Cherbonolides M and N from a Formosan Soft Coral Sarcophyton cherbonnieri

Abstract

Two new isosarcophine derivatives, cherbonolides M (1) and N (2), were further isolated from a Formosan soft coral Sarcophyton cherbonnieri. The planar structure and relative configuration of both compounds were established by the detailed analysis of the IR, MS, and 1D and 2D NMR data. Further, the absolute configuration of both compounds was determined by the comparison of CD spectra with that of isosarcophine (3). Notably, cherbonolide N (2) possesses the unique cembranoidal scaffold of tetrahydrooxepane with the 12,17-ether linkage fusing with a γ-lactone. In addition, the assay for cytotoxicity of both new compounds revealed that they showed to be noncytotoxic toward the proliferation of A549, DLD-1, and HuCCT-1 cell lines. Moreover, the anti-inflammatory activities of both metabolites were carried out by measuring the N-formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLF/CB)-induced generation of superoxide anion and elastase release in the primary human neutrophils. Cherbonolide N (2) was found to reduce the generation of superoxide anion (20.6 ± 6.8%) and the elastase release (30.1 ± 3.3%) in the fMLF/CB-induced human neutrophils at a concentration of 30 μM.

Cembranolides and Related Constituents from the Soft Coral Sarcophyton cinereum

“…As marine soft corals are a prolific source of bioactive cembranoids, investigations of promising structures with potent bioactivities have been persistently conducted in our laboratory. As part of our continuing search for bioactive structures from marine soft corals [7][8][9][10][11][12], the chemical constituents from the soft coral Sarcophyton cinereum are investigated in this study. Herein, we report the isolation and structural elucidation of three new cembranolides with an α,β-unsaturated ε-lactone (1-3), as well as 16 related cembranoids (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19).…”

“…As part of our continuing search for bioactive structures from marine soft corals [7][8][9][10][11][12], the chemical constituents from the soft coral Sarcophyton cinereum are investigated in this study. Herein, we report the isolation and structural elucidation of three new cembranolides with an α,β-unsaturated ε-lactone (1-3), as well as 16 related cembranoids (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Additionally, their cytotoxicities against a limited panel of cancer cell lines are reported.…”

“…Some of the cembranoid-type compounds have been found to be associated with coral reproduction [ 4 , 5 ]. Previous investigation of the Sarcophyton species has produced metabolites with diverse bioactivities, including anti-viral [ 6 ], anti-inflammatory [ 7 , 8 , 9 , 10 , 11 ], and cytotoxic activities [ 8 , 9 , 10 , 12 ]. As marine soft corals are a prolific source of bioactive cembranoids, investigations of promising structures with potent bioactivities have been persistently conducted in our laboratory.…”

Computationally Assisted Structural Elucidation of Cembranoids from the Soft Coral Sarcophyton tortuosum

“…Soft corals are known to produce a large variety of secondary metabolites [ 1 ]. In particular, soft coral of the genus Sarcophyton is a prolific source of promising bioactive cembranoids, some of which have exhibited antiviral [ 2 ], anti-inflammatory [ 3 , 4 , 5 , 6 , 7 ], and cytotoxic activities [ 4 , 5 , 6 , 8 ]. The flexibility of the macrocyclic ring in cembranoids makes the accurate determination of chemical structures particularly challenging.…”

“…Our pervious investigation on Sarcophyton tortuosum resulted in the isolation of several novel structures, including secotortuosenes A and B with a novel secoditerpenoidal skeleton, bistortuolide cyclobutane A with a novel cyclobutane biscembranoidal skeleton, and tortuosenes A and B with a rare tricyclic diterpenoidal skeleton [ 7 , 11 ]. As part of our continuing effort to explore bioactive marine natural products from soft corals [ 3 , 4 , 5 , 6 , 7 , 8 ], the chemical constituents of S. tortuosum collected at Lanyu Island were investigated in this study, and three new cembranoids, namely tortuolides A and B ( 1 and 2 ) and epi -sarcophytonolide Q ( 3 ), were characterized ( Figure 1 ). Structural elucidations were performed by a comprehensive 2D NMR spectroscopic analysis, as well as computational and statistical analysis methods.…”