epi-Avermectin B1a is a base-catalysed intermediate in the decomposition of Avermectin B1a. Epi-Avermectin B1a is formed by epimerisation at the 2-position which ultimately rearranges irreversibly to the isomeric alkene analog, Delta2-avermectin B1a. Epi-Avermectin B1a is only very weakly active as a nematocide showing ~100-fold loss of biological activity compared with the parent avermectin. Epi-Avermectin B1a is formed in vivo following treatment with avermectin and is an environmental degradation product. Avermectin fractions are designated as A1a, A1b, A2a, A2b, B1a, B1b, B2a, and B2b, with the B1 fraction having the most antiparasitic activity. Avermectins can modulate gamma-aminobutyric acid (GABA) chloride channels in vertebrate neurons.
epi-Avermectin B1a is soluble in ethanol, methanol, DMF or DMSO.
| References | Pivnichny JV et al (1988) Base-catalyzed isomerization of avermectins. J. Agric. Food Chem. 36:826 Pivnichny JV et al (1980) Direct determination of avermectins in plasma at nanogram levels by High-Performance Liquid Chromatography. J. Pharm. Sci. 72:1447 |
