The effect of two synthetic steroids on the ultrastructure of the liver of rattus norvegicus l

Recent Advances in Enantioselective Organocatalytic Reactions Enabled by NHCs Containing Triazolium Motifs

N-Heterocyclic carbenes (NHCs) containing triazolium motifs have emerged as a powerful tool in organocatalysis. Recently, various NHC pre-catalyst mediated organic transformations have been developed successfully. This article aims to compile the current state of knowledge on NHC-triazolium catalysed enantioselective name reactions and introduce newly developed catalytic methods. Furthermore, this review article framework provides an excellent opportunity to highlight some of the unique applications of these catalytic procedures in the natural product synthesis of biologically active compounds, notably the wide range of preparation of substituted chiral alcohols, and their derivatives. This article provides an overview of chiral NHC triazolium-catalyst libraries synthesis and their catalytic application in enantioselective reactions.

Effect of aflatoxin B1 on hepatic drug-metabolizing enzymes in female rats. Interaction with a contraceptive agent

1. The effect of a contraceptive on aflatoxin B1 toxicity has been studied in female rats treated for 15 consecutive days with repeated doses of aflatoxin (0.40 mg/kg/day), norethindrone (0.60 mg/kg/day) and ethynylestradiol (0.012 mg/kg/day). 2. Increases occurred in hepatic microsomal cytochrome P-450 content (31%), and in the activities of epoxide hydrase (77%), UDP-glucuronyltransferase (67%) and gamma-glutamyltransferase (78%). 3. Aflatoxin alone caused a 22% increase in GSH S-epoxide transferase activity, whereas the contraceptive given alone or combined with aflatoxin increased the hepatic reduced glutathione. 4. The effect of aflatoxin plus contraceptive was not additive. 5. The effects caused by aflatoxin and the contraceptive were similar, and the contraceptive (depending on its progestogen/estrogen ratio), may modify aflatoxin toxicity by increasing the drug-metabolizing enzyme activities and the concentration of hepatic glutathione.