Toxicology of benzyl alcohols: a QSAR analysis

There is an evidence that benzyl alcohols may exhibit toxicity via a radical mechanism. To test this possibility, we studied the toxicity of para substituted benzyl alcohols on rapidly dividing cancer cells (L1210 leukemia). This system has previously found utility in studying the apparent radical toxicity of a variety of phenols. However, no evidence could be found for an electronic effect and the cellular toxicity was associated primarily with hydrophobicity. Comparison of this quantitative structure-activity relationships (QSAR) with others for the reactions of benzyl alcohols in diverse systems provides insight into mechanisms of action. A QSAR for the interaction of benzyl alcohols with protozoa yields an equation that is dependent on both hydrophobicity and acidity of the OH group versus a mixture of bacteria and fungi, the critical dependence on hydrophobicity prevails with a small dependence on a resonance-stabilized, radical mediated electronic effect. The chloramphenicols provide an instructive example, where the radical mediated electronic effect overshadows the hydrophobic contribution to bacterial toxicity. These various QSAR for benzyl alcohols indicate that mechanisms of growth inhibition in vitro vary depending on cell/organism type, the strength of the bond and lability of the hydrogen, and the strength of the initiating radical reagent.     

The Ethiopian mining sector

The Ethiopian Constitution of 1928 vests in the state ownership of all mineral resources. However, the mining code of 1944 recognized the right of individuals and private companies to explore for and develop those resources. The results were quite impressive; Ethiopia became a producer of gold, platinum, copper and other minerals. A revised mining code in 1971 further extended the rights of individuals and companies to develop the mineral resources of the country. In 1974, the newly established revolutionary government eliminated private ownership of mines and established instead state-owned mining companies to develop the mineral resources of the country. In time, the demand for government funding by other sectors of the economy left little for the mining sector and it went into decline. To correct that problem, the Government of Ethiopia in 1989 decided to again make private ownership in the mining sector legal. This paper describes some of the recent initiatives to open the mining sector to private enterprise.