Essential Oil of Plectranthus tenuicaulis Leaves from Gabon, Source of (R),(E)-6,7-Epoxyocimene. An Unusual Chemical Composition within the Genus Plectranthus

Abstract

Water distilled essential oils from leaves of Plectranthus tenuicaulis (Hook. f.) J. K. Morton collected in Gabon were analyzed using GC-FID and GC-MS. The main constituent, unusual within the genus Plectranthus, was isolated and formally identified as being the (+)-(R)enantiomer of (E)-6,7-epoxyocimene [(E)-myroxide]. This enantiomer, which represents about 75% of the essential oil, has been previously identified as a pheromone emitted by the male fruit-spotting bug Amblypelta nitida; this insect is responsible of destruction of most fruit crops in tropical and subtropical areas. The potential application of P. tenuicaulis essential oil in crop protection programs is discussed and the atypical chemical profile of the gabonese essential oil is compared with those previously reported in the genus Plectranthus (or Coleus).

Chemical composition, in vitro antioxidant and anti-inflammatory properties of essential oils of four dietary and medicinal plants from Cameroon

“…The EOs were analyzed by gas chromatography and gas chromatography coupled to mass spectrometry as described by Agnaniet et al [ 45 ].…”

Chemical Composition, Antimicrobial, Antioxidant and Cytotoxic Activity of Essential Oils of Plectranthus cylindraceus and Meriandra benghalensis from Yemen

“…Plectranthus species have been used in folk medicine for treating skin, digestive and respiratory diseases [8,9]. Phytochemical studies on Plectranthus species showed the presence of many compounds belonging mainly to the groups of eudesmane sesquiterpenes, labdane, abietane, and ent-kaurane diterpenoids, triterpenoids [10][11][12] and essential oils with monoterpene hydrocarbons, oxygenated monoterpenes and sesquiterpene hydrocarbons as the main components [13][14][15][16][17][18]. P. cylindraceusHoechst.ex.…”

Chemical composition and biological activities of essential oil of Plectranthus tenuicaulis (Hook f.) leaves from Gabon

“…P. tenuicaulis leaves were collected in Mopia (South-eastern Gabon) and analyzed using Gas Chomatography (GC-FID), Gas Chromatography-Mass Spectrometry (GC-MS), 1 H and 13 C NMR (Agnaniet et al, 2011;Agrebi et al, 2012).…”

“…Despite the many papers that have been published on the chemistry of Plectranthus (Abdel-Mogib et al, 2002) before our works (Agnaniet et al, 2011;Agrebi et al, 2012), to our knowledge, there are no previous reports on either the biological or chemical activities of the volatile (or non-volatile) compounds of P. tenuicaulis (Hook).…”