Coniferains A and B, new eunicellin-based diterpenoids from the octocoral Cladiella conifera (Tixier-Durivault, 1943)

Marine natural products

“…544 Two publications from the same research group described new xenicane diterpenes, coniferains A–D 1382 – 1385 , isolated from a Taiwanese collection of Cladiella conifera . 545,546 The structure of coniferain A matched that reported in 2010 for australin F, prompting reexamination of NMR data leading in turn to reassignment of the structure of the latter to 1386 . Litophynols C 1387 and D 1388 were isolated from a Ximao Island collection of Cladiella krempfi .…”

Cladiella Octocorals: Enormous Sources of Secondary Metabolites with Diverse Structural and Biological Properties

“…Notably, the absolute configuration of australin E ( 127 ) was unambiguously established as 1 R ,2 R ,3 R ,6 R ,7 S ,10 R ,14 R ,18 R by X‐ray diffraction using Cu Kα radiation in Guo et al .’s investigation [30] . Meanwhile the structure of australin G ( 129 ) was revised as a eunicellin 98 possessing an 11‐methylcyclohexene ring in Sung et al .’s report [41] . In the bioassay, australin E ( 127 ) was found to moderately activate SHIP1 in a dose dependent manner, while the three other new australins 128 – 130 were inactive in the assay ( Figure 13).…”

“…The anti‐inflammatory activity bioassay indicated that compound 93 suppressed the release of COX‐2 to 84.5±2.8 %, compared to the cells stimulated with LPS only at a concentration of 10 μM. The continuing study of this Formosan specimen yielded four new eunicellin‐based diterpenoids, namely, coniferains A−D ( 94 – 97 ) [41,42] . Their structures varied at the different linkages of the ether bridge and the degrees of oxygenation.…”

“…[30] Meanwhile the structure of australin G (129) was revised as a eunicellin 98 possessing an 11-methylcyclohexene ring in Sung et al's report. [41] In the bioassay, australin E (127) was found to moderately activate SHIP1 in a dose dependent manner, while the three other new australins 128 -130 were inactive in the assay (Figure 13).…”

“…The continuing study of this Formosan specimen yielded four new eunicellin-based diterpenoids, namely, coniferains AÀ D (94 -97). [41,42] Their structures varied at the different linkages of the ether bridge and the degrees of oxygenation. Meanwhile the structure of the known diterpene, australin G, [31] was revised as a eunicellin 98 possessing an 11-methylcyclohexene ring.…”