Chemical Constituents and Antibacterial Activity of Essential Oils from Flowers and Stems of Ageratum conyzoides from Ivory Coast

Abstract

The essential oils (EOs) obtained by hydro-distillation of flowers and stems of Ageratum conyzoides L. (Asteraceae) growing in Ivory Coast were investigated. The oils were analyzed and characterized by GC and GC-MS. Analyses of the EOs led to the identification and quantification of 48 constituents in the flower oil and 44 from the stem oil, respectively. Characterization of the EOs revealed the predominance of 6-demethoxyageratochromene or precocene I (flower: 58.8%, stem: 76.5%) and the sesquiterpene β-caryophyllene (flower: 15.2%, stem: 8.1%). Six of the identified compounds β-copaene, hexanal, trans-cadina-1(6),4-diene, α-calacorene, caryophylla-4(12),8(13)-diene-5-β-ol and 1,10-di-epi-cubenol are reported for the first time as constituents of A. conyzoides. Comparative analysis with data from Nigeria, Pakistan, Fiji and Brazil is reported. The antibacterial activity of EOs from of A. conyzoides was tested against seven bacteria. The inhibition zones and minimum inhibitory concentration (MIC) for bacteria strains which were sensitive to A. conyzoides EOs were in the range of 6.7 to 12.7 mm and 64 to 256 μg/mL, respectively. The EOs showed moderate activity against Staphylococcus aureus and Enterococcus faecalis.

Phytonutritional Content and Aroma Profile Changes During Postharvest Storage of Edible Flowers

“…This latter constituent was also found in the aroma profile of the titled species where it represented at least 20% of the total identified fraction. The Ivory Coast flowers EO of Ageratum conyzoides, a plant belonging to the same genus of the species studied herein, was characterized by precocene-I (58.8%) and β-caryophyllene (15.2%) (Kouame et al, 2018), while the EO obtained from the aerial parts of the same species from Nepal revealed both prococene-I (61.7%) and prococene-II (23.5%) as the most important constituent (Satyal et al, 2018).…”

Phytochemical profile of methanolic extracts from Chilca (Baccharis glutinosa) roots and its activity against Aspergillus ochraceus and Fusarium moniliforme

“…The most important of these compounds, are secondary metabolites, like polyphenols, alkaloids, saponin, flavonoids and tannins (Ertani et al, 2015;O'Bryan et al, 2015;Piasecka et al, 2015;Savatin et al, 2014). Recently, these phytochemicals obtained from different parts (roots, stems, leaves) of the plant have been used as bioinsecticides, antifungals, antibacterials, anti-protozoo and antioxidants (Kouame et al, 2018;Bassiri-Jahromi et al, 2015;Granados-Echegoyen et al, 2015;Caballero-Gallardo et al, 2014). It is known that these natural products are extensively used as they are less toxic to humans than most synthetic antifungals, (Pandey et al, 2017;Avaz et al, 2013;Bakkali et al, 2008;Leeja and Thoppil, 2007).…”

Bioassays Guided Fractionation of Ageratum conyzoides Extract for the Identification of Natural Antifungal Compounds against Macrophomina phaseolina

“…Therefore, it was selected for GC-MS analysis that revealed the presence of ten phytoconstituents, some of which also known for their antifungal activities against other fungal species. For intense, compound 2 commonly known as precocene (Kouame et al 2018), has been identified as one of the major components in essential oil of A. conyzoides ranging from 30-93% and inhibited the growth of A. flavus (Castro et al 2004;Esper et al 2015). Iqbal et al (2004) isolated precocene from A. conyzoides and reported that 80-100 ppm concentration of this compound can completely control growth of Sclerotium rolfsii and Rhizoctonia solani.…”