxygenated Sterols, Sarcophyton trocheliophorum, Biological Activity