Cembranoids from the Octocoral Sarcophyton ehrenbergi

Abstract

Chemical investigation of the octocoral Sarcophyton ehrenbergi led to the isolation of six new cembranoids, (+)-12-carboxy-11Z-sarcophytoxide (1), (+)-12-methoxycarbonyl-11Z-sarcophine (3), ehrenberoxides A-C (4-6), and lobophynin C (2), along with two known compounds, (+)-sarcophytoxide (7) and (+)-sarcophine (8). The structures of these isolated metabolites were elucidated through extensive spectroscopic analyses, while the relative configuration of 1 was confirmed by X-ray diffraction analyses. The chemical evidence combined with spectroscopic and physical data suggested that the locations of the epoxide and the methyl carboxylate for lobophynin C should be exchanged. Moreover, metabolites 1-6 were evaluated in vitro for their cytotoxicity against selected cancer and normal cells lines, antiviral activity against human cytomegalovirus, and antibacterial activity against Salmonella enteritidis.

Four New 7,8-Epoxycembranoids from a Chinese Soft Coral <i>Lobophytum</i> sp.

“…[7][8][9][10] Some of these metabolites have been confirmed to play important ecological roles in the life cycle of the corals, such as antifeeding, antifouling, and allelopathy properties, [9][10][11][12] while many of them are also described for biological activities of pharmacological significance, such as antitumor, antiviral, antimicrobial, and antiinflammatory activities. [1][2][3][4][5][6][7][8] All these findings indicate that natural cembranoids of marine origin still merit continuous attention for biomedical research. As part of an ongoing project to search for bioactive natural products from Lobophytum corals inhabited in South China Sea, [13][14][15][16][17] a Hainan soft coral, Lobophytum sp., has been chemically investigated based on the EtOAc extract containing high amounts of terpenoids as detected by 1 resulted in the isolation and characterization of four new 7,8-epoxycembranoids, namely (2S*,7S*,8S*,12R*,1Z,3E,10E)-7,8:2,16-diepoxycembra-1(15),3,10-trien-12-ol (1), (2S*,7S*, 8S*,11R*,1Z,3E)-7,8:2,16-diepoxycembra-1(15), 3,12(20)-trien-11-ol (2), (4S*,7S*,8S*,1Z,2E,11E)-16-acetoxy-7,8-epoxycembra-1(15),2,11-trien-4-ol (3), and (7S*,8S*,15S*,1E,3E,1 1E)-7,8-epoxycembra-1,3,11-trien-15,16-diol (4), along with eleven known analogues 5-15.…”

Cembranoids of Soft Coral Sarcophyton from Acidified Coral Reef Environment at Shallow Water CO2 vents in Volcano Island, Banda Neira, Indonesia

“…Moreover, studies on Indonesian tropical Sarcophyton species usually found other type cembranoid analogues, particularly sarcophytoxide/sarcophine (Iswani, Tohir, & Januar, 2014;Putra, M. Y., Saparhadi, Karim, Murniasih, & Swasono, 2017;Januar, Zamani, Soedharma, & Chasanah, 2017b). Other studies from the temperate region also commonly found more than one type of cembranoid analogue in Sarcophyton species (Pham, Butler, & Quinn, 2002;Cheng et al 2010;Wang et al 2011;Cao, Zhou, Xu, Zhang, & Wang, 2013). The result from this study, which only found sarcophytol analogue as the only cembranoid type in the sample, is rare.…”

Cembrane Diterpenes Chemistry and Biological Properties

“…Two unprecedented cembranoids, methyl tetrahydrosarcoate (18) and methyl tetrahydroisosarcoate (19), have been isolated [12]. Chemical investigation of the octocoral Sarcophyton ehrenbergi led to the isolation of three new simple cembranoids, ehrenberoxides A-C (20)(21)(22) [13]. Moreover, sarcophytol T (23), was isolated from the same species by Konig and his coworker [14].…”

“…The soft coral of genus Sarcophyton are rich sources of cembranoid diterpenes, possessing an -methylidene--lactone moiety, including (+)-12-methoxycarbonyl-11Z-sarcophine (263) [13], trocheliophorol (264) [85], (7R,8S)-dihydroxydeepoxy-entsarcophine (265) [72], sarcocrassocolides A-E (266-270) [86], crassocolides A-F (271-276) [87], (-)-7 -hydroxy-8 -methoxydeepoxysarcophine (277) [88], 13-dehydroxysarcoglaucol-16-one, sarcoglaucol-16-one (278, 279) [89], 16-oxosarcoglaucol acetate (280) [8]. Among these compounds, compounds 266-269 were shown to exert significant in vitro anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells [86].…”

“…Lobophynin C displayed ichthyotoxicity with an LC 100 value of 30 ppm and exhibited toxicity with an LC 50 value of 22.5 ppm in the brine shrimp lethality bioassay [24]. Furthermore, other similar diterpenes were discovered in the soft corals, including sarcophytonin E (540) [161], 13-dehydroxysarcoglaucol (541) [89], (+)-12-carboxy-11Z-sarcophytoxide (542), lobophynin C (543) [13], (-)-7 -hydroxy-8 -methoxydeepoxysarcophytoxide (544), (-)-7 ,8 -dihydroxydeepoxysarcophytoxide (545), and (-)-17-hydroxysarcophytonin A (546) [49], 11,12-epoxy-sarcophytoxide (547) [160]. Sarcophytoxide (548), (2S, 11R, 12R)-isosarcophytoxide (549) [48].…”