| However, the use of natural coumarin in food was banned in the USA in 1954, and the use of tonka beans restricted to perfume. |
| We modeled the modified complex by replacing the guanine in the native structure with coumarin and allowing rotation about the glycosidic bond. |
| If coumarin is present, a brown, precipitate will form, and if stirred with a rod it will collect in dark green flecks. |
| In this assay a series of sample mixtures with a fixed protein concentration and increasing coumarin concentrations are injected. |
| The coumarin scopoletin is present in whisky, with the highest level reported in Bourbon whiskey. |
| Many plants make use of furocoumarins, in which a coumarin is bonded to a furan ring, as protective substances. |
