Cembranoids of Soft Corals: Recent Updates and Their Biological Activities

Abstract

Soft corals are well-known as excellent sources of marine-derived natural products. Among them, members of the genera Sarcophyton, Sinularia, and Lobophytum are especially attractive targets for marine natural product research. In this review, we reported the marine-derived natural products called cembranoids isolated from soft corals, including the genera Sarcophyton, Sinularia, and Lobophytum. Here, we reviewed 72 reports published between 2016 and 2020, comprising 360 compounds, of which 260 are new compounds and 100 are previously known compounds with newly recognized activities. The novelty of the organic molecules and their relevant biological activities, delivered by the year of publication, are presented. Among the genera presented in this report, Sarcophyton spp. produce the most cembranoid diterpenes; thus, they are considered as the most important soft corals for marine natural product research. Cembranoids display diverse biological activities, including anti-cancer, anti-bacterial, and anti-inflammatory. As cembranoids have been credited with a broad range of biological activities, they present a huge potential for the development of various drugs with potential health and ecological benefits. Graphic Abstract

Cytotoxic Compounds from Alcyoniidae: An Overview of the Last 30 Years

“…Structural changes in the position of double bonds, epoxidation, allylic and isopropyl oxidation, and carbon cyclization are widely observed in these compounds [183] and often correlated with geographic variation and environmental conditions [184], since cembranoids are used by corals as chemical defense to ensure protection against predators, parasites and competing reef organisms [185]. According to a recent review by Nurrachma et al [186], more than 360 cembranoids are known in the literature. Following Yang et al [187], cembranoids may be divided in 5 subclasses: (1) simple cembranes, including isopropyl cembranes, isopropenyl cembranes, and isopropyl/isopropenyl acid cembranes subtypes;…”

Unusual Cembrane Diterpenoid Isolated from the Japanese Soft Coral Genus Sinularia

“…Therefore, compound 1 can be described as (3E,7E,11E)-16hydroxycembra-13,15-ether-3,7,11-triene, named odosinularol. To the best of our knowledge, the tetrahydrofuran ring that connects C-13 to C-15 is limited to three norcembranoid diterpenes, [18][19][20] chloroscabrolides A-B found in Indonesian soft coral Sinularia sp., 21 and sinularectin found in Kenyan soft coral S. erecta. 22 In contrast, odosinularol (1) is the first example of cembranoid diterpene that contains a tetrahydrofuran ring which connect C-13 to C-15.…”

Uncommon Capnosane Diterpenes with Neuroprotective Potential from South China Sea Soft Coral Sarcophyton boettgeri

“…Cembranoids are a vast family of natural diterpenes mainly found in terrestrial (e.g., plants of the genera Nicotiana [ 1 ] and Pinus [ 2 ]) and marine (e.g., soft corals of the genera Sarcophyton [ 3 , 4 ], Sinularia [ 5 ], Lobophytum [ 6 ], and Alcyonium [ 7 , 8 ]) organisms. The head-to-tail cyclization of a geranylgeranyl diphosphate (GGPP) is considered to generate a 14-membered marcocyclic carbon framework named cembrane [ 9 ].…”

“…[ 16 , 17 ]. From a pharmaceutical point of view, cembranoids have been credited with a broad range of biological activities, including neuroprotective, ichthyotoxic, anticancer, antifouling, antimicrobial, and anti-inflammatory activities [ 1 , 3 , 4 , 6 , 8 , 9 , 20 ]. Moreover, from an ecological point of view, some representative cembranoids are regarded as chemical defense tools to protect soft corals against natural predators, servicing as feeding deterrents or acting by virtue of their toxicities [ 21 ].…”