Two new rare pyrane-based cembranoids, sarcotrocheliol acetate (1) and sarcotrocheliol (2), along with two known cembranoids, cembrene-C (3) and sarcophine (4), and the aromadendrene sesquiterpenoid, palustrol (5), were isolated from the soft coral Sarcophyton trocheliophorum. Chemical structures were determined on the basis of extensive analysis of their spectroscopic data. 1 and 2 displayed significant antibacterial activity, especially against Staphylococcus aureus, Acinetobacter spp., and MRSA with minimal inhibitory concentrations (MICs) ranging from 1.53 to 4.34 lM, while 3 recorded antifungal activity against Aspergillus flavus and Candida albicans with an MIC of 0.68 lM. 4 and 5 showed lower antibacterial and antifungal activities compared to 1, 2, and 3. All the five metabolites displayed no appreciable cytotoxic activity against Artemia salina as test organism, while 4 and 5 recorded antitumor activities against Lymphoma and Erlish cell line with LD 50 in the range of 2.5-3.79 lM.

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Species of the marine red algae Laurencia, are known to exhibit bromine and chlorine-containing C 15 nonterpenoid metabolites.1) Among these, are the unusual cyclic ethers, with a pentadec-3-en-1-yne carbon skeleton. The isolation of trans and cis-laurediols from L. nipponica indicated an evidence that, cyclic ether enynes were raised from linear C 15 acetylenic polyenes, through oxidation and cyclization processes.2) Several maneonenes (halogenated cyclic ether enyne) were isolated from the genus Laurencia, 3-9) the fundamental differences between them is either geometry (through C 3 -C 4 and/or C 12 -C 13 ) and/or stereochemical configuration (C 5 , C 6 and C 11 ).Apoptosis is a programmed form of cell death by which unwanted cells are removed from the body without causing inflammation.10) This contrasts with necrosis, which involves direct damage to cells and is associated with inflammation. 11)Apoptosis may be an alternative and better method by which cells, such as neutrophils, are removed from an inflamed site.12) An organism must also remove senescent, damaged, or abnormal cells that could interfere with organ function or develop into tumors.In the present investigations, we describe the isolation and structural elucidation of three new (cyclic ether enynes) 1, 2 and 3 along with one known isomer 4 5-7) obtained from the petroleum ether extract of the red alga L. obtusa. Results and DiscussionThe petroleum ether extract of the air dried algal material was fractionated on aluminum oxide column using a stepped gradient of hexane and ether. The fractions were examined by spot TLC chromatography and spray reagent methanolsulfuric acid (50%) to give four compounds (1-4).The spectral data of these four compounds (Table 1) showed their very close structural relationship and strongly suggested that they belong to the C 15 acetogenins. The structure of known (12E)-cis-maneonene-A (4) was established by comparing its physical and spectral data with literature. 5-7)Compound 1, was isolated as pale yellow oil. High resolution-electron ionization-mass spectra (HR-EI-MS) established the molecular formula C 15 H 16 BrClO 2 , implying 7 degrees of unsaturation. EI-MS exhibited a characteristic molecular-ion cluster at m/z 342/344/346 in a ratio 2 : 3 : 1, which clearly indicated the presence of one Br and one Cl atoms. The presence of acetylenic group, vinyl ether stretching, and two C-O functionalities were deduced from IR absorptions at n max 3286, 1687, 1126, and 1190 cm Ϫ1 , respectively. Hence, both oxygen atoms could be involved in ether links. The 13 C-NMR and distortionless enhancement by polarization transfer (DEPT) experiments allowed the determination of 1 methyl, 2 methylene, 9 methine and 3 quaternary carbon atoms. Moreover, 13 C-NMR and heteronuclear single quantum coherence (HSQC) spectra displayed resonance for four carbons bearing oxygen, three of these were demonstrated by the signals at d C 78.2, 79.4, and 82.9; while the fourth is of vinyl ether carbon at d C 152.0.The presence of a terminal conjugate...

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Background:Macroalgae can be viewed as a potential antioxidant and anti-inflammatory sources owing to their capability of producing compounds for its protection from environmental factors such as heat, pollution, stress, oxygen concentration, and UV radiations.Objective:To isolate major compounds which are mainly responsible for the pharmacological activity of brown alga under investigation, Sargassum sp.Materials and Methods:Algal material was air dried, extracted with a mixture of organic solvents, and fractionated with different adsorbents. The structures of obtained pure compounds were elucidated with different spectroscopic techniques, and two pure materials were tested for protection of DNA from damage, antioxidant, antitumor, and cytotoxicity.Results:Four pure compounds were obtained, of which fucosterol (1) and fucoxanthin (4) were tested; it was found that fucoxanthin has strong antioxidant and cytotoxicity against breast cancer (MCF-7) with IC50 = 11.5 μg/ml.Conclusion:The naturally highly conjugated safe compound fucoxanthin could be used as antioxidant and as an antitumor compound.