Attention:

Certain features of sigmaaldrich.com will be down for maintenance Saturday afternoon/evening, February 24th starting at 3:00 pm CT until 9:00 pm CT.

Please note that you still have telephone and email access to our local offices. We apologize for any inconvenience.

Phytochemicals

Some plants produce phytochemicals, such as the furanocoumarins angelicin and psoralen, as a chemical defense against a variety of mammalian and insect predators. In humans, these compounds can interfere with the metabolism of a number of drugs. HPLC is commonly used to screen for the presence of phytochemicals.