Table III.
Inhibition of 11(S),13-dihydrocostunolide and leucodin biosynthesis from (+)-costunolide
| Assay Conditionsa | Percentage Product Formation ± sd
|
|
|---|---|---|
| Dihydrocostunolide (17) | Leucodin (19) | |
| Air (≈80% [v/v] N2+ 20% [v/v] O2) | 100 ± 9b | 100 ± 33b |
| 80% (v/v) CO + 20% (v/v) O2 | 140 ± 4 | 8 ± 1 |
| Argon | 134 ± 6 | 0 ± 0 |
| Control | 100 ± 3c | 100 ± 10c |
| Cytochrome c (100 μm) | 105 ± 5 | 0 ± 0 |
| DMSO (1%) (solvent control) | 100 ± 5d | 100 ± 10d |
| Metyrapone (100 μm) | 87 ± 11 | 70 ± 16 |
| Clotrimazole (10 μm) | 119 ± 9 | 0 ± 0 |
| Miconazole (10 μm) | 100 ± 5 | 0 ± 0 |
| Aminobenzotriazole (10 μm) | 75 ± 8 | 86 ± 33 |
a
All incubations were carried out in the presence of 1 mm NADPH-regenerating system and flavins.
b
One hundred percent product formation corresponds to a saussurea lactone (18) and a leucodin (19) peak size of 1.63 and 0.34 × internal standard (1 nmol of cis-nerolidol), respectively.
c
One hundred percent product formation corresponds to a saussurea lactone (18) and a leucodin (19) peak size of 1.34 and 0.42 × internal standard (1 nmol of cis-nerolidol), respectively.
d
One hundred percent product formation corresponds to a saussurea lactone (18) and a leucodin (19) peak size of 1.43 and 0.18 × internal standard (1 nmol of cis-nerolidol), respectively.