Bioactive Steroids from the Red Sea Soft Coral Sinularia polydactyla

Abstract

Six new (1, 2, 6, 8, 13, and 20) and twenty previously isolated (3–5, 7, 9–12, 14–19, and 21–26) steroids featuring thirteen different carbocycle motifs were isolated from the organic extract of the soft coral Sinularia polydactyla collected from the Hurghada reef in the Red Sea. The structures and the relative configurations of the isolated natural products have been determined based on extensive analysis of their NMR and MS data. The cytotoxic, anti-inflammatory, anti-angiogenic, and neuroprotective activity of compounds 3–7, 9–12, 14–20, and 22–26, as well as their effect on androgen receptor-regulated transcription was evaluated in vitro in human tumor and non-cancerous cells. Steroids 22 and 23 showed significant cytotoxicity in the low micromolar range against the HeLa and MCF7 cancer cell lines, while migration of endothelial cells was inhibited by compounds 11, 12, 22, and 23 at 20 µM. The results of the androgen receptor (AR) reporter assay showed that compound 11 exhibited the strongest inhibition of AR at 10 µM, while it is noteworthy that steroids 10, 16, and 20 displayed increased inhibition of AR with decreasing concentrations. Additionally, compounds 11 and 23 showed neuroprotective activity on neuron-like SH-SY5Y cells.

Chemical Diversity and Biological Activity of Secondary Metabolites from Soft Coral Genus Sinularia since 2013

“…Compounds 218 and 219 displayed the rare 8,9-seco-cholestane steroidal nucleus. Compound 223 displayed increased inhibition of androgen receptors with decreasing concentrations [6].…”

“…Six new steroids (218-223) were isolated from the organic extract of the soft coral S. polydactyla collected from the Hurghada reef in the Red Sea [6]. Compounds 218 and 219 displayed the rare 8,9-seco-cholestane steroidal nucleus.…”

“…As reported, Sinularia is well-known to produce a wealth of diverse and com plex secondary metabolites, such as sesquiterpenes (10%), diterpenes (46%), norsesqui erpenes (2%), norditerpenes (9%), steroids/steroidal glycosides (22%), and other type (11%) (Figure 1) [1][2][3]. These metabolites exhibit a wide range of biological activities, suc as cytotoxic, anti-inflammatory, antifouling, and anti-microbials [4][5][6][7][8][9][10][11][12][13][14]. There are some published literature reviews on the genus Sinularia.…”

Cytotoxic Compounds from Alcyoniidae: An Overview of the Last 30 Years

“…Two novel steroidal derivatives, erectsterates A and B, were isolated from Sinularia erecta by Liu et al [139]. Erecsterates B (259) were found to exhibit activity against the proliferation of A-549, HT- Tammam et al [140] isolated twenty-six steroids from the organic extract of Sinularia polydactyla. Among the tested molecules, 7β-acetoxy-24-methyl-cholesta-5,24(28)dien-3β,19-diol (260) and 7β-acetoxy-cholest-5-en-3β,19-diol (261) showed cytotoxic activity against HeLa ((IC 50 values of 7.5 ± 0.1 and 12.0 ± 1.7 µM, respectively) and MCF-7 (IC 50 values of 8.9 ± 0.0 and 11.2 ± 0.5 µM, respectively) cancer cell lines as compared to the control cisplatin ((IC 50 values of 11.4 ± 3.8 and 7.7 ± 1.7).…”

Bioactive Natural Products from the Red Sea

“…Two steroids showed significant cytotoxicity in the low micromolar range against the HeLa and MCF7 cancer cell lines. Additionally, two compounds exhibited neuroprotective activity on neuron-like SH-SY5Y cells [8]. Shaala In the article by Abdelhameed et al, the seagrass Thalassodendron ciliatum (Forssk.)…”