Cordycepin and N6-(2-Hydroxyethyl)-Adenosine from Cordyceps pruinosa and Their Interaction with Human Serum Albumin

Abstract

Cordyceps pruinosa (CP) is often used as Traditional Chinese Medicine, but the substance basis of its medicinal properties is unclear. In this study, two compounds were isolated from CP cultures by column chromatography, and identified as cordycepin and N6-(2-hydroxyethyl)-adenosine (HEA) by Nuclear Magnetic Resonance. In order to understand the efficacy of these two substances as potential therapeutic agents, it is necessary to explore their binding with proteins. The molecular mechanisms of interaction between cordycepin, HEA and human serum albumin (HSA) were studied using UV and fluorescence spectroscopy. The bingding constants between HSA and cordycepin were 4.227, 3.573 and 3.076 × 103·at 17, 27 and 37°C respectively, and that of HSA and HEA were 27.102, 19.409 and 13.002 × 103·at the three tempretures respectively. Both cordycepin and HEA can quench the intrinsic fluorescence of HSA via static quenching, and they can bind with HSA to form complexes with a single binding site. The interaction forces between cordycepin and HSA were determined as electrostatic and hydrophobic, and those of HEA and HSA were hydrogen bonding and van der Waals forces. Using Foster's equation, the distance between fluorophores of cordycepin and HSA, and HEA and HSA are estimated to be 5.31 nm and 4.98 nm, respectively. In this study, cordycepin was isolated for the first time from CP, and will provide a new source of cordycepin and expand the use of this taxon. The interaction mechanisms between cordycepin and HSA was studied for the first time, which will provide a useful guide for the clinical application of cordycepin. The pharmacological importance of this study is to understand the interaction of HSA with cordycepin and HEA, which will be essential for the future designing of drugs based on the two compounds.

Beauveria bassiana: a new N6-(2-hydroxyethyl)-adenosine–producing fungus

“…Peng et al (2015) reported that HEA protected mice from renal ischemia reperfusion injury. Studies confirmed that HEA and human serum albumin interacted to form a complex by hydrophobic interaction (Cui et al 2007; Meng et al 2015b). HEA also attenuated lipopolysaccharide-induced pro-inflammatory responses by suppressing the toll-like receptor 4-mediated nuclear factor-κB signalling pathway (Lu et al 2015).…”

Prenatal Developmental Toxicity Study of HEA-enriched Cordyceps Cicadae Mycelia in Sprague-Dawley Rats

“…Although there has been an accumulation of scientific evidence to support its use for treating multiple disorders, no scientific study on its teratogenicity during pregnancy was reported. Moreover, C. cicadae mycelia are a rich source of HEA that has been of interest for centuries in both the traditional medicine and in modern times [27]. Therefore, this study is the first to evaluate the teratogenicity of C. cicadae mycelia, enriched with HEA (1.5 mg/g), in Sprague-Dawley rats.…”

Interaction studies of copper complex containing food additive carmoisine dye with human serum albumin (HSA): Spectroscopic investigations

“…The UV absorption intensity of HSA increased with increase in [Cu(carmoisine) 2 (H 2 O) 2 ] concentration without any shift, implying that the interactions of [Cu(carmoisine) 2 (H 2 O) 2 ] and HSA were non‐covalent interactions . These results implied that the micro‐environment around chromophores of HSA was changed upon addition of the complex . So, the binding of [Cu(carmoisine) 2 (H 2 O) 2 ] to HSA molecule might lead to a change in protein conformation…”