Enantiomeric behaviour of albendazole and fenbendazole sulfoxides in domestic animals: Pharmacological implications

Albendazole and fenbendazole are methylcarbamate benzimidazole anthelmintics extensively used to control gastrointestinal parasites in domestic animals. These parent compounds are metabolised to albendazole sulfoxide and fenbendazole sulfoxide (oxfendazole), respectively. Both sulfoxide derivatives are anthelmintically active and are manufactured for use in animals. They metabolites have an asymmetric centre on their chemical structures and two enantiomeric forms of each sulfoxide have been identified in plasma, tissues of parasite location and within target helminths. Both the flavin-monooxygenase and cytochrome P450 systems are involved in the enantioselective biotransformation of these anthelmintic compounds in ruminant species. A relevant progress on the understanding of the relationship among enantioselective metabolism and systemic availability of each enantiomeric form has been achieved. This article reviews the current knowledge on the pharmacological implications of the enantiomeric behaviour of albendazole sulfoxide and oxfendazole in domestic animals.     

Identification of flavonoid diglycosides in several genotypes of asparagus from the Huétor-Tájar population variety

The qualitative and quantitative composition of flavonoids from the Huétor-Tájar population variety of asparagus (commonly known as " triguero") was investigated. Flavonoids were analyzed by reversed-phase high-performance liquid chromatography-diode array detection (HPLC-DAD). Liquid chromatography-mass spectrometry (LC-MS) under identical HPLC conditions was used to verify the identities of the flavonoid glycosides from triguero asparagus. The quantities of asparagus flavonoids were calculated according to concentration curves constructed with authentic standards. Total flavonoid contents, calculated as the sum of individual compounds, were determined and ranged from 400 to 700 mg/kg fresh weight. The most abundant was rutin, which represented 55-98% of the total flavonoid complement. Triguero asparagus were revealed to be an important source of not only quercetin derivatives but also kaempferol and isorhamnetin glycosides. Significant differences (p < 0.05) in the content and relative composition of flavonoids were found among the spears of the distinct asparagus genotypes from the Huétor-Tájar population variety.