Sesquiterpene Lactones from Cotula cinerea with Antibiotic Activity against Clinical Isolates of Enterococcus faecalis

Abstract

Cotula cinerea, belonging to the tribe Anthemideae, is a plant widespread in the Southern hemisphere. It is frequently used in folk medicine in North African countries for several of its medical properties, shown by its extracts and essential oils. The dichloromethane extract obtained from its aerial parts demonstrated antibiotic activity against Enterococcus faecalis and was fractionated by bioguided purification procedures affording five main sesquiterpene lactones. They were identified by spectroscopic methods (NMR and ESIMS data) as guaiantrienolides, i.e., 6-acetoxy-1β-,6-acetoxy-1α-, and 6-acetoxy-10-β-hydroxyguaiantrienolide (1–3), and germacrenolides, i.e., haagenolide and 1,10-epoxyhaagenolide (4 and 5). The absolute configuration was assigned by applying the advanced Mosher’s method to haagenolide and by X-ray diffraction analysis to 1,10-epoxyhaagenolide. The specific antibiotic and antibiofilm activities were tested toward the clinical isolates of Enterococcus faecalis. The results showed that compounds 3–5 have antibacterial activity against all the strains of E. faecalis, while compound 2 exhibited activity only toward some strains. Compound 1 did not show this activity but had only antibiofilm properties. Thus, these metabolites have potential as new antibiotics and antibiofilm against drug resistant opportunistic pathogens.

Antibacterial and Antifungal Sesquiterpenoids: Chemistry, Resource, and Activity

“…Compounds 35 and 36 had antibacterial activity against some strains of Enterobacter faecalis , EF-91804, EF-91823, EF-165, EF-91705, and ATCC29212, and the MICs were 150, 300, 300, 300, and 300µg/mL, respectively. [ 27 ]. Sootepdienone, jambolanins E, jambolanins F, and guaianediol ( 37 – 40 , Figure 4 ) were isolated from the seeds of Eugenia jambolana fruit and exhibited inhibitory activity against S. aureus , with a diameter of the inhibitory zone of 9, 10, 10, and 9 mm, respectively [ 28 ].…”

“…Compound 119 inhibited EF-91804 , EF-91823 , and EF-165 , with the same MIC value of 300 µg/mL , while it only inhibited EF -91705 with a MIC value of 150 µg/mL. Therefore, compounds 118 and 119 can be studied as new antibiotics [ 27 ].…”

Extracts of Brocchia cinerea (Delile) Vis Exhibit In Vivo Wound Healing, Anti-Inflammatory and Analgesic Activities, and Other In Vitro Therapeutic Effects

“…Exposure to either of the two extracts of B. cinerea , ethyl ether or ethyl acetate, for 24 h was active against the mosquito vector of malaria, Anopheles labranchiae , with the LC 50s ranging from 28 to 325 ppm [ 17 ]. The dichloromethane extract obtained from the aerial parts of B. cinerea shows antibiotic activity against the enteric bacterium, Enterococcus faecalis [ 18 ]. Extracts of B. cinera in n-butanol, ethanol, ethyl acetate and petroleum ether at 70% show antimicrobial activity against the bacteria Escherichia coli ( E. coli ), Pseudomonas aeruginosa ( P. aeruginosa ), Staphylococcus aureus ( S. aureus ) and Klebsiella pneumoniae [ 19 ].…”

Bioactive Lipodepsipeptides Produced by Bacteria and Fungi

“…Some of those compounds are either already marketed (daptomycin 37) or in advanced stages of clinical development (ramoplanin 32) for the treatment of complicated infections caused by multidrug-resistant bacterial strains. The development of new antibiotics based on LPDs is of vital importance because MRSA (methicillin resistant Staphylococcus aureus ) strains are rapidly increasing, [ 10 , 11 , 12 , 13 , 14 , 15 ].…”