Table 1. Protein Tyrosine Phosphatases 1B (PTP1B) and Human Monoamine Oxidase A (hMAO-A) Inhibitory Activity of Rubrofusarin and Its Glycosidesa.
| PTP1B
inhibition |
hMAO-A inhibition |
|||||
|---|---|---|---|---|---|---|
| compounds | IC50 (μM)b | Ki value (μM) | inhibition typee | IC50 (μM)b | Ki value (μM) | inhibition typee |
| methanol extractf | 14.79 ± 0.31 | 86.89 ± 3.80 | ||||
| rubrofusarin | 16.95 ± 0.49 | 6.99c/18.31d | mixed-competitive | 5.90 ± 0.99 | 4.92c/5.96d | mixed-competitive |
| 1 | 87.36 ± 1.08 | NT | >100 | NT | ||
| 2 | >100 | NT | >100 | NT | ||
| 3 | >100 | NT | 85.50 ± 1.92 | NT | ||
| 4 | >100 | NT | 40.57 ± 0.75 | NT | ||
| ursolic acidg | 2.29 ± 0.04 | NT | NT | |||
| deprenyl HClg | 10.23 ± 0.82 | |||||
a
NT not tested.
b
The 50% inhibition concentration (μM) was calculated from a log-dose inhibition curve and is expressed as the mean ± standard deviation of the triplicate experiments.
c
Binding constant of the inhibitor with the free enzyme (Kic).
d
Binding constant of the inhibitor with the enzyme–substrate complex (Kiu) calculated from secondary plots.
e
Calculated from the Lineweaver–Burk plot.
f
IC50 values are expressed in μg/mL.
g
Used as reference controls.