Cembrane Diterpenoids from the Taiwanese Soft Coral Sarcophyton stolidotum

Abstract

Investigation of an EtOAc-soluble extract of the soft coral Sarcophyton stolidotum resulted in the isolation of seven new 14-membered carbocyclic cembranes, sarcostolides A-G (1-7), together with two known cembrane diterpenes, isosarcophytoxide and isosarcophine. The structural elucidation of these metabolites was determined on the basis of spectroscopic analyses, particularly 2D NMR techniques. Sarcostolide E (5) exhibited weak to moderate cytotoxic activity against human WiDr and Daoy tumor cell lines. A biogenetic pathway and relationship for compounds 1-7 was also proposed.

New Diterpenoids from Soft Coral Sarcophyton ehrenbergi

“…These constituents, mainly macrocyclic cembranes and their derivatives, represent important chemical defense substances for the animals against their natural predators [2]. Cembranoids have been previously reported to exhibit a range of biological activities including antitumor [3,4,5,6,7,8,9], ichthyotoxic [10], anti-inflammatory [11], neuroprotective [12], antibacterial [13], antiangiogenic [14], antimetastatic [14], anti-osteoporotic [15], cytotoxic [16,17,18] and antiviral properties [19,20]. …”

Cembrane Diterpenes Chemistry and Biological Properties

“…Gorgonians and soft corals, two groups of coelenterates that belong to the orders Gorgonacea and Alcyonacea respectively, are [45,46,50] Sarcophyton flexuosum 15-17, [11] Sarcophyton stolidotum 372-378 [114] Sarcophyton elegans 18, 19 [12] Sarcophyton cherbonnieri 277, 279, 541 [89] Sarcophyton ehrenbergi 20-23, 204, 205, 263, 542, 543 [13,14] Sarcophyton tortrrosurn 154, 592-594 [58] Sarcophyton tortuosum 585-591 [169,170] Sinularia dissecta 482, 618 [146,176] Sinularia maxima Sinularia polydactyla 516-518, 635-637 [156,180,181] Sinularia maxima 478, 479 [144] Sinularia scabra 507-512 [153][154][155] Sarcophyton crassocaule 440, 441 [17,127,128] Sinularia manaarensis 383-391 [117] Sinularia erecta 498, 500, 609, 610 [151,152] Sinularia leptoclados 491-493 [150] Sinularia lochmodes 496-498, 461 [174,189] Sinularia querciformis 432-435 [126] Sinularia polydactyla 290, 291 [88] Sinularia grandilobata 112-116 [41] [125,150] Sinularia mayi 292-294, 615 [92] Sinularia gyrosaisolated 500-505 [53] Sinularia ovispiculata 56 [26] unidentified soft coral 134-141 [51] Euniceu sp. 52, 58-63, 627-631, 640-644 [24...…”

“…Ten new cembranoid diterpenes, sarcophytonolides C-L (361-370), in that all contain an , -unsaturated butenolactone moiety, were isolated from the Hainan soft coral Sarcophyton latum [57,111,112]. A cluster of analogs, namely isosarcophytonolide D (371) [113], sarcostolides A-G (372-378) [114], brassicolide (379) and brassicolide acetate (380) [115], have been isolated from the soft coral. Two new special cembrane diterpenes (381, 382) have been isolated from an unidentified species of soft coral of the genus Sarcophyton, collected along the South coast of Madagascar [116].…”

Bioactive Cembranoids, Sarcocrassocolides P–R, from the Dongsha Atoll Soft Coral Sarcophyton crassocaule

“…The macrocyclic cembrane-derived compounds are known to be the major diterpenoidal metabolites in soft corals [2,3,4,5,6,7,8,9]. In previous studies of the secondary metabolites from soft corals of Taiwan waters, a series of bioactive cembranoids was discovered from soft corals belonging to the genera Sinularia [10,11,12,13,14,15,16,17], Lobophytum [18,19,20,21], Sarcophyton [22,23,24,25,26,27,28] and Pachyclavularia [29]. Some of these metabolites have been shown to exhibit cytotoxic activity against the growth of various cancer cell lines [11,12,13,15,17,19,20,21,22,23,24,25,26,27,28], and/or anti-inflammatory activity [10,11,14,15,16,17,18,19].…”