Chemical composition and microbiological evaluation of essential oil from Hyssopus officinalis L. with white and pink flowers

Hyssopus officinalis L. is a common plant that is most usually found in three color forms - f. cyaneus (blue), f. ruber Mill. (purple/pink) and f. albus Alef (white). In the present work, we evaluated the chemical composition and antimicrobial activity of essential oils obtained from Polish-sourced white- and pink-flowered H. officinalis. Gas chromatography-mass spectrometry analysis of the essential oil has shown that both forms of color have a different content of main components. The principle essential oil component of white-flowered H. officinalis L. was pinocamphone (51%), while pink-flowered H. officinalis L. contained almost equal amounts of pinocamphone (28.8%) and isopinocamphone (21.9%). Of note, the essential oil of the pink form was more active against Gram-positive bacteria, especially against Bacillus subtilis.