Abstract
Based on our previous finding that certain cembranoid diterpenes possess selective toxicity against protozoan pathogens of tropical diseases such as Trypanosoma and Plasmodium, we have subjected a series of 34 cembranes isolated from soft corals living in the Vietnamese sea to an in vitro screening for anti-protozoal activity against Trypanosoma brucei rhodesiense (Tbr), T. cruzi (Tc), Leishmania donovani (Ld), and Plasmodium falciparum (Pf). Twelve of the tested compounds displayed significant activity against at least one of the parasites. Specifically, 7S,8S-epoxy-1,3,11-cembratriene-16-oic methyl ester (1), (1R,4R,2E,7E,11E)-cembra-2,7,11-trien-4-ol (2), crassumol D (12), crassumol E (13), and (1S,2E,4S,6E,8S,11S)-2,6,12(20)-cembrantriene-4,8,11-triol (16) from Lobophytum crassum, L. laevigatum, and Sinularia maxima showed the highest level of inhibitory activity against T. b. rhodesiense, with IC50 values of about 1 µM or less. Lobocrasol A (6) and lobocrasol C (8) from L. crassum and L. laevigatum exhibited particularly significant inhibitory effects on L. donovani with IC50 values < 0.2 µM. The best antiplasmodial effect was exerted by laevigatol A (10), with an IC50 value of about 3.0 µM. The cytotoxicity of the active compounds on L6 rat skeletal myoblast cell was also assessed and found to be insignificant in all cases. This is the first report on anti-protozoal activity of these compounds, and points out the potential of the soft corals in discovery of new anti-protozoal lead compounds.
Highlights
Neglected tropical diseases (NTDs) are a group of seventeen mostly life threatening and/or disabling infections affecting more than a billion people worldwide
Secondary metabolites produced by diverse marine organisms represent a huge repository of chemical structures for searching new drugs which can contribute to improved public health conditions in tropical developing countries [7,8]
In the course of our ongoing search for secondary metabolites with anti-protozoal activity from marine organisms [9], we recently reported on our study of methanolic extracts of the soft corals
Summary
Neglected tropical diseases (NTDs) are a group of seventeen mostly life threatening and/or disabling infections affecting more than a billion people worldwide. The search for new drugs against these diseases is an urgent need and natural sources such as marine organisms with their extremely diverse secondary metabolites may play an important role [1]. Secondary metabolites produced by diverse marine organisms represent a huge repository of chemical structures for searching new drugs which can contribute to improved public health conditions in tropical developing countries [7,8]. In the course of our ongoing search for secondary metabolites with anti-protozoal activity from marine organisms [9], we recently reported on our study of methanolic extracts of the soft corals. We report on the results of in vitro activity tests of 34 cembranoid diterpenes (Figure 1), isolated as major pure constituents from.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
