Echinohalimane A, a Bioactive Halimane-Type Diterpenoid from a Formosan Gorgonian Echinomuricea sp. (Plexauridae)

Abstract

A new halimane-type diterpenoid, echinohalimane A (1), was isolated from a gorgonian, identified as Echinomuricea sp. The structure of 1 was determined by spectroscopic methods and this compound was found to exhibit cytotoxicity toward various tumor cells and display an inhibitory effect on the release of elastase by human neutrophils. Echinohalimane A (1) is the first halimane analogue from the marine organisms belonging to phylum Cnidaria.

Anti-Inflammatory Activities of Natural Products Isolated from Soft Corals of Taiwan between 2008 and 2012

“…At 10 µg/mL, compounds 180 , 184 , 186 , 188 , 198 – 205 , 208 – 210 , 213 , 216 , 217 , 222 , 232 , 233 , 255 and 261 inhibited the generation of superoxide anion by activated human neutrophils [ 54 , 55 , 56 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 67 , 69 , 70 , 72 ]. Compounds 180 , 184 , 186 , 188 , 202 – 204 , 207 , 210 , 212 , 213 , 215 – 217 , 222 , 232 , 233 , 255 , 260 and 261 inhibited the release of elastase from these activated human neutrophils [ 53 , 54 , 55 , 56 , 59 , 61 , 63 , 65 , 67 , 69 , 71 , 72 ]. These results provided useful baseline information on the immune-regulatory and anti-oxidant activities of various marine diterpenoids.…”

Marine Pharmacology in 2012–2013: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis, and Antiviral Activities; Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action

“…As shown in Table 2, and in contrast to the 20 marine compounds ( 115 – 134 ) with described anti-inflammatory mechanisms of action, for marine compounds ( 135 – 157 ), only anti-inflammatory activity, namely IC 50 , was reported, but the molecular mechanism of action remained undetermined: A. polyacanthus steroids ( 135 , 136 ) [137]; barettin ( 137 ) [138]; briarenolide F ( 138 ) [139]; diketopiperazine ( 139 ) [140]; 6- epi -cladieunicellin F ( 140 ) [141]; crassarosteroside A ( 141 ) [142]; cystodione A ( 142 ) [143]; densanins A and B ( 143 , 144 ) [144]; dissesterol ( 145 ) [145]; echinohalimane A ( 146 ) [146]; eunicidiol ( 147 ) [147]; flexibilisolide C ( 148 ) [148]; flexibilisquinone ( 149 ) [149]; lobocrassin F ( 150 ) [150]; perthamide J ( 151 ) [151]; pseudoalteromone A ( 152 ) [152]; sarcocrassocolide M ( 153 ) [153]; sclerosteroids K and M ( 154 , 155 ) [154]; seco-briarellinone ( 156 ) [155]; and sinularioside ( 157 ) [156]. …”

Natural Product Chemistry of Gorgonian Corals of the Family Plexauridae Distributed in the Indo-Pacific Ocean

“…Two sesquiterpenoids, including new natural product (7 S ,10 R )-(+)-10,11-epoxycurcuphenol ( 28 ) and known metabolite (+)-curcuphenol ( 29 ) [10], along with a new labdane-type diterpenoid, echinolabdane A ( 30 ), a new sterol, 6- epi -yonarasterol B ( 31 ) [11], a new clerodane-type diterpenoid, echinoclerodane A ( 32 ) [12] and a new halimane-type diterpenoid, echinohalimane A ( 33 ) [13], were isolated from the gorgonian coral Echinomuricea sp., collected off the coast of southern Taiwan (Table 6). The structures of metabolites 28 – 33 were elucidated by spectroscopic methods.…”

“…Echinolabdane A ( 30 ) possesses a novel tetracyclic skeleton with an oxepane ring joined to an α,β-unsaturated-γ-lactone ring by a hemiketal moiety [11]. Echinolabdane A ( 30 ), echinoclerodane A ( 32 ) and echinohalimane A ( 33 ) are the first labdane-, clerodane- and halimane-type diterpenoids to be obtained from marine organisms belonging to the phylum Cnidaria, respectively [11,12,13]. …”

“…Clerodane 32 exhibited weak cytotoxicity toward MOLT-4 and HL-60 tumor cells and displayed a significant inhibitory effect on the generation of superoxide anions by human neutrophils [12]. Halimane 33 exhibited cytotoxicity toward K562, MOLT-4, HL-60, DLD-1 and LoVo tumor cells and displayed a significant inhibitory effect on the release of elastase by human neutrophils [13]. …”