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.

Keywords: Anti-bacterial; Anti-cancer; Anti-inflammatory; Cembranoids; Diterpene; Lobophytum; Sarcophyton; Sinularia; Soft corals.

Fig. 1

Chemical structures of chembranoid molecules. The isoprene unit of the basic carbon skeleton of cembranoids is bonded head-to-tail (red colors)

Fig. 2

Cembranoids isolated from Sarchophyton sp. (1, 42–47, 85, 92–96) and Sarcophyton subviride (3,4)

Fig. 3

Cembranoids isolated from Sarchophyton trocheliophorum

Fig. 4

Cembranoids isolated from Sarchophyton ehrenbergi

Fig. 5

Cembranoids isolated from Sarcophyton stellatum (32), Sarcophyton mililatensis (54–62, 118–122), Sarcophyton cherbonnieri (69–75, 163–169)

Fig. 6

Cembranoids isolated from Sarchophyton elegans (17–23, and Sarchophyton glaucum (27–31, 106–117, 139)

Fig. 7

Cembranoids isolated from Sarchophyton digitatum (140–147), Sarchophyton tenuispiculatum (148–156) and Sarchophyton roseum (157–162)

Fig. 8

Cembranoids reported from Sinularia erecta (170–172), Sinularia gravis (173), Sinularia nanolobata (174–177), Sinularia compacta (178–180), Sinularia sandensis (181), Sinularia sp. (182–183, 192–194, 400–203), Sinularia flexibilis (184–191, 195–199) and Sinularia scabra (204–211)

Fig. 9

Cembranoids isolated from Sinularia crassa (212–216) and Sinularia humilis (217–222)

Fig. 10

Cembranoids reported from Lobophytum sp

Fig. 11

Cembranoids reported from Lobophytum crassum

Fig. 12

The percentages of cembranoid-producing soft coral species (a). The percentage of different biological activities exhibited by cembranoids (b)