Antimicrobial thymohydroquinones of Moroccan Nigella sativa seeds detected by electron spin resonance

Analysis of the black seeds of Nigella sativa L. (Ranunculaceae) by electron spin resonance (ESR) revealed the presence of a high content of thymohydroquinones. Furthermore, antimicrobial tests of the crude seed extract against ten microbial species, including two fungi, showed activity against Bacillus subtilis, Klebsiella pneumoniae, Mycobacterium phlei and methicillin sensitive and resistant Staphylococcus aureus. The seeds are used in Moroccan traditional medicine for pulmonary diseases including coughs as well as for other ailments.