Amino Acid-Derived Metabolites from the Ascidian Aplidium sp.

Four new iodobenzene-containing dipeptides (1-4), a related bromotryptophan-containing dipeptide (5), and an iodophenethylamine (6) were isolated from the ascidian Aplidium sp. collected off the coast of Chuja-do, Korea. The structures of these novel compounds, designated as apliamides A-E (1-5) and apliamine A (6) were determined via combined spectroscopic analyses. The absolute configuration of the amino acid residue in 1 was determined by advanced Marfey's analysis. Several of these compounds exhibited moderate cytotoxicity and significant inhibition against Na+/K+-ATPase (4).

Identification of a medicinal off-flavour in mineral water.

The aim of the present study was to identify the compounds responsible for a characteristic medicinal off-odour in mineral water. 2-Dimensional high resolution gas chromatography-mass spectrometry analysis, in combination with olfactometry (HRGC-MS/O), led to the identification of 2-iodophenol and 2-iodo-4-methylphenol as the two compounds exhibiting the medicinal odour notes in mineral water. Determination of odour thresholds of these two compounds in air and water, as well as investigation of their odour characteristics in specific structure-odour activity assays, showed that 2-iodophenol and 2-iodo-4-methylphenol were both extremely potent odour substances with odour thresholds down to 0.03 and 0.0003ng/L air and 0.313 and 0.009mug/L water, respectively. The higher odour potency of 2-iodo-4-methylphenol suggests that this compound is primarily responsible for the medicinal off-odour. Furthermore, the same proportion of the panellists who were not able to detect the off-odour in mineral water exhibited drastically decreased sensibility to 2-iodo-4-methylphenol, but not to 2-iodophenol, which supports this hypothesis.

Removal of 2-fluoro and 2-iodophenol from aqueous solutions using industrial wastes.

A comparative study of the adsorbents prepared from several industrial wastes for the removal of 2-fluorophenol and 2-iodophenol has been carried out. The results show that maximum adsorption on carbonaceous adsorbent prepared from fertilizer industry waste has been found to be 35.3 and 235.3 mg g(-1) for 2-fluorophenol and 2-iodophenol, respectively. Compared to carbonaceous adsorbent, the other three adsorbents (viz., blast furnace sludge, dust, and slag) adsorb phenols to a much smaller extent. This has been attributed to the carbonaceous adsorbent having a larger porosity and consequently higher surface area. The adsorption of phenols on this adsorbent has been studied as a function of contact time, concentration and temperature. The adsorption has been found to be endothermic, and the data conform to the Langmuir equation. The further analysis of data indicates that adsorption is a first order process and pore diffusion controlled. A comparative study of adsorption results with those obtained on standard activated charcoal sample shows that prepared adsorbent is about 45% as efficient as standard activated charcoal and therefore, can be fruitfully employed for the removal of phenolic pollutants from wastewaters.

Rapid radiochemical purity testing for [131I]m-iodobenzylguanidine.

The standard high pressure liquid chromatography (HPLC) method for determining radiochemical purity (RCP) of [131I]m-iodobenzylguanidine ([131I]mIBG) is cumbersome and time-consuming. A simplified and rapid separation method with the use of a reverse-phase extraction chromatography technique (i.e. Sep-Pak C18 [SPC] cartridge) is described. The new SPC system closely correlates (r = 0.99) to the standard HPLC method, and the time to complete the SPC analysis is less than 5 min.