This review reports details on the natural products isolated from Taiwan soft corals during the period 2008–2012 focusing on their in vitro and/or in vivo anti-inflammatory activities. Chemical structures, names, and literature references are also reported. This review provides useful and specific information on potent anti-inflammatory marine metabolites for future development of immune-modulatory therapeutics.
Five new nardosinane-type sesquiterpenoids, paralemnolins Q–U (1–5), along with three known compounds (6–8), were isolated from the Formosan soft coral Paralemnalia thyrsoides. The structures of new metabolites were elucidated on the basis of extensive spectroscopic methods, and the absolute configuration of 1 was determined by the application of Mosher’s method on 1. Among these metabolites, 1 and 3 are rarely found nardosinane-type sesquiterpenoids, possessing novel polycyclic structures. Compounds 1, 3, 6 and 7 were found to possess neuroprotective activity.
New cembranoids, sarcocrassocolides P–R (1–3) and four known compounds (4–7) were isolated from the soft coral Sarcophyton crassocaule. The structures of the metabolites were determined by extensive spectroscopic analysis. Compounds 3–5 and 7 were shown to exhibit cytotoxicity toward a limited panel of cancer cell lines and all compounds 1–7 displayed potent in vitro anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells by inhibiting the expression of inducible nitric oxide synthase (iNOS) protein. Compound 7 also showed significant activity in reducing the accumulation of cyclooxygenase-2 (COX-2) protein in the same macrophage cells.
Chemical examination of a Taiwanese soft coral Lemnalia philippinensis led to the isolation of three oxygenated ylangene-derived sesquiterpenoids 1–3, including two new metabolites, philippinlins A and B (1 and 2). The structures of these compounds were elucidated on the basis of detailed spectroscopic data. Compound 1 was shown to exhibit cytotoxicity against HepG2, MDA-MB231 and A549 cancer cell lines.
Three new cembranoids, sarcocrassocolides M–O (1–3), have been isolated from the soft coral Sarcophyton crassocaule. The structures of the metabolites were determined by extensive spectroscopic analysis. Compounds 1–3 were shown to exhibit moderate cytotoxicity toward a limited panel of cancer cell lines and display significant in vitro anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells by inhibiting the expression of the iNOS protein.
New eunicellin-type hirsutalins N–R (1–5), along with two known eunicellins, (6 and 7) were isolated from the soft coral Cladiellahirsuta. The structures of the metabolites were determined by extensive spectroscopic analysis. Cytotoxic activity of compounds 1–7 against the proliferation of a limited panel of cancer cell lines was measured. The invitro anti-inflammatory activity of compounds 1–7 was evaluated by measuring their ability in suppressing superoxide anion generation and elastase release in fMLP/CB-induced human neutrophils.