Two new polyhydroxylated steroids from Egyptian soft coral Heteroxenia fuscescens (Fam.; Xeniidae)

Secondary Metabolites from Marine Sources with Potential Use as Leads for Anticancer Applications

“…In the last 5 years, several studies have been carried out with the aim of evaluating the bioactive properties of marine organisms. Several studies have tested the extracts and the isolated compounds from extracts of marine organisms for bioactivities [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ], of which the cytotoxic activity [ 27 , 30 , 32 , 33 , 35 , 36 , 37 , 38 , 40 , 41 , 44 , 45 , 46 , 47 , 48 ] stands out. However, only in some studies was it possible to isolate the compounds and test them for cytotoxic activity [ 32 , 33 , 35 , 36 , 37 , 38 , 40 , 41 ].…”

“…Our first choice involves steroid derivatives ( Figure 2 ) isolated from marine organisms such as the sea urchins Diadema setosum (Leske, 1778) and Diadema savignyi (Audouin, 1809) [ 35 , 56 , 57 ], and the corals Heteroxenia fuscescens (Ehrenberg, 1834), Heteroxenia ghardaqensis (Gohar, 1940), and Lobophytum lobophytum , including from Sinularia and Sarcophyton species [ 32 , 37 , 58 , 59 , 60 , 61 , 62 , 63 ], but also isolated from the sponges Haliclona crassiloba (de Laubenfels, 1950) and Cliona copiosa (Sarà, 1959) [ 64 , 65 ], and the marine invertebrate Microcosmus vulgaris (Heller, 1877) [ 36 ].…”

“…Of the sterols isolated in H. fuscescens [ 32 , 37 ] ( Table 2 , Figure 2 ), compounds ( 10 ), ( 11 ), ( 15 ), and ( 16 ) are new natural sterols. Compound ( 12 ) was isolated for the first time from natural sources, although it was previously obtained by synthesis [ 66 ].…”

“…These IC 50 values are lower than the control used in the study, vinblastine, for which the IC 50 values for MCF-7 and OVK-18 were 65.23 ± 5.59 μM and 43.65 μM, respectively [ 37 ]. Compounds ( 13 ) to ( 17 ) were tested only against the MCF-7 cell line, with 5-fluorouracil as a positive control [ 32 ]. Only compound ( 14 ) and compound ( 16 ) showed relevant cytotoxicity against the MCF-7 cell line, with an IC 50 of 33.2 μM and 25.1 μM, respectively, when compared to the control (IC 50 = 18.7 μM) [ 32 ].…”

“…Compounds ( 13 ) to ( 17 ) were tested only against the MCF-7 cell line, with 5-fluorouracil as a positive control [ 32 ]. Only compound ( 14 ) and compound ( 16 ) showed relevant cytotoxicity against the MCF-7 cell line, with an IC 50 of 33.2 μM and 25.1 μM, respectively, when compared to the control (IC 50 = 18.7 μM) [ 32 ]. The results obtained suggest that the substitution of the side chain by a carbonyl group greatly reduces the cytotoxic activity of sterol [ 37 ].…”