Chemical diversity of Sarcophyton soft corals in Okinawa

Abstract

A total of 279 specimens belonging to nine species of soft corals of the genus Sarcophyton were subjected to chemical study for the diversity of cembrane diterpenes. Following morphological identification, each specimen was examined for metabolites using gradient HPLC, NMR, and other tools. The S. glaucum and S. cinereum species complex was found to be the most abundant and to contain the most diverse metabolites in the Ryukyu Archipelago, Japan. S. trocheliophorum and S. ehrenbergi were moderately abundant and diverse in metabolites, while other all species seemed to be scarce and restricted in metabolites. During this research we encountered two new compounds (7,12), whose structures are described in this report.

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

“…The isolation of only three metabolites 20 – 22 (Fig. 2) in their study would correlate with the results of Tanaka et al [52], showing the less complex metabolome of S. trocheliophorum . Exact identification of soft corals is, however still difficult and misidentification cannot be ruled out.…”

“…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]. In this latter study, the largest diversity of secondary metabolites was found for S. glaucum , compared with the moderate chemical diversity found in S. trocheliophorum .…”

“…Interestingly, S. cherbonnieri wherefrom compound 7 was first described, shows no genetic difference to four specimens identified as S. glaucum . The available studies on S. cherbonnieri secondary metabolites [33–34 52] resulted in the isolation of a range of secondary metabolites, some of which were previously described from S. glaucum . These results show that chemotaxonomy might help in effective species delimitation.…”

Cembranoids of Soft Coral Sarcophyton from Acidified Coral Reef Environment at Shallow Water CO2 vents in Volcano Island, Banda Neira, Indonesia

“…These data may link all of the main carbons in cembranoid ring of all isolated compounds. The specific configuration of each compound was found with direct H2BC couplings of carbon with C-13 hydroxyl to H-14 (the same couplings with on the other way around) for sarcophytol B (1), H2BC couplings of epoxide between C-12 to H-11 for 11,12-epoxy sarcophytol A (2), tertiary C-14 with hydroxyl for Sarcophytol A, and quaternary C-1 with hydroxyl for Sarcophytol M. All of the isolated compounds in this study was already characterized previously by Kobayashi, Nakagawa, & Mitsuhashi, (1979) and Kobayashi & Osabe (1989 • 11,12-epoxy sarcophytol A (2) • Sarcophytol M (4) The f inding of sarcophytol A as the major cembranoid compound in Sarcophyton sample was also detected by previous study on the same genus, which are S. crassocaule, S. digtitatum, S. infundibuifurme, and S. glaucum (Koh et al, 2000;Tanaka, Yoshida, & Benayahu, 2005). Meanwhile, Sarcophytol M as a minor sarcophytol analogue was also found from a previous study on S. glaucum (Kobayashi & Osabe, 1989).…”

“…Sarcophine present almost in all Sarcophyton genuses, which are S. glaucum, S. trocheliophorum, S. ehrenbergi, S. elegans, S. infundibuliforme, S. pulchellum, S. cherbonnieri, except in S. crassocaule and S. digitatum (Tanaka, Yoshida, & Benayahu, 2005). S. glaucum sub-species (clade A-F) can be also detected by specific cembranoid content that consists with sarcophine enantiomers (2S,7S,8S-sarcophine, 2S,7R,8R-sarcophine, or 2S,7R,8R-isosarcophine) and sarcophytolide cembranoid analogues (Aratake et al, 2012).…”