Chiliadenus montanus (Vahl.) Brullo which grows wild in the Jordanian environment shows distinguished Terpinen-4-ol levels and antibacterial powers.

Chiliadenus montanus(Vahl.) Brullo is a wild herb that grows in narrow parts of Jordan and is locally named Hneedeh. Despite being used for treating mild abdominal and respiratory ailments, Hneedeh is still locally known on a very small scale, and its healing capabilities are still waiting for a solid scientific justification. No previous studies were made to explore the antibacterial potential of Jordanian Hneedeh as well as its chemical composition despite being researched by scientists from neighboring countries. For this reason, this research aimed to unveil the active compounds behind the medicinal properties of wild C. montanus collected from Garissa-Jordan by analyzing the essential oil using the GC MS system. Also, the antibacterial activity was explored in two extracts (methanolic and ethanolic) collected from the succulent branches of C. montanus was examined using Microdilution and Disc Diffusion Assays. Data revealed the presence of 23 compounds grouped into eight classes and oxygenated monoterpenes were the predominant class (40.36%).Terpinen-4-ol, which is known for its super curative antibacterial and antitumoral powers, was indicated to be the major chemical compound in the essential oil of Hneedeh as it comprised (23.3%) of the essential oil, which disagreed with other previous studies made on the same plants growing in neighboring counties. Moreover, both extract types restricted growth in most tested bacterial types. The results recorded in the Microdilution Assay showed that the inhibitory effect of both extract types was stronger thanthose obtained in the antibiotic treatment (control) in E. coli and Staphylococcus aureus. Meanwhile, both methanolic and ethanolic extracts were as effective as the antibiotic when administrated to Bacillus subtilis and Salmonella sp. at similar minimal inhibition concentration (MIC) values. Moreover, Disc Diffusion Assay showed that both extract types could prevent the development of six bacteria types while no effect was recorded in Klebsiella pneumoniae. However, E coli bacteria was the most affected strain. The presence of the oxygenated monoterpenes, especially Terpinen-4-ol at premium levels, might be the causal agent behind the remarkable antibacterial powers of C. montanus extract. To our knowledge, this is the first time that C. montanus which grows wild in the village of Ghareesa is reported to contain Terpinen-4-ol as the main active ingredient, which is unlike results reported in other studies conducted on similar plant species growing in other countries. [ABSTRACT FROM AUTHOR]