Saponins as cytotoxic agents: a review

Saponins are natural glycosides which possess a wide range of pharmacological properties including cytotoxic activity. In this review, the recent studies (2005–2009) concerning the cytotoxic activity of saponins have been summarized. The correlations between the structure and the cytotoxicity of both steroid and triterpenoid saponins have been described as well as the most common mechanisms of action

On the number of clusterings in a hierarchical classi cation model with overlapping clusters

This paper shows a new combinatorial problem which emerged from studies on an arti cial intelligence classi cation model of a hierarchical classi er. We introduce the notion of proper clustering and show how to count their number in a special case when 3 clusters are allowed. An algorithm that generates all clusterings is given. We also show that the proposed approach can be generalized to any number of clusters, and can be automatized. Finally, we show the relationship between the problem of counting clusterings and the Dedekind problem

Surface Layer Properties after Successive EDM or EDA and Then Superficial Roto-Peen Machining

The paper presents the results of the influence of basic electrical discharge machining EDM parameters and electrical discharge alloying EDA parameters on surface layer properties and on selected performance properties of machine parts after such machining but also the influence of superficial cold-work treatment applied after the EDM of EDA on modification of these properties. The investigations included texture of the surface, metallographic microstructure, microhardness distribution, fatigue strength, and resistance to abrasive wear. It was proved that the application of the roto-peen after the EDM and the EDA resulted in lowering roughness height up to 70%, the elevation of surface layer microhardness by 300–700 μHV, and wear resistance uplifting by 300%

A triterpene saponin from "Lysimachia thyrsiflora L."

A triterpene saponoside (LTS-4) isolated from the underground parts of Lysimachia thyrsiflora L. was defined as 3-O-{β-D-xylopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→2)]-α- L-arabinopyranosyl}-cyclamiretin A. Structure assignment was performed on the basis of spectroscopic data including homo- and heteronuclear 1D and 2D NMR (COSY, TOCSY, NOESY, HETCOR, HMBC and DEPT) and FAB-MS studies. The compound was tested in vitro for antimicrobial and cytotoxic activity

On the number of clusterings in a hierarchical classication model with overlapping clusters

This paper shows a new combinatorial problem which emerged from studies on an artificial intelligence classification model of a hierarchical classifier. We introduce the notion of proper clustering and show how to count their number in a special case when 3 clusters are allowed. An algorithm that generates all clusterings is given. We also show that the proposed approach can be generalized to any number of clusters, and can be automatized. Finally, we show the relationship between the problem of counting clusterings and the Dedekind problem