Lobophytones U – Z₁, Biscembranoids from the Chinese Soft Coral Lobophytum pauciflorum

Abstract

Chemical examination of a Chinese soft coral Lobophytum pauciflorum resulted in the isolation of seven new biscembranoids named lobophytones U-Z(1) (1-7, resp.), together with methyl sartortuoate (8) and nyalolide (9). The structures of the new compounds were elucidated by 1D- and 2D-NMR (COSY, HSQC, HMBC, and NOESY) spectroscopic analysis in association with MS and IR data. All compounds were tested against lipopolysaccharide (LPS)-induced nitric oxide (NO) release in mouse peritoneal macrophage. Lobophytone Z (6) inhibited NO production with an IC(50) value of 2.6 μM. Lobophytone H (1) showed inhibitory activities against the bacteria S. aureus and S. pneumoniae.

Four New 7,8-Epoxycembranoids from a Chinese Soft Coral <i>Lobophytum</i> sp.

“…[1][2][3][4][5][6][7][8] All these findings indicate that natural cembranoids of marine origin still merit continuous attention for biomedical research. As part of an ongoing project to search for bioactive natural products from Lobophytum corals inhabited in South China Sea, [13][14][15][16][17] a Hainan soft coral, Lobophytum sp., has been chemically investigated based on the EtOAc extract containing high amounts of terpenoids as detected by 1 resulted in the isolation and characterization of four new 7,8-epoxycembranoids, namely (2S*,7S*,8S*,12R*,1Z,3E,10E)-7,8:2,16-diepoxycembra-1(15),3,10-trien-12-ol (1), (2S*,7S*, 8S*,11R*,1Z,3E)-7,8:2,16-diepoxycembra-1(15), 3,12(20)-trien-11-ol (2), (4S*,7S*,8S*,1Z,2E,11E)-16-acetoxy-7,8-epoxycembra-1(15),2,11-trien-4-ol (3), and (7S*,8S*,15S*,1E,3E,1 1E)-7,8-epoxycembra-1,3,11-trien-15,16-diol (4), along with eleven known analogues 5-15. The structures of known compounds were identified by comparison of their 1 H-and 13 C-NMR spectroscopic data and optical rotations with those reported in the literature.…”

Cytotoxic Biscembranoids from the Soft Coral <i>Sarcophyton pauciplicatum</i>

“…The three isolated carbonyl groups of ring A with adjacent chirality centers (2S,9R,12S) of 1 was suggested by circular dichroism (CD) spectrum in methanol with two positive bands at 282 and 205 nm. 10,11) The relative configuration at C-1, C-2, C-5, C-9, C-12, and C-21 was assigned by agreement of the 1 H-and 13 C-NMR data of 1 with those of lobophytone Z 1 , 8) and coexistence of 1 and 3-10 in S. pauciplicatum. In the rotating frame nuclear Overhauser effect spectroscopy (ROESY), the correlations of H-38 (δ H 1.79) with H-21 (δ H 3.38), H-26 (δ H 3.51), and H-30 (δ H 3.45); H-26 (δ H 3.51) with H-39 (δ H 1.07); and that of H-30 (δ H 3.45) with 35-OMe (δ H 3.07) suggesting that H-21, H-26, H-30, the methyl group C-39, and the methoxy group at C-35 are all in α-orientation.…”

“…1) were isolated from the methanol extract of the Vietnamese soft coral S. pauciplicatum by using various chromatographic methods. The known compounds were elucidated as sarcophytolide I (3), 6) sarcophytolide J (4), 6) sarcophytolide L (5), 6) lobophytone O (6), 7) lobophytone U (7), 8) methyl tortuoate A (8), 9,10) methyl tortuoate B (9), [9][10][11] methyl sartortuoate (10), 6,10,12) by detailed analysis of their spectroscopic data (one dimensional (1D)-and 2D-NMR and MS) and comparison with literature values.…”

Secondary metabolome and its defensive role in the aeolidoidean Phyllodesmium longicirrum, (Gastropoda, Heterobranchia, Nudibranchia)

“…Other closely related soft corals, such as Lobophytum spp., also contain cembranoids, e.g., the isosarcophytoxides 10 and 11 [36] as well as a numerous biscembranoid compounds [51]. Distinct patterns of chemotypes in Sarcophyton species were demonstrated in a study by Tanaka et al [52].…”