Essential oil composition of Leucas milanjiana Guerke

Abstract

A hydrodistilled oil obtained from the leaves of Leucas milanjiana Gurke (Lamiaceae) was analysed by capillary GC and GC-MS. The leaf volatile oil contained 30 components, out of which 26 were identified. The predominant components were found to be β β β β β-cubebene (38.15%), α α α α α-pinene (19.71%), trans-caryophyllene (7.41%) and α α α α α-terpinolene (5.34%). The results are qualitatively and quantitatively at variance with data on other Leucas species and may therefore be of some chemotaxonomic significance for the genus.

GC/MS Analysis of the Essential Oil of Leucas indica from India

“…The major constituents of other Leucas species viz., L. aspera contains α-farnesene, α-thujene, menthol, amyl propionate, isoamyl propionate [7], 1-octen-3-ol, (E)-caryophyllene and caryophyllene oxide [8]. In other report from L. milanjiana leaves oil has β-cubebene, α-pinene, trans-caryophyllene and α-terpinolene as the major constituents [9]. According to previous bibliography [10][11][12], the presence of β-caryophyllene in essential oils gives them RI=Retention index relative to C 8 -C 25 n-alkanes on BP-1 column, MS=NIST and Wiley library and the literature, t=trace (<0.1%), CI=Co-injection of commercial samples.…”

Chemical Composition, In Vitro Antimicrobial, Free-Radical-Scavenging and Antioxidant Activities of the Essential Oil of Leucas inflata Benth

“…In former studies, the chemical composition of the volatile oils of various Leucas species, e.g., L. virigata , L. aspera , L. indica , L. glabrata , L. milanjiana and L. deflexa , were investigated [ 17 , 18 , 19 , 20 , 21 , 22 ]. We recently reported the chemical content of the volatile oil of the Soqotraen L. virgate , which was distinguished by a high composition of oxygenated monoterpenes (50.8%).…”

“…Whereas Joshi (2014) [ 23 ] confirmed the dominance of β-caryophyllene (51.1%) in the L. indica essential oil, Vagionas et al (2007) [ 22 ] found that the fundamental chemical class in L. glabrata is oxygenated monoterpenes (64.4%), with menthone (31.8%) and pulegone (11.4%) as essential constituents. Moreover, high contents of β-cubebene (38.1%), α-pinene (19.7%), and trans-caryophyllene were detected in L. milanjiana oil [ 19 ]. Additionally, the investigation performed on the volatile oil of the L. deflexa leaves revealed a high amount of sesquiterpene hydrocarbons (80.3%) with germacrene- d (27.8%), β-caryophyllene (24.1%) and α-humulene (9.9%) as major components [ 21 ].…”

A review: Ethnobotanical survey of genus Leucas

“…[ 68 ] However, the essential oil fraction from the leaves and flowers of Leucas aspera were found to contain high amount of afarnesene, a-thujene, and menthol;[ 69 70 ] whereas, high content of b- cubebene, a-pinene, trans-caryophyllene, limonene, and a-terpineolene were reported in the essential oil from Leucas milanjiana . [ 71 ] The essential oil fraction of Leucas deflexa leaf was reported to have a high amount of sesquiterpene hydrocarbons, namely, germacrene-D, b- caryophyllene, and a-humulene. [ 72 ] A new type of diterpenes, leucasperones A and B; leucasperols A and B, have been reported from Leucas aspera .…”