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This article discusses the synthesis and evaluation of saponins with all-nitrogenated sugars (ANS). Aminosugars, a class of modified carbohydrates, have been found in aminoglycosides but have limitations. The creation of artificial aminosugars, such as ANS, offers new possibilities for drug development. Saponins, derived from steroids and triterpenoids, have various biological activities and their sugar moiety plays a critical role. The article describes the synthesis of various ANS-saponin derivatives and their cytotoxicity, showing that ANS-saponins induce apoptosis. [Extracted from the article]

Totally substituted butenolide including two tetrasubstituted olefins is a distinct structural motif seen in Stemona alkaloids, but efficient methods for its synthesis are not well developed. As an ongoing program aimed at the collective total synthesis of the stemoamide group, we report a stereodivergent method to give either (E)- or (Z)-totally substituted butenolide from the same intermediate. While AgOTf--mediated elimination via an E1-type mechanism results in the formation of the kinetic (Z)-tetrasubstituted olefin, subsequent TfOH-mediated isomerization gives the thermodynamic (E)-tetrasubstituted olefin. The pyrrole ring is another important structure found in Stemona alkaloids. The direct oxidation of pyrrolidine rings with MnO2 and careful purification gives the pyrrole groups without isomerization of the stereocenter in the lactone group. These two methods enabled us to synthesize a series of stemoamide-type alkaloids including tricyclic, tetracyclic, and pentacyclic frameworks. The anti-inflammatory activities by inhibition of iNOS expression in macrophage cell line RAW264.7 indicate that the most potent anti-inflammatory compounds without cytotoxicity are protostemonines, which consist of pentacyclic frameworks including the totally substituted butenolide. [ABSTRACT FROM AUTHOR]