Cordycepin

Occurrence

It is also produced by Cordyceps kyusyuensis (a close relative of C. militaris), but not by other insect pathogenic fungi such as C. bassiana, C. confragosa, C. takaomontana, Isaria fumosorosea, M. robertsii, and M. rileyi.

Evidence for cordycepin in Ophiocordyceps sinensis (syn. Cordyceps sinensis) has been mixed, and its presence in this species was long considered controversial. More recent analyses using authenticated material and sensitive methods have detected low but measurable amounts: an HPLC–MS/MS study quantified cordycepin at 0.0076–0.029% (w/w) in authenticated wild material, a PLOS ONE comparison reported cordycepin in both cultivated and wild forms (higher on average in cultivated), and independent HPLC work found ~3 ppm in both wild and in‑vitro‑cultured O. sinensis mycelium. Overall, reported detection appears to be sample‑ and method‑dependent.

It is also produced by Samsoniella hepiali (fungus identity confirmed by 18S rRNA) and Aspergillus nidulans Y176-2.

Biosynthesis

The biosynthetic genes for cordycepin were fully characterized in 2017. The same set of genes also produce pentostatin, another adenosine derivative. Pentostatin protects cordycepin from being deaminated in the fungus, allowing the latter to accumulate.

The biosynthetic cluster consists of four genes:

• Cns1 is a oxidoreductase/dehydrogenase.
• Cns2 is a HDc-family metal-dependent phosphohydrolase. There is a binding interaction between Cns1 and Cns2.
• Cns3 is a bifunctional protein. It has an N-terminal (9–101 aa) nucleoside/nucleotide kinase (NK) domain and a C-terminal (681-851 aa) HisG-family ATP phosphoribosyltransferase domain.
• Cns4 is an ABC transporter, specifically of the putative pleiotropic drug resistance (PDR) family.

To produce cordycepin:

• The NK domain of Cns3 converts adenosine into 3′-adenosine monophosphate (3′-AMP, different from the more common 5′-AMP).
• Cns2 removes a phosphate group from 3′-AMP and generates 2′-carbonyl-3′-deoxyadenosine (2′-C-3′-dA).
• Cns1 reduces the carbonyl group on 2′-C-3′-dA into a hydroxyl group, yielding cordycepin.

To produce pentostatin:

• The HisG domain of Cns3 converts adenosine into pentostatin.

Cns4 is able to pump pentostatin out of the cell. One reasonable guess for its function would be that pumping out pentostatin allows cordycepin to be detoxified by deamination (cordycepin is toxic to the fungal cell in excessive concentrations).

Intriguingly, the industrial fungus Acremonium chrysogenum features a gene cluster with high conservation with the Cns cluster, yet the fungus is not observed to produce cordycepin.

Biological activity

Cordyceps fungi produce cordycepin as a means of infecting insect populations, due to its biological activity. Precisely how it works in insects is unknown, but higher cordycepin production is associated with higher larval mortality and more fungus growth. When cordycepin is added to an insect infected by a fungus unable to produce cordycepin, the infection is also enhanced.

Because cordycepin is similar to adenosine, some enzymes cannot discriminate between the two. It can therefore participate in certain biochemical reactions (for example, 3-dA can trigger the premature termination of mRNA synthesis). Cordycepin has displayed cytotoxicity against some leukemic cell lines in vitro. Additionally, cordycepin displays an effect in cancers, such as lung, renal, colon, and breast cancer. Cordycepin reduces viable A549 lung cancer cell populations by 50%.

By acting at RUVBL2, cordycepin is the most potent molecular circadian clock resetter out of several screened compounds. In mice, administration of cordycepin (at 1 hour before lights-out for; 1 hour before lights-on for phase delay) greatly accelerated the adaptation to 8-hour jet lags.

Cordycepin produces rapid, robust imipramine-like antidepressant effects in animal models of depression, and these effects, similarly to those of imipramine, are dependent on enhancement of AMPA receptor signaling. Increased amounts of GSK3β and β-catenin could be another mechanism. Yet another article argues for a role of the gut microbiome while also showing an effect on adipose tissue.

Cordycepin has anti-inflammatory qualities, as well as the ability to defend against injury from cerebral ischemia in mice.

Biotechnology

There is a genome-scale metabolic model (GEM) of Cordyceps militaris called iNR1329. It has been used to find the optimal media C:N ratio for fast growth and cordycepin overproduction of the fungus, at 8:1, with glucose as the carbon source and ammonia as the nitrogen source. The maximal extracellular cordycepin production achieved at the level was 0.3776 g/L (over 7 days). The model-estimated maximal cordycepin production flux was 0.7 mmol/gDW/h.

Wild-type Samsoniella hepiali in submerged cultivation at 25 °C yields 0.26 mg/gDCW over 5 days. With radiation mutagenesis and screening, a mutant strain "ZJB18001" that produces 0.61 mg/g was found.

Pharmacokinetics

Cordycepin readily crosses the blood-brain barrier. It has a very short half-life (between 1 and 2h in cell culture). Pentostatin greatly enhances its clock-resetting effects in cell cultures, likely by preventing deamination.

References

References

1. (1950). "Cordycepin, a Metabolic Product isolated from Cultures of Cordyceps militaris (Linn.) Link.". Nature.
2. (2018-01-01). "An effective and convenient synthesis of cordycepin from adenosine". Chemical Papers.
3. (December 2017). "Fungal Cordycepin Biosynthesis Is Coupled with the Production of the Safeguard Molecule Pentostatin". Cell Chemical Biology.
4. (2019). "Comparative study of the composition of cultivated, naturally grown ''Cordyceps sinensis'', and stiff worms across different sampling years". PLOS ONE.
5. (2015). "Identification of chemical markers in ''Cordyceps sinensis'' by HPLC–MS/MS". Analytical and Bioanalytical Chemistry.
6. (2020). "Adenosine and cordycepin analysis by HPLC in ''Ophiocordyceps sinensis''—a therapeutic miracle fungus". Biochem. Cell. Arch..
7. (2021-11-01). "Improvement of cordycepin production by an isolated Paecilomyces hepiali mutant from combinatorial mutation breeding and medium screening". Bioprocess and Biosystems Engineering.
8. (February 2017). "An Unusual Protector-Protégé Strategy for the Biosynthesis of Purine Nucleoside Antibiotics". Cell Chemical Biology.
9. (April 2021). "Effects of Cordycepin in Cordyceps militaris during Its Infection to Silkworm Larvae". Microorganisms.
10. (1969). "The selective interruption of nucleolar RNA synthesis in HeLa cells by cordycepin". J. Cell Biol..
11. (2012). "Inhibition of polyadenylation reduces inflammatory gene induction". RNA.
12. National Cancer Institute. (2011-02-02). "Definition of cordycepin".
13. (February 2000). "Antileukemic activity and mechanism of action of cordycepin against terminal deoxynucleotidyl transferase-positive (TdT+) leukemic cells". Biochemical Pharmacology.
14. (October 2014). "Synergistic property of cordycepin in cultivated ''Cordyceps militaris''-mediated apoptosis in human leukemia cells". Phytomedicine.
15. (2015). "Apoptotic effect of cordycepin on A549 human lung cancer cell line". Turkish Journal of Biology.
16. (2017-10-18). "Cordycepin promotes apoptosis in renal carcinoma cells by activating the MKK7-JNK signaling pathway through inhibition of c-FLIPL expression". PLOS ONE.
17. (October 2013). "Anti-cancer effect and apoptosis induction of cordycepin through DR3 pathway in the human colonic cancer cell HT-29". Food and Chemical Toxicology.
18. (2019-08-26). "The Inhibitory Effect of Cordycepin on the Proliferation of MCF-7 Breast Cancer Cells, and Its Mechanism: An Investigation Using Network Pharmacology-Based Analysis". Biomolecules.
19. (6 May 2020). "Chemical perturbations reveal that RUVBL2 regulates the circadian phase in mammals". Science Translational Medicine.
20. (2016). "3'-Deoxyadenosine (Cordycepin) Produces a Rapid and Robust Antidepressant Effect via Enhancing Prefrontal AMPA Receptor Signaling Pathway". International Journal of Neuropsychopharmacology.
21. (January 2025). "Cordycepin Extracted from Cordyceps militaris mitigated CUMS-induced depression of rats via targeting GSK3β/β-catenin signaling pathway". Journal of Ethnopharmacology.
22. (December 2023). "Dose-dependent action of cordycepin on the microbiome-gut-brain-adipose axis in mice exposed to stress". Biomedicine & Pharmacotherapy.
23. (March 2021). "Anti-inflammatory effects of cordycepin: A review". Phytotherapy Research.
24. (2011-08-16). "Cordycepin protects against cerebral ischemia/reperfusion injury in vivo and in vitro". European Journal of Pharmacology.
25. (2020). "Optimizing cultivation of Cordyceps militaris for fast growth and cordycepin overproduction using rational design of synthetic media". Computational and Structural Biotechnology Journal.