Comparison of In Vitro Binding Affinities of 6R-1, 6S-1 and 2 in Comparison to 6R- and 6S-5-MTHF and Folic Acid to FR-α (n = 3)
| Compound | IC50 (nM) |
| 6R-1 | 27.1 ± 3.7 |
| 6S-1 | 23.8 ± 4.0 |
| 2 | 1.4 ± 0.5 |
| 6R-5-MTHF | 25.8 ± 5.8 |
| 6S-5-MTHF | 20.6 ± 0.4 |
| Folic acid | 0.4 ± <0.1 |
IC50 = half-maximal inhibitory concentration.
Binding curves are available in the supplemental materials.