Four New Briarane Diterpenoids from Taiwanese Gorgonian Junceella fragilis

Abstract

Four new 8-hydroxybriarane diterpenoids, frajunolides P–S (1–4), together with umbraculolide A, juncenolide C, junceellonoid A and juncin R, were isolated from the acetone extract of the gorgonian Junceella fragilis, collected from the southeast coast of Taiwan. Compound 1 contains an unusual pivaloyloxy group at C-2, while 3 is a rare compound having a chlorine atom on the olefinic carbon (C-6). The structures of the isolated compounds were established by extensive spectroscopic analysis, including 1D- and 2D-NMR, as well as HRMS data. Compound 1 was further confirmed by X-ray crystallographic analysis. In the anti-inflammatory test, compounds 1 and 2 exhibited moderate inhibition on superoxide anion generation and elastase release by human neutrophils in response to formylmethionylleucyl-phenylalanine/dihydrocytochalasin B (fMLP/CB).

Anti-Inflammatory and Analgesic Effects of the Marine-Derived Compound Excavatolide B Isolated from the Culture-Type Formosan Gorgonian Briareum excavatum

“…In the present study, we examined the anti-inflammatory effect of excavatolide B, which is a briarane-type diterpene from soft coral, in in vitro and in vivo models. Recent reports have indicated that some marine briarane-type diterpenes from soft coral also have anti-inflammatory potential in LPS-induced macrophages [ 10 , 11 ] or peptide (FMLP/CB)-induced human neutrophil cell models [ 39 , 40 , 41 ]. Moreover, Wei et al has indicated that excavatolide B can reduce the expression of the pro-inflammatory cytokines IL-6 and TNF-α in an LPS-stimulated mouse bone marrow-derived dendritic cell model [ 32 ].…”

Biological Activity of Recently Discovered Halogenated Marine Natural Products

“…The Taiwanese gorgonian Junceella fragilis has afforded eight new 8-hydroxybriarane diterpenoids, frajunolides L–O ( 569 – 572 ) [ 199 ] and P–S ( 573 – 576 ) [ 200 ] ( Figure 110 ). The antiinflammatory activities of these frajunolides were examined by measuring superoxide generation and elastase release by human neutrophils in response to fMLP/CB (formylmethionyl-leucyl-phenylalanine/dihydrocytochalasin B.…”

Fragilides U–W: New 11,20-Epoxybriaranes from the Sea Whip Gorgonian Coral Junceella fragilis

“…The 1 H NMR spectrum indicated the presence of three acetate methyls (H 2.27, 2.25, 2.11, each 3H  s) ( Table 2). The 1 H and 13 C NMR spectra of 3 was found to be similar with those of a known briarane, juncenolide M (= frajunolide S) (7) (Figure 1), isolated from J. juncea and J. fragilis [19,20], except that the signals corresponding to the 13-acetoxy and 3(Z)-ene moieties in 7 were disappeared and replaced by a proton and an (E)-ene moieties in 3, respectively. The locations of the functional groups were confirmed by 2D-NMR correlations (Figure 4), and hence the structure of fragilide W was assigned as 3, and the configurations of the stereogenic carbons were elucidated as 1R,2S,7S,8R,9S,10S,11R, 14S, and 17R ( Figure 4) ( Supplementary Materials, Figures S17-S24).…”