Acetyl‐ and Butyryl‐cholinesterase Inhibitory Activities of Mansorins and Mansonones

Abstract

Cholinesterase (ChE) inhibitory activities of three coumarins (mansorins A-C) and five naphthoquinones (mansonone C, E, G and H) were evaluated to determine the relationships between the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory effects and the core structures of these compounds. Among the tested compounds, mansonone E exhibited the highest ChE inhibitory activities, with IC₅₀ values in the low micromolar levels. In addition to revealing the ChE inhibitory activities of naphthoquinones for the first time, the results also revealed structure-activity relationship information that could be useful for further modification. Furthermore, the study also supports the hypothesis that mansonones are the active component in Thespesia populnea, a plant that previously has been shown to enhance memory activity in an in vivo study.

Natural AChE Inhibitors from Plants and their Contribution to Alzheimer’s Disease Therapy

“…A study conducted on AChE and BChE inhibitory activity of coumarins and naphtoquinones obtained from Mansonia gagei (Sterculiaceae) proposed a novel class of cholinesterase inhibitor, mansonones or 1,2-naphtoquinones [69]. The level of cholinesterase inhibition observed in this study seemed to correlate to the presence of a fused pyran ring and a substituent at C-6 being present in the molecule.…”

Nature as a source of metabolites with cholinesterase-inhibitory activity: an approach to Alzheimer's disease treatment

“…The presence of a fused pyran ring favours anti‐ChE activity: masonones E and H, having this feature, are more active than mansonones C and G, which do not present this characteristic. In contrast, the presence of a hydroxyl group at C6 induces a decrease of the inhibitory activity: mansonones C and E are more active than mansonones G and H, respectively …”

“…Mimulone 91.5 Human erythrocytes [56] 20.6 Equine serum [56] Naringenin 2045 Human erythrocytes [56] 1494 Equine serum [56] Pomiferin 96 Electric eel [57] N.F. Horse serum [57] Quercetin 353.9 Pacific electric ray [58] 420.8 Horse serum [58] Rutin 28.2 Electric eel [59] 44.6 Horse serum [59] Tamarixetin 22.3 N.M. [54] 160.6 N.M. [54] Quinones Mansonone E 23.5 Electric eel [60] 62.4 Horse serum [60] Sargaquinoic acid 23.3 N.M. [61] 0.026 N.M. [61] Stilbenes (+)-a-Viniferin 2.0 N.M. [62] N.F. Gnetol N.F.…”

Acetylcholinesterase Inhibitory Activity of Pigment Echinochrome A from Sea Urchin Scaphechinus mirabilis

“…Among quinone-related compounds, it has been reported that the IC 50 values of sargaquinoic acid and mansonones E are 23.3 and 23.5 μM, respectively [12]. In our experimental setting, the anti-AChE activity of EchA was better than other quinone-related compounds, sargaquinoic acid and mansonones E [30]. However, direct comparison of compounds on anti-AChE activity needs caution, since the inhibitory concentrations of tested compounds are dependent on incubation time, reaction conditions, source of enzymes and assaying method [8].…”