Exudate Compounds of Origanum Species

Abstract

Origanum species are valuable medicinal and culinary herbs whose biocidal properties are very important for organic farming. The first substances involved in allelopathic interactions in nature were the exudate (surface) compounds. In the present study, acetone exudates of ten samples of the Origanum species were comparatively analyzed by GC/MS and TLC. Plant material of Origanum dictamnus L., Origanum vulgare L. and Origanum vulgare subsp. hirtum (Link) Ietsw. as the latter taxa represented by eight patterns with different origins were studied. Flavonoid aglycones, terpenes, fatty acids and alcohols, triterpene acids and phenolic derivatives were identified. Methylated derivatives of flavones and non-methylated flavanones (naringenin and eriodictyol) were identified as the most common flavonoid aglycones. The most complex flavonoid profile was detected for O. vulgare ssp. hirtum samples. A few differences in the flavonoid profiles of O. vulgare ssp. hirtum from different origins were found. Carvacrol was determined to be a main component of O. vulgare subsp. hirtum samples, whereas in O. vulgaris exudate long-chain fatty alcohol was found to be an abundant compound. The data obtained complement the knowledge of the distribution and role of exudate compounds.