Antibacterial Performance of Terpenoids from the Australian Plant Eremophila lucida

Abstract

Plants in the Australian genus Eremophila (Scrophulariaceae) have attracted considerable recent attention for their antimicrobial compounds, which possess a wide range of chemical structures. As they are typically associated with the oily-waxy resin layer covering leaves and green branchlets, and Eremophila lucida is prominent among the species containing a pronounced sticky resin layer, this species was considered of interest for assessing its antibacterial constituents. The n-hexane fraction of the crude acetone extract of the leaves exhibited antibacterial activity against Staphylococcus aureus. Isolation led to the known compounds cembratriene, (3Z, 7E, 11Z)-15-hydroxycembra-3,7,11-trien-19-oic acid (1), the sesquiterpenoid, farnesal (2) and the viscidane diterpenoid, 5α-hydroxyviscida-3,14-dien-20-oic acid (3). The purified compounds were tested for antibacterial activity with 2 and 3 showing moderate antibacterial activity against Gram-positive bacteria.

Anti-Methicillin-Resistant Staphylococcus aureus Activities of Artocarpus lakoocha Roxb Extract and Its Mode of Action

“…This result was supported by several studies indicating that A. lakoocha Roxb was a very good source of antimicrobial agents, antioxidants, and phenolic compounds. Common extraction solvents used to obtain extracts with antimicrobial and antioxidant activities and phenolic content were ethanol, methanol, ethyl acetate, and acetonitrile [ 10 , 14 – 19 ].…”

Antimicrobial Effect of Natural Berry Juices on Common Oral Pathogenic Bacteria

“…Because of these reasons, natural plant extracts are constantly under investigation for evaluation of their antimicrobial capability [ 26 , 27 , 28 ]. Observations from these studies might help to design new and efficient anti-infective and bioactive agents with fewer side effects for safe and efficient microbial control.…”

Navigating through chemical space and evolutionary time across the Australian continent in plant genusEremophila

“…Extracts from Eremophila species have been tested for anti-viral [15], anti-bacterial [16][17][18] and anti-cancer [19] activity, and show inhibitory activity of ion channels [20]. Isolated serrulatane-and viscidane-type diterpenoids exhibit anti-malarial [21], anti-bacterial [7,[22][23][24][25][26][27], anti-diabetic [10,11], and anti-inflammatory [22,24] properties. The presence and biosynthesis of interesting metabolites in species of Myoporeae have previously been demonstrated [10-14, 18, 21, 28] and recent phylogenetic studies have revealed complex evolutionary relationships between genera in the tribe [29,30].…”