Orally active PDE4 inhibitor with therapeutic potential

Cyclic Phosphine Oxides and Phosphinamides from Di-Grignard Reagents and Phosphonic Dichlorides: Modular Access to Annulated Phospholanes

The reaction between 1,4-di-Grignard reagents and phosphonous(III) dichlorides is a classical method for the direct synthesis of phospholanes. Reported here is an extension of this approach to the preparation of value-added, annulated phospholane oxides, achieved through the combination of carbocyclic-fused di-Grignard reagents and readily available phosphonic(V) dichlorides. The procedure is amenable to (benz)annulation at both the 2,3- and 3,4-positions of the phospholane ring, and a variety of aliphatic, cyclic and aryl P-electrophiles are tolerated in reasonable to excellent yields.

SAR studies on hydropentalene derivatives--Important core units of biologically active tetramic acid macrolactams and ptychanolides

Structurally diverse bicyclo[3.3.0]octanes were prepared and tested for their biological activity. Both the antiproliferative activity and the results of phenotypic characterization varied with the substitution patterns. Two derivatives displayed high inhibitory (IC50 ≤3μM) activity against the L-929 cell line, but differed in their mode of action. A cluster analysis with impedance profiling data showed the two compounds in relationship to microtubule interfering compounds. In PtK2 cells treated with both derivatives a perturbing effect on the microtubular network was observed, whereas the actin cytoskeleton in incubated PtK2 cells was disturbed only by one compound. The effects on tubulin and actin polymerization could be confirmed by in vitro polymerization experiments.

Pharmacophore modeling and virtual screening for the discovery of new type 4 cAMP phosphodiesterase (PDE4) inhibitors

Type 4 cAMP phosphodiesterase (PDE4) inhibitors show a broad spectrum of anti-inflammatory effects in almost all kinds of inflamed cells, by an increase in cAMP levels which is a pivotal second messenger responsible for various biological processes. These inhibitors are now considered as the potential drugs for treatment of chronic inflammatory diseases. However, some recently marketed inhibitors e.g., roflumilast, have shown adverse effects such as nausea and emesis, thus restricting its use. In order to identify novel PDE4 inhibitors with improved therapeutic indexes, a highly correlating (r = 0.963930) pharmacophore model (Hypo1) was established on the basis of known PDE4 inhibitors. Validated Hypo1 was used in database screening to identify chemical with required pharmacophoric features. These compounds are further screened by using the rule of five, ADMET and molecular docking. Finally, twelve hits which showed good results with respect to following properties such as estimated activity, calculated drug-like properties and scores were proposed as potential leads to inhibit the PDE4 activity. Therefore, this study will not only assist in the development of new potent hits for PDE4 inhibitors, but also give a better understanding of their interaction with PDE4. On a wider scope, this will be helpful for the rational design of novel potent enzyme inhibitors.

Access to the akuammiline family of alkaloids: total synthesis of (+)-scholarisine A

The planning and implementation of an enantioselective total synthesis of (+)-scholarisine A is presented. Key tactics employed include a novel cyclization, consisting of a nitrile reduction coupled with concomitant addition of the resultant amine to an epoxide; a modified Fischer indolization; an oxidative lactonization of a diol in the presence of an indole ring; and a late-stage cyclization to complete the caged ring scaffold. The development of a possible "retro-biosynthetic" approach to other members of the akuammiline alkaloid family is also described.