Zahramycins A-B, two new steroids from the coral Sarcophyton trocheliophorum

Mohamed Shaaban, Mohamed A. Ghani, Khaled A. Shaaban

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

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 (H, C, 1H-1hcosy, 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 (12mm), 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.

Original languageEnglish
Pages (from-to)939-945
Number of pages7
JournalZeitschrift fur Naturforschung - Section B Journal of Chemical Sciences
Volume68
Issue number8
DOIs
StatePublished - Aug 2013

Bibliographical note

Funding Information:
The authors are deeply thankful to Prof. H. Laatsch, Institute of Organic and Biomolecular Chemistry, University of Göttingen, for his support and laboratory facilities. We thank Dr. H. Frauendorf and Mr. R. Machinek for MS and NMR measurements. The authors would like to acknowledge Ms. F. Lissy for biological tests and Mr. A. Kohl for technical assistance. M. Shaaban thanks the German Academic Exchange Service (DAAD) for a short-term grant.

Keywords

  • Biological activity
  • Polyoxygenated sterols
  • Sarcophyton trocheliophorum
  • Zahramycins

ASJC Scopus subject areas

  • General Chemistry

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