Synthesis of novel pyrimidine apiothionucleosides and in vitro evaluation of their cytotoxicity

Synthesis of 4'-Thionucleosides as Antitumor and Antiviral Agents

Many attempts have been made to synthesize structurally novel nucleoside derivatives in order to identify effective compounds for the treatment of tumors and virus-caused disease. At our laboratories, as part of our efforts to synthesize 4'-thionucleosides, we have identified and characterized biologically active nucleosides. During the course of our synthetic study, we developed the Pummerer-type thioglycosylation reaction. As a result, we synthesized a potent antineoplastic nucleoside, 1-(2-deoxy-2-fluoro-β-D-4-thio-arabino-furanosyl)cytosine (4'-thioFAC), and several novel 4'-thionucleosides that possess antiherpes virus activities.

Total synthesis and antimicrobial evaluation of natural albomycins against clinical pathogens

Development of effective antimicrobial agents continues to be a great challenge, particularly due to the increasing resistance of superbugs and frequent hospital breakouts. There is an urgent need for more potent and safer antibiotics with novel scaffolds. As historically many commercial drugs were derived from natural products, discovery of antimicrobial agents from complex natural product structures still holds a great promise. Herein, we report the total synthesis of natural albomycins δ₁ (1a), δ₂ (1b), and ε (1c), which validates the structures of these peptidylnucleoside compounds and allows for synthetic access to bioactive albomycin analogs. The efficient synthesis of albomycins enables extensive evaluations of these natural products against model bacteria and clinical pathogens. Albomycin δ₂ has the potential to be developed into an antibacterial drug to treat Streptococcus pneumoniae and Staphylococcus aureus infections.

Albomycins are promising drug candidates for the treatment of bacterial infections. Here, the authors describe the total syntheses of albomycins δ₁, δ₂, and ε, and evaluate their antimicrobial activity, identifying albomycin δ₂ as a strong agent against S. pneumoniae and S. aureus infections.

Trachycladines and Analogues: Synthesis and Evaluation of Anticancer Activity

The synthesis of four new analogues of marine nucleoside trachycladine A was accomplished by direct regio- and stereoselective Vorbrüggen glycosylations of 2,6-dichloropurine and 2-chloropurine with a d-ribose-derived chiron. Naturally occurring trachycladines A and B and a series of analogues were examined for their cytotoxic activity against a number of cancer cell lines (glioblastoma, lung, and cervical cancer). Parent trachycladine A and two analogues (the diacetate of the 2,6-dichloropurine derivative and N-cyclopropyl trachycladine A) resulted in a significant decrease in cell viability, with the latter exhibiting a stronger effect. The same compounds enhanced the cytotoxic effect of docetaxel in lung cancer cell lines, whereas additional experiments revealed that their mode of action relies on mitotic catastrophe rather than DNA damage. Moreover, their activity as autophagic flux blockers was postulated.