Benzodiazepines: are they of natural origin?

Three research groups have provided evidence that benzodiazepines might be also of natural origin. In the brain of different species including humans and in several plant products, desmethyldiazepam and diazepam are detectable by immunological methods and gas chromatography--mass spectrometry. Thus, benzodiazepines represent natural drugs which may be incorporated into animals and humans through plant products. Whether the measured low concentrations (ranging from 0.01 up to 600 ng/g wet weight) have any biological role or clinical significance remains to be determined.