Solvent-Free Mechanosynthesis of Oligopeptides by Coupling Peptide Segments of Different Lengths - Elucidating the Role of Cesium Carbonate in Ball Mill Processes.

We report an idea for the synthesis of oligopeptides using a solvent-free ball milling approach. Our concept is inspired by block play, in which it is possible to construct different objects using segments (blocks) of different sizes and lengths. We prove that by having a library of short peptides and employing the ball mill mechanosynthesis (BMMS) method, peptides can be easily coupled to form different oligopeptides with the desired functional and biological properties.

Synthesis and Characterization of Functionalized Polylactides Containing Acetal Units.

New functionalized lactide copolymers containing acetal units were prepared for the first time in a controlled manner that enabled the regulation of the number of reactive groups introduced into the polyester chain. The presence of functional groups in the copolymer backbone provided chemical modification sites, and the nature of the acetal unit affected the material degradability. First, paraformaldehyde was reacted with selected diols containing reactive pendant groups (3-allyloxypropane-1,2-diol and 3-chloropropane-1,2-diol), which was catalyzed by -toluenesulfonic acid, to synthesize new cyclic acetals with different functionalities (allyl- or chloro-).

Mesoporous Silica Particles as Drug Delivery Systems-The State of the Art in Loading Methods and the Recent Progress in Analytical Techniques for Monitoring These Processes.

Conventional administration of drugs is limited by poor water solubility, low permeability, and mediocre targeting. Safe and effective delivery of drugs and therapeutic agents remains a challenge, especially for complex therapies, such as cancer treatment, pain management, heart failure medication, among several others. Thus, delivery systems designed to improve the pharmacokinetics of loaded molecules, and allowing controlled release and target specific delivery, have received considerable attention in recent years.

Synthesis, Biological Activity and Preliminary in Silico ADMET Screening of Polyamine Conjugates with Bicyclic Systems.

Polyamine conjugates with bicyclic terminal groups including quinazoline, naphthalene, quinoline, coumarine and indole have been obtained and their cytotoxic activity against PC-3, DU-145 and MCF-7 cell lines was evaluated in vitro. Their antiproliferative potential differed markedly and depended on both their chemical structure and the type of cancer cell line. Noncovalent DNA-binding properties of the most active compounds have been examined using ds-DNA thermal melting studies and topo I activity assay.

Synthesis of (1R,2R)- and (1S,2R)-1,2-epoxy-3-hydroxypropylphosphonates as analogues of fosfomycin.

Cyclohexylammonium (1R,2R)-1,2-epoxy-3-hydroxypropylphosphonate was conveniently synthesized from dibenzyl (1S,2R)-2,3-O-cyclohexylidene-1,2,3-trihydroxypropylphosphonate by a reaction sequence including mesylation, hydrolysis of acetal, intramolecular Williamson reaction, and hydrogenation in the presence of cyclohexylamine. For dibenzyl (1S,2R)-2,3-O-cyclohexylidene-1,2,3-trihydroxypropylphosphonates the same approach was not successful, since prior the epoxide-ring closure tritylation of HO-C3 in dibenzyl (1R,2R)-2,3-dihydroxy-1-mesyloxypropylphosphonate was necessary and the hydrogenolysis of dibenzyl (1S,2R)-1,2-epoxy-3-trityloxypropylphosphonate yielded a complex reaction mixture.