Synthesis of 3',4'-difluoro-3'-deoxyribonucleosides and its evaluation of the biological activities: discovery of a novel type of anti-HCV agent 3',4'-difluorocordycepin

Cordycepin: A review of strategies to improve the bioavailability and efficacy

Cordycepin is a bioactive compound extracted from Cordyceps militaris. As a natural antibiotic, cordycepin has a wide variety of pharmacological effects. Unfortunately, this highly effective natural antibiotic is proved to undergo rapid deamination by adenosine deaminase (ADA) in vivo and, as a consequence, its half-life is shortened and bioavailability is decreased. Therefore, it is of critical importance to work out ways to slow down the deamination so as to increase its bioavailability and efficacy. This study reviews recent researches on a series of aspects of cordycepin such as the bioactive molecule's pharmacological action, metabolism and transformation as well as the underlying mechanism, pharmacokinetics and, particularly, the methods for reducing the degradation to improve the bioavailability and efficacy. It is drawn that there are three methods that can be applied to improve the bioavailability and efficacy: to co-administrate an ADA inhibitor and cordycepin, to develop more effective derivatives via structural modification, and to apply new drug delivery systems. The new knowledge can help optimize the application of the highly potent natural antibiotic-cordycepin and develop novel therapeutic strategies.

4'-Fluoro-nucleosides and nucleotides: from nucleocidin to an emerging class of therapeutics

The history and development of 4'-fluoro-nucleosides is discussed in this review. This is a class of nucleosides which have their origin in the discovery of the rare fluorine containing natural product nucleocidin. Nucleocidin contains a fluorine atom located at the 4'-position of its ribose ring. From its early isolation as an unexpected natural product, to its total synthesis and bioactivity assessment, nucleocidin has played a role in inspiring the exploration of 4'-fluoro-nucleosides as a privileged motif for nucleoside-based therapeutics.

Anti-inflammatory effects of cordycepin: A review

Cordycepin is the major bioactive component extracted from Cordyceps militaris. In recent years, cordycepin has received increasing attention owing to its multiple pharmacological activities. This study reviews recent researches on the anti-inflammatory effects and the related activities of cordycepin. The results from our review indicate that cordycepin exerts protective effects against inflammatory injury for many diseases including acute lung injury (ALI), asthma, rheumatoid arthritis, Parkinson's disease (PD), hepatitis, atherosclerosis, and atopic dermatitis. Cordycepin regulates the NF-κB, RIP2/Caspase-1, Akt/GSK-3β/p70S6K, TGF-β/Smads, and Nrf2/HO-1 signaling pathways among others. Several studies focusing on cordycepin derivatives were reviewed and found to down metabolic velocity of cordycepin and increase its bioavailability. Moreover, cordycepin enhanced immunity, inhibited the proliferation of viral RNA, and suppressed cytokine storms, thereby suggesting its potential to treat COVID-19 and other viral infections. From the collected and reviewed information, this article provides the theoretical basis for the clinical applications of cordycepin and discusses the path for future studies focusing on expanding the medicinal use of cordycepin. Taken together, cordycepin and its analogs show great potential as the next new class of anti-inflammatory agents.