A catalytic enantioselective vinylogous domino reaction has been achieved from ketone-derived benzylidene Meldrum's acid and ?-ketolactones to provide spirolactone dihydropyranones with more than 99% ee. An Auto Tandem Catalysis (ATC) process resulting dual complementary role of (DHQ)2PHAL organocatalyst resulted in a sequence involving an asymmetric formal (4+2) cycloaddition the subsequent ki...

To investigate the mechanism of action of antimineralocorticoids, a series of spirolactone analogues was evaluated for both mineralocorticoid antagonist and agonist activity. Antagonist activity was assessed by inhibition of aldosterone stimulated sodium transport employing toad bladder short-circuit current (SCC) measurements. Agonist activity was assessed in the same system by the direct effe...

Specific digestion of proteins is an essential step for mass spectrometry-based proteomics, and the chemical labeling of the resulting peptides is often used for peptide enrichment or the introduction of desirable tags. Cleavage of the peptide bond following electrochemical oxidation of Tyr or Trp results in a spirolactone moiety at the newly formed C-terminus offering a handle for chemical lab...

The cDNA of the mineralocorticoid receptor (MR) was cloned 30 years ago, in 1987. At that time, spirolactone, the first generation of synthetic steroid-based MR antagonists (MRAs), which was identified in preclinical in vivo models, had already been in clinical use for 30 years. Subsequent decades of research and development by Searle & Co., Ciba-Geigy, Roussel Uclaf and Schering AG toward iden...

A novel C,D-spirodioxene taxoid (6) was prepared from paclitaxel (1a), with the key steps including an unexpected Pd-mediated ring cyclization. The anti-tubulin activity of 6 was decreased relative to that of 1a and a previously reported C,D-spirolactone taxane (5). These observations could be rationalized on the basis of molecular modeling results. To the best of our knowledge, this is the fir...

The configurational and conformational analyses of α-methylene-γ-butyro steroidal spirolactones have been accomplished using 2D COSY, NOESY, ROESY and HETEROCOSY in conjunction with 1D H NMR. The analyses indicate that the major or the only spirolactones formed at positions 2, 3 and 6 of the steroids have the steroidal ring bearing the spirolactone in a chair conformation with an axial disposit...

Extracts of seven medicinal plants used specifically against cutaneous leishmaniasis in the Madre de Dios region of Peru were evaluated in vitro against promastigote and axenic amastigote forms of Leishmania amazonensis. One of them showed interesting leishmanicidal activities (IC(50)=5 microg/ml in amastigotes). Bio-guided isolation of the stem bark's ethanol extract of Himatanthus sucuuba (Sp...

SINCE the formation of the aqueous humour depends largely upon active transport across the blood-aqueous barrier (in particular the ciliary epithelium), the rate of formation will be influenced by substances which act upon the barrier by modifying its properties or behaviour. In the present paper results are presented which deal with the actions of three different types of substance, all ofwhic...