Chemoenzymatic Synthesis of Enantiomeric, Bicyclic δ-Halo-γ-lactones with a Cyclohexane Ring, Their Biological Activity and Interaction with Biological Membranes

New Hydroxylactones and Chloro-Hydroxylactones Obtained by Biotransformation of Bicyclic Halolactones and Their Antibacterial Activity

The aim of this study was to obtain new halolactones with a gem-dimethyl group in the cyclohexane ring (at the C-3 or C-5 carbon) and a methyl group in the lactone ring and then subject them to biotransformations using filamentous fungi. Halolactones in the form of mixtures of two diasteroisomers were subjected to screening biotransformations, which showed that only compounds with a gem-dimethyl group located at the C-5 carbon were transformed. Strains from the genus Fusarium carried out hydrolytic dehalogenation, while strains from the genus Absidia carried out hydroxylation of the C-7 carbon. Both substrates and biotransformation products were then tested for antimicrobial activity against multidrug-resistant strains of both bacteria and yeast-like fungi. The highest antifungal activity against C. dubliniensis and C. albicans strains was obtained for compound 5b, while antimicrobial activity against S. aureus MRSA was obtained for compound 4a.

Red blood cell membrane-camouflaged gold-core silica shell nanorods for cancer drug delivery and photothermal therapy

Gold core mesoporous silica shell (AuMSS) nanorods are multifunctional nanomedicines that can act simultaneously as photothermal, drug delivery, and bioimaging agents. Nevertheless, it is reported that once administrated, nanoparticles can be coated with blood proteins, forming a protein corona, that directly impacts on nanomedicines' circulation time, biodistribution, and therapeutic performance. Therefore, it become crucial to develop novel alternatives to improve nanoparticles' half-life in the bloodstream. In this work, Polyethylenimine (PEI) and Red blood cells (RBC)-derived membranes were combined for the first time to functionalize AuMSS nanorods and simultaneously load acridine orange (AO). The obtained results revealed that the RBC-derived membranes promoted the neutralization of the AuMSS' surface charge and consequently improved the colloidal stability and biocompatibility of the nanocarriers. Indeed, the in vitro data revealed that PEI/RBC-derived membranes' functionalization also improved the nanoparticles' cellular internalization and was capable of mitigating the hemolytic effects of AuMSS and AuMSS/PEI nanorods. In turn, the combinatorial chemo-photothermal therapy mediated by AuMSS/PEI/RBC_AO nanorods was able to completely eliminate HeLa cells, contrasting with the less efficient standalone therapies. Such data reinforce the potential of AuMSS nanomaterials to act simultaneously as photothermal and chemotherapeutic agents.

Microbial Transformations of Halolactones and Evaluation of Their Antiproliferative Activity

The microbial transformations of lactones with a halogenoethylocyclohexane moiety were performed in a filamentous fungi culture. The selected, effective biocatalyst for this process was the Absidia glauca AM177 strain. The lactones were transformed into the hydroxy derivative, regardless of the type of halogen atom in the substrate structure. For all lactones, the antiproliferative activity was determined toward several cancer cell lines. The antiproliferative potential of halolactones was much broader than that observed for the hydroxyderivative. According to the presented results, the most potent was chlorolactone, which exhibited significant activity toward the T-cell lymphoma line (CL-1) cell line. The hydroxyderivative obtained through biotransformation was not previously described in the literature.

Lactones in the Synthesis of Prostaglandins and Prostaglandin Analogs

In the total stereo-controlled synthesis of natural prostaglandins (PGs) and their structural analogs, a vast class of compounds and drugs, known as the lactones, are encountered in a few key steps to build the final molecule, as: δ-lactones, γ-lactones, and 1,9-, 1,11-, and 1,15-macrolactones. After the synthesis of 1,9-PGF2α and 1,15-PGF2α lactones, many 1,15-lactones of E2, E3, F2, F3, A2, and A3 were found in the marine mollusc Tethys fimbria and the quest for understanding their biological role stimulated the research on their synthesis. Then 1,9-, 1,11-, and 1,15-PG lactones of the drugs were synthesized as an alternative to the corresponding esters, and the first part of the paper describes the methods used for their synthesis. The efficient Corey procedure for the synthesis of prostaglandins uses the key δ-lactone and γ-lactone intermediates with three or four stereocenters on the cyclopentane fragment to link the PG side chains. The paper describes the most used procedures for the synthesis of the milestone δ-Corey-lactones and γ-Corey-lactones, their improvements, and some new promising methods, such as interesting, new stereo-controlled and catalyzed enantioselective reactions, and methods based on the chemical/enzymatic resolution of the compounds in different steps of the sequences. The many uses of δ-lactones not only for the synthesis of γ-lactones, but also for obtaining 9β-halogen-PGs and halogen-substituted cyclopentane intermediates, as synthons for new 9β-PG analogs and future applications, are also discussed.

Antiproliferative, Antimicrobial and Antiviral Activity of β-Aryl-δ-iodo-γ-lactones, Their Effect on Cellular Oxidative Stress Markers and Biological Membranes

The aim of this work was the examination of biological activity of three selected racemic cis-β-aryl-δ-iodo-γ-lactones. Tested iodolactones differed in the structure of the aromatic fragment of molecule, bearing isopropyl (1), methyl (2), or no substituent (3) on the para position of the benzene ring. A broad spectrum of biological activity as antimicrobial, antiviral, antitumor, cytotoxic, antioxidant, and hemolytic activity was examined. All iodolactones showed bactericidal activity against Proteus mirabilis, and lactones 1,2 were active against Bacillus cereus. The highest cytotoxic activity towards HeLa and MCF7 cancer cell lines and NHDF normal cell line was found for lactone 1. All assessed lactones significantly disrupted antioxidative/oxidative balance of the NHDF, and the most harmful effect was determined by lactone 1. Contrary to lactone 1, lactones 2 and 3 did not induce the hemolysis of erythrocytes after 48 h of incubation. The differences in activity of iodolactones 1–3 in biological tests may be explained by their different impact on physicochemical properties of membrane as the packing order in the hydrophilic area and fluidity of hydrocarbon chains. This was dependent on the presence and type of alkyl substituent. The highest effect on the membrane organization was observed for lactone 1 due to the presence of bulky isopropyl group on the benzene ring.