Metabolic Profiling of the Soft Coral Erythropodium caribaeorum (Alcyonacea: Anthothelidae) from the Colombian Caribbean Reveals Different Chemotypes

Abstract

The Caribbean soft coral Erythropodium caribaeorum is a rich source of erythrolides—chlorinated briarane diterpenoids. These compounds have an ecological role as feeding deterrents, with a wide variation in their composition depending on the location where the sample is collected. In Colombia, this soft coral can be found at different locations in the Caribbean Sea including Santa Marta, Islas del Rosario, and Providencia—three environmentally different coral reef areas in the south and southwest Caribbean Sea. In order to evaluate differences in erythrolide composition, the metabolic profiles of samples from each of these locations were analyzed by HPLC-MS. Principal component analysis showed changes in the diterpene composition according to the sample origin. Diterpenes from samples collected at each location were isolated to describe the three chemotypes. The chemotype from Santa Marta was highly diverse, with the new erythrolides W and X together with eight known erythrolides. The sample from Islas del Rosario showed a low diversity chemotype constituted by high amounts of erythrolide A and B. The chemotype from Providencia showed low chemical diversity with only two main compounds—erythrolide V and R. Evaluation of cytotoxic activity against the human cancer cell lines PC-3, MCF7, and A549 showed erythrolides A and B as the more active compounds with IC50 values in the range from 2.45 to 30 μM.

Briarenols I—K, New Anti-inflammatory 8,17-Epoxybriaranes from the Octocoral Briareum excavatum (Briareidae)

“…Octocorals of the genus Briareum (family Briareidae) [1][2][3][4] are proven to be the most important source to produce briarane-type diterpenoids [5]. The compounds of this type are only found in marine invertebrates, particularly in octocorals and demonstrated a wide spectrum of bioactivities, such as anti-inflammatory activity [6] and cytotoxicity [7]. In our continuing research into the chemical constituents of an octocoral B. excavatum (Nutting 1911), which was distributed extensively in the coral reefs of Taiwan, have resulted in isolation of three previously unreported 8,17-epoxybriaranes-briarenols I-K (1-3) along with two known analogues, briaexcavatolide P (4) [8] and briaexcavatin P (5) [9],…”

“…Structures of briarenols I-K (1-3), briaexcavatolide P (4), briaexcavatin P (5), excavatolide B (6), and briareolide B(7).…”

Cembranoids of Soft Corals: Recent Updates and Their Biological Activities

“…Among these, six known compounds, namely erythrolides A-B 334–335 , erythrolide D 336 , erythrolide F 337 , erythrolide J 338 , and erythrolide U 339, were reported to have new activities. However, the new compounds erythrolides W-X 340–341 showed no biological activities [ 87 ]. Cladiella sp.…”

“…337 exerted anti-proliferation activity against A549, MCF7, and PC3 cancer cell lines with IC 50 values of 37.93, 56.06, and 42.49 μM, respectively. 337 and 338 showed low anti-proliferation activity against the A549 cancer cell line with IC 50 of 46.49 and 36.65 μM, respectively [ 87 ]. Cladiella sp.…”

“…No biological activity was detected in another new compound, 322 , from K. flaccidum [ 83 ], as was the case with a new cembranoid, 324, isolated from J. fragilis [ 84 ], and with 327 derived from aquacultured B. violaceum [ 85 ]. Similarly, no biological activities of interest were recorded in the original published papers of the three novel cembranoids ( 330 , 331 and 332 ) isolated from J. fragilis [ 86 ], two new cembranoids ( 339 and 340 ) from E. caribaeorum [ 87 ], 345 from aquacultured B. violaceum [ 89 ], two novel cembranoids, 349 and 350, from L. flava that originated from Xisha Islands [ 90 ], as well as a novel compound, 355, isolated from the Taiwanese soft coral B. excavatum [ 92 ].…”