Briarane Diterpenes from the South China Sea Gorgonian Coral, Junceella gemmacea

Abstract

Four new briarane diterpenoids, junceellolides M–P (1–4), were isolated together with seven known analogs (5–11) from the South China Sea gorgonian, Junceella gemmacea. The structures of these compounds were elucidated by detailed spectroscopic analysis and comparison with the reported data. The absolute configuration of compounds 1–3 were determined based on an ECD experiment, while the absolute configuration of compound 4 was genetically determined. All the compounds were isolated for the first time from J. gemmacea. These compounds showed no growth inhibitory activity against A549, MG63 and SMMC-7721 cell lines in an in vitro bioassay.

Fragilolides A-Q, norditerpenoid and briarane diterpenoids from the gorgonian coral Junceella fragilis

“…Compound 9 showed more potent inhibition than the others, while whose structure featured the substitution of an acetoxy group at C-12. The analogues with acyl group at C-13 (3,19) lost the activity, while the exocyclic vinyl group at C-11 of the analogue bearing a diene in C-3/C-4 and C-5/C-6 seems to be critical, due to more active of 12 than those with oxygenated C-11 (13)(14)(15). HBeAg is a protein from the hepatitis B virus and serves as a marker of active viral replication that circulates in infected blood, while the presence of HBeAg suggests that the person is infectious and is able to spread the virus to other people.…”

Chemistry and Bioactivity of Briaranes from the South China Sea Gorgonian Dichotella gemmacea

“…The hydroxyl group was assigned as an α-orientation due to the NOESY correlation of H-13 with H-15. The two isovaleryl groups were deduced to be attached to C-14 and C-16 based on the 2D NMR ( 1 H– 1 H COSY, HMBC) analysis and a comparison to those reported data of analogues [7,8,9,10,11,12]. The relative and absolute configuration of 6 was also proven to be the same as those of 19 by the NOESY and ECD experiments.…”

“…The known compounds dichotelllides O and M ( 8 , 9 ) were once reported from the gorgonian D. gemmacea [13], while gemmacolide C ( 12 ) [18] was previously isolated from the gorgonians J. gemmacea . Juncins P ( 10 ) [14] and ZI ( 11 ) [16] were firstly isolated from the gorgonian J. juncea , and then repeatedly obtained from the gorgonians D. gemmacea [13,20,21], D. fragilis [22], J. gemmacea [7], and J. fragilis [23]. Junceellolide D ( 13 ) [17], (−)-4-deacetoxy junceellolide D ( 14 ) [15], and junceellolide K ( 15 ) [19] were firstly isolated from the gorgonians J. fragilis and then re-isolated from many gorgonian corals, including Verrucella umbraculum [24], J. fragilis [23,25,26,27], D. gemmacea [8,13,20], J. gemmacea [7], Menella sp.…”

“…These metabolites are reported to display a wide spectrum of bioactivities, including cytotoxic, anti-inflammatory, antiviral, antifouling, insecticidal, and immunomodulatory effects [1,2,3,4]. In the course of our searching for novel and bioactive secondary metabolites from the South China Sea invertebrates [5,6,7,8,9,10,11,12], the cluster of metabolites attracted our attention due to their significant tumor tell growth inhibitory activity [7,8,9,10,11,12]. Considering the structural complexity of the metabolites, specific research regarding the determination of absolute configuration was carried out using a solution TDDEFT/ECD approach [12].…”

“…Successive investigation on several collections of the gorgonian Dichotella gemmacea and Junceella gemmacea led to the isolation and structure elucidation of 48 new briaranes and 29 known analogues. On the basis of in vitro screening, a structure–activity relationship analysis of the metabolites was performed [7,8,9,10,11,12]. Three new briaranes, gemmacolides J, V, and Y, showed significant growth inhibitory activity towards A549 cells, being more active than the positive control adriamycin [10,11].…”