Anti-Inflammatory Lobane and Prenyleudesmane Diterpenoids from the Soft Coral Lobophytum varium.

Atallah Ahmed,Wan-Ting Teng,Jyh-Horng Sheu,Chiung-Yao Huang,Tsong-Long Hwang,Chang-Feng Dai

doi:10.3390/md15100300

Abstract

New lobane-based diterpenoids lobovarols A–D (1–4) and a prenyleudesmane-type diterpenoid lobovarol E (5) along with seven known related diterpenoids (6–12) were isolated from the ethyl acetate extract of a Taiwanese soft coral Lobophytum varium. Their structures were identified on the basis of multiple spectroscopic analyses and spectral comparison. The absolute configuration at C-16 of the known compound 11 is reported herein for the first time. The anti-inflammatory activities of compounds 1–12 were assessed by measuring their inhibitory effect on N-formyl-methionyl-leucyl-phenyl-alanine/cytochalasin B (fMLP/CB)-induced superoxide anion generation and elastase release in human neutrophils. Metabolites 2, 5, and 11 were found to show moderate inhibitory activity on the generation of superoxide anion, while compounds 5, 8, 11, and 12 could effectively suppress elastase release in fMLP/CB-stimulated human neutrophil cells at 10 μM. All of the isolated diterpenoids did not exhibit cytotoxic activity (IC50 > 50 μM) towards a limited panel of cancer cell lines.

Highlights

Marine organisms have been well recognized as an important source of natural products with diverse chemical structures and wide array of bioactivities, including the anti-inflammatory activities [1,2,3]
Further separation using a series of normal phase (NP) and reversed phase (RP) silica yielded five new Further separation using a series of normal phase (NP) and reversed phase (RP) silica yielded five diterpenoids lobovarols
We focused on the calculated distances between the diagnostic a conformation analysis using Chem3D, molecular mechanics calculations (MM2) and dihedral driving proton pairs having key nuclear Overhauser effect (NOE) correlations in conformer 1, which were found shorter than 3.0 Å, in calculation were carried out [38,39]

Summary

Introduction

Marine organisms have been well recognized as an important source of natural products with diverse chemical structures and wide array of bioactivities, including the anti-inflammatory activities [1,2,3]. 22 of [8,10], lobane-derived diterpenoids [11,12,13,14], and to a lesser extent of prenyleudesmane-based activities [6,8,10,15,16,19]. The terpenoid metabolites of cembrane-derived including their diterpenoids [12,23,24], have been reported from soft corals belonging [4,5,6,7,8,9,15,16], to the genus Lobophytum. Dimers [8,10], lobane-derived diterpenoids [11,12,13,14], and to a lesser extent of prenyleudesmane-based.

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