Zahramycins A-B, Two New Steroids from the Coral Sarcophyton trocheliophorum

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 ( 1 H, 13 C, 1 H-1 H 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.

Marine natural products

“…825 Three studies of Red Sea (Hurghada) cnidarians afforded steroidshurgadacin 1026 was isolated from Sinularia polydactyla, 826 gorgostane 1027 (¼ 11-acetyl-sarcoaldosterol A 827 ) from Heteroxenia ghardaqensis 828 and zahramycins A 1028 and B 1029 from Sarcophyton trocheliophorum. 829 Zahramycin B exhibited modest antibacterial activity.…”

The Soft Coral Sarcophyton trocheliophorum: A Warehouse of Terpenoids with Structural and Pharmacological Diversity

“…As revealed in the literature [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ], most of the chemically investigated S. trocheliophorum specimens were collected off the islands in the South China Sea and Indian Ocean, and off the coasts of Saudi Arabia, Egypt, and Australia. These collection sites can be divided into three sea waters: the Pacific Ocean, the Indian Ocean, and the Red Sea.…”

“…Since the first chemical investigation reported in 1976 [ 3 ], continuous chemical studies on this soft coral have led to the discovery of numerous secondary metabolites with diverse structural features, implying that S. trocheliophorum has become one of the hotspots of marine natural product research. Structurally, these chemical compositions comprise terpenes [ 4 , 5 , 6 , 7 ], steroids [ 8 , 9 , 10 , 11 ], prostaglandins [ 12 ], γ-butenolides [ 12 , 13 ], phenolics [ 14 ], etc. Among these metabolites, terpenoids are the dominative constituents.…”

Chemical Diversity in Species Belonging to Soft Coral Genus Sacrophyton and Its Impact on Biological Activity: A Review

“…Chemical investigation of the polar fraction of S. trocheliophorum, yielded two poly-hydroxy steroids, identified through extensive spectral analysis as zahramycins A and B 404 and 405. Zahramycin A 404 was characterized by the existence of oxirane ring at carbon-5 and carbon-6, while zahramycin B 405 possessed a keto-hydroxy sterol structure [117].…”