OBJECTIVE Gelidium amansii (Lamouroux) is a red alga belonging to the family Gelidaceae and is commonly found in the shallow coasts of many East Asian countries, including Korea, China, and Japan. G. amansii has traditionally been utilized as an edible alga, and has various biological activities. The objective of this study was to determine whether dietary supplementation of G. amansii could be...

A new butenolide derivative (1), along with three known compounds (2-4) were isolated from the MeOH extract of brown alga Sargassum micracanthum. The structures 1 to 4 determined by analyses 1D and 2D NMR mass spectroscopic data. identified as (5 E,10 Z)-6,10,14-trimethylpentadeca-5,10-dien-2,12-dione (2), E,9 E)-6,10,14-trimethylpentadeca-5,9-dien-2,12-dione (3), (-)-loliolide (4) comparing th...

The methanolic extract of the cyanobacterium (blue-green alga) Spirulina geitleri has been treated with methanolic acid to convert all chlorophyllous pigments to their methylpheophorbides. Fractionation of the latter from methylpheophorbide a by thin layer chromatography and high pressure liquid chromatography yielded methylpheophorbide-RCI. Its structure has been determined as 13’shydroxy-20-c...

Four new (1-4) and six previously reported (5-10) α-pyrone polyketides, along with benzoic acid, hydrocinnamic acid, and (E)-cinnamic acid, were isolated from the organic extract resulting from the cultivation of the algicolous strain Streptomyces ambofaciens BI0048, which in turn was isolated from the inner tissues of the red alga Laurencia glandulifera. The structure elucidation of the isolat...

Algae have long been used to augment plant productivity through their beneficial effects. Alginate oligosaccharide is believed to be one of the important components to enhance growth and crop yield. In this study, we isolated and characterized a Bacillus litoralis strain, named Bacillus M3, from decayed kelps. We further demonstrated that the M3 strain could secrete alginate lyase to degrade al...

A combination of on-line HPLC-NMR and off-line chemical investigations has resulted in the identification of the previously reported polyhalogenated monoterpene plocamenone, together with the new structural analogue isoplocamenone from the crude extract of the marine alga Plocamium angustum. On-flow and stop-flow HPLC-NMR analyses (including the acquisition of WET 2D NMR spectra) rapidly assist...

Chromatographic fractionation of the CH₂Cl₂/MeOH extract of the Red Sea red alga Laurencia obtusa gave two new hexahydrofuro[3,2-b]furan-based C15-acetogenins, namely, isolaurenidificin (1) and bromlaurenidificin (2). The chemical structures were elucidated based on extensive analyses of their spectral data. Compounds 1 and 2 showed no toxicity (LC50 > 12 mM) using Artemia salina as test organi...

Using laboratory assays, we tested whether the secondary metabolites (furanones) on the surface of the red alga Delisea pulchra deter the settlement and growth of a range of ecologically relevant fouling organisms. D. pulchra and 4 other co-occurring seaweeds were almost exclusively fouled by other algae. Consequently, we carried out laboratory assays using propagules from 4 fouling algae (Ulva...

In recent years, a significant number of novel metabolites with potent pharmacological properties (antioxidant, antitumor, anti-HIV etc.) have been discovered from the marine organisms. Kappaphycus alvarezii (Doty). Being an invasive in the Gulf of Mannar after 2000 AD, has high content of steroid, phenol etc., this work was the first report of its medical application. The present study investi...

A soil amoeba, Hartmannella glebae, could grow on a variety of gram-positive and gram-negative bacteria, although the rate of growth was faster in the presence of gram-negative bacteria. The amoeba, however, could not use yeasts, molds, or a green alga as a nutritional source. The extract prepared from amoebae grown in the presence of Aerobacter aerogenes and Alcaligenes faecalis could lyse int...