Microcystins: Potent xenobiotics

Microbial transformation of xenobiotics

Introduction The term xenobiotic (Greek xenos + bioticos, which means “strange” and “life-related” respectively) means a chemical substance that is not a natural component of a living organism exposed to it, i.e. a strange, exogenous substance or anthropogenic material. This definition covers substances strange to the target organisms, hence its use for most poisons and drugs. An important grou...

Co-oxidation of xenobiotics.

Co-oxidation of xenobiotics has been shown t o occur during prostaglandin synthase (PGS)-catalysed synthesis of prostaglandins (Marnett. 198 I ; EIing et al.. 1983; Marnett & Eling. 1983). PGS catalyses the oxygenation of polyunsaturated fatty acids to hydroxy endoperoxides (e.g. PGH2). The most important substrate in vivo is arachidonic acid (AA) . PGS contains two activities: the fatty acid c...

Biodegradation of Xenobiotics

Phloem Mobility of Xenobiotics

A passive diffusion model has been developed which simultaneously accounts for the dependence of phloem mobility on permeability and acid dissociation. The model is consistent with the observation that the addition of an acid moiety to an otherwise phloem immobile compound may enhance that compound's ability to move in the phloem. However, acid trapping in the basic phloem is not the only enhan...

Xiii. Xenobiotics in Soil